mirror of https://gitee.com/openkylin/linux.git
1507 Commits
Author | SHA1 | Message | Date |
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Alexander Duyck | d483da5bc7 |
mm: create non-atomic version of SetPageReserved for init use
It doesn't make much sense to use the atomic SetPageReserved at init time
when we are using memset to clear the memory and manipulating the page
flags via simple "&=" and "|=" operations in __init_single_page.
This patch adds a non-atomic version __SetPageReserved that can be used
during page init and shows about a 10% improvement in initialization times
on the systems I have available for testing. On those systems I saw
initialization times drop from around 35 seconds to around 32 seconds to
initialize a 3TB block of persistent memory. I believe the main advantage
of this is that it allows for more compiler optimization as the __set_bit
operation can be reordered whereas the atomic version cannot.
I tried adding a bit of documentation based on
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Michal Hocko | 2c029a1ea3 |
mm, page_alloc: drop should_suppress_show_mem
should_suppress_show_mem() was introduced to reduce the overhead of
show_mem on large NUMA systems. Things have changed since then though.
Namely
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Johannes Weiner | eb414681d5 |
psi: pressure stall information for CPU, memory, and IO
When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | b29940c1ab |
mm: rename and change semantics of nr_indirectly_reclaimable_bytes
The vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES was introduced by
commit
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Oscar Salvador | 7b0e0c0e35 |
mm/page_alloc.c: clean up check_for_memory()
check_for_memory() looks a bit confusing. First of all, we have this: if (N_MEMORY == N_NORMAL_MEMORY) return; Checking the ENUM declaration, looks like N_MEMORY canot be equal to N_NORMAL_MEMORY. I could not find where N_MEMORY is set to N_NORMAL_MEMORY, or the other way around either, so unless I am missing something, this condition will never evaluate to true. It makes sense to get rid of it. Moving forward, the operations within the loop look a bit confusing as well. We set N_HIGH_MEMORY unconditionally, and then we set N_NORMAL_MEMORY in case we have CONFIG_HIGHMEM (N_NORMAL_MEMORY != N_HIGH_MEMORY) and zone <= ZONE_NORMAL. (N_HIGH_MEMORY falls back to N_NORMAL_MEMORY on !CONFIG_HIGHMEM systems, and that is why we can just go ahead and set N_HIGH_MEMORY unconditionally) Although this works, it is a bit subtle. I think that this could be easier to follow: First, we should only set N_HIGH_MEMORY in case we have CONFIG_HIGHMEM. And then we should set N_NORMAL_MEMORY in case zone <= ZONE_NORMAL, without further checking whether we have CONFIG_HIGHMEM or not. Link: http://lkml.kernel.org/r/20180828210158.4617-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michael Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 15f570bf3d |
mm,page_alloc: PF_WQ_WORKER threads must sleep at should_reclaim_retry()
Tetsuo Handa has reported that it is possible to bypass the short sleep
for PF_WQ_WORKER threads which was introduced by commit
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Srikar Dronamraju | e054637597 |
mm, sched/numa: Remove remaining traces of NUMA rate-limiting
Remove the leftover pglist_data::numabalancing_migrate_lock and its
initialization, we stopped using this lock with:
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Mel Gorman | efaffc5e40 |
mm, sched/numa: Remove rate-limiting of automatic NUMA balancing migration
Rate limiting of page migrations due to automatic NUMA balancing was introduced to mitigate the worst-case scenario of migrating at high frequency due to false sharing or slowly ping-ponging between nodes. Since then, a lot of effort was spent on correctly identifying these pages and avoiding unnecessary migrations and the safety net may no longer be required. Jirka Hladky reported a regression in 4.17 due to a scheduler patch that avoids spreading STREAM tasks wide prematurely. However, once the task was properly placed, it delayed migrating the memory due to rate limiting. Increasing the limit fixed the problem for him. Currently, the limit is hard-coded and does not account for the real capabilities of the hardware. Even if an estimate was attempted, it would not properly account for the number of memory controllers and it could not account for the amount of bandwidth used for normal accesses. Rather than fudging, this patch simply eliminates the rate limiting. However, Jirka reports that a STREAM configuration using multiple processes achieved similar performance to 4.16. In local tests, this patch improved performance of STREAM relative to the baseline but it is somewhat machine-dependent. Most workloads show little or not performance difference implying that there is not a heavily reliance on the throttling mechanism and it is safe to remove. STREAM on 2-socket machine 4.19.0-rc5 4.19.0-rc5 numab-v1r1 noratelimit-v1r1 MB/sec copy 43298.52 ( 0.00%) 44673.38 ( 3.18%) MB/sec scale 30115.06 ( 0.00%) 31293.06 ( 3.91%) MB/sec add 32825.12 ( 0.00%) 34883.62 ( 6.27%) MB/sec triad 32549.52 ( 0.00%) 34906.60 ( 7.24% Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jirka Hladky <jhladky@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux-MM <linux-mm@kvack.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20181001100525.29789-2-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Aneesh Kumar K.V | 464c7ffbcb |
mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.
When scanning for movable pages, filter out Hugetlb pages if hugepage migration is not supported. Without this we hit infinte loop in __offline_pages() where we do pfn = scan_movable_pages(start_pfn, end_pfn); if (pfn) { /* We have movable pages */ ret = do_migrate_range(pfn, end_pfn); goto repeat; } Fix this by checking hugepage_migration_supported both in has_unmovable_pages which is the primary backoff mechanism for page offlining and for consistency reasons also into scan_movable_pages because it doesn't make any sense to return a pfn to non-migrateable huge page. This issue was revealed by, but not caused by |
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Mukesh Ojha | 13ba17bee1 |
notifier: Remove notifier header file wherever not used
The conversion of the hotplug notifiers to a state machine left the notifier.h includes around in some places. Remove them. Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1535114033-4605-1-git-send-email-mojha@codeaurora.org |
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Naoya Horiguchi | d4ae9916ea |
mm: soft-offline: close the race against page allocation
A process can be killed with SIGBUS(BUS_MCEERR_AR) when it tries to allocate a page that was just freed on the way of soft-offline. This is undesirable because soft-offline (which is about corrected error) is less aggressive than hard-offline (which is about uncorrected error), and we can make soft-offline fail and keep using the page for good reason like "system is busy." Two main changes of this patch are: - setting migrate type of the target page to MIGRATE_ISOLATE. As done in free_unref_page_commit(), this makes kernel bypass pcplist when freeing the page. So we can assume that the page is in freelist just after put_page() returns, - setting PG_hwpoison on free page under zone->lock which protects freelists, so this allows us to avoid setting PG_hwpoison on a page that is decided to be allocated soon. [akpm@linux-foundation.org: tweak set_hwpoison_free_buddy_page() comment] Link: http://lkml.kernel.org/r/1531452366-11661-3-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: <zy.zhengyi@alibaba-inc.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Oscar Salvador | 03e85f9d5f |
mm/page_alloc: Introduce free_area_init_core_hotplug
Currently, whenever a new node is created/re-used from the memhotplug path, we call free_area_init_node()->free_area_init_core(). But there is some code that we do not really need to run when we are coming from such path. free_area_init_core() performs the following actions: 1) Initializes pgdat internals, such as spinlock, waitqueues and more. 2) Account # nr_all_pages and # nr_kernel_pages. These values are used later on when creating hash tables. 3) Account number of managed_pages per zone, substracting dma_reserved and memmap pages. 4) Initializes some fields of the zone structure data 5) Calls init_currently_empty_zone to initialize all the freelists 6) Calls memmap_init to initialize all pages belonging to certain zone When called from memhotplug path, free_area_init_core() only performs actions #1 and #4. Action #2 is pointless as the zones do not have any pages since either the node was freed, or we are re-using it, eitherway all zones belonging to this node should have 0 pages. For the same reason, action #3 results always in manages_pages being 0. Action #5 and #6 are performed later on when onlining the pages: online_pages()->move_pfn_range_to_zone()->init_currently_empty_zone() online_pages()->move_pfn_range_to_zone()->memmap_init_zone() This patch does two things: First, moves the node/zone initializtion to their own function, so it allows us to create a small version of free_area_init_core, where we only perform: 1) Initialization of pgdat internals, such as spinlock, waitqueues and more 4) Initialization of some fields of the zone structure data These two functions are: pgdat_init_internals() and zone_init_internals(). The second thing this patch does, is to introduce free_area_init_core_hotplug(), the memhotplug version of free_area_init_core(): Currently, we call free_area_init_node() from the memhotplug path. In there, we set some pgdat's fields, and call calculate_node_totalpages(). calculate_node_totalpages() calculates the # of pages the node has. Since the node is either new, or we are re-using it, the zones belonging to this node should not have any pages, so there is no point to calculate this now. Actually, we re-set these values to 0 later on with the calls to: reset_node_managed_pages() reset_node_present_pages() The # of pages per node and the # of pages per zone will be calculated when onlining the pages: online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_zone_range() online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_pgdat_range() Also, since free_area_init_core/free_area_init_node will now only get called during early init, let us replace __paginginit with __init, so their code gets freed up. [osalvador@techadventures.net: fix section usage] Link: http://lkml.kernel.org/r/20180731101752.GA473@techadventures.net [osalvador@suse.de: v6] Link: http://lkml.kernel.org/r/20180801122348.21588-6-osalvador@techadventures.net Link: http://lkml.kernel.org/r/20180730101757.28058-5-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Oscar Salvador | 0188dc98ad |
mm/page_alloc: inline function to handle CONFIG_DEFERRED_STRUCT_PAGE_INIT
Let us move the code between CONFIG_DEFERRED_STRUCT_PAGE_INIT to an inline function. Not having an ifdef in the function makes the code more readable. Link: http://lkml.kernel.org/r/20180730101757.28058-4-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | 7cc2a9596d |
mm: remove __paginginit
__paginginit is the same thing as __meminit except for platforms without sparsemem, there it is defined as __init. Remove __paginginit and use __meminit. Use __ref in one single function that merges __meminit and __init sections: setup_usemap(). Link: http://lkml.kernel.org/r/20180801122348.21588-4-osalvador@techadventures.net Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | c1093b746c |
mm: access zone->node via zone_to_nid() and zone_set_nid()
zone->node is configured only when CONFIG_NUMA=y, so it is a good idea to have inline functions to access this field in order to avoid ifdef's in c files. Link: http://lkml.kernel.org/r/20180730101757.28058-3-osalvador@techadventures.net Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Oscar Salvador | ace1db3976 |
mm/page_alloc.c: move ifdefery out of free_area_init_core
Patch series "Refactor free_area_init_core and add free_area_init_core_hotplug", v6. This patchset does three things: 1) Clean up/refactor free_area_init_core/free_area_init_node by moving the ifdefery out of the functions. 2) Move the pgdat/zone initialization in free_area_init_core to its own function. 3) Introduce free_area_init_core_hotplug, a small subset of free_area_init_core, which is only called from memhotlug code path. In this way, we have: free_area_init_core: called during early initialization free_area_init_core_hotplug: called whenever a new node is allocated/re-used (memhotplug path) This patch (of 5): Moving the #ifdefs out of the function makes it easier to follow. Link: http://lkml.kernel.org/r/20180730101757.28058-2-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aaron Lu | d8a759b570 |
mm, page_alloc: double zone's batchsize
To improve page allocator's performance for order-0 pages, each CPU has a Per-CPU-Pageset(PCP) per zone. Whenever an order-0 page is needed, PCP will be checked first before asking pages from Buddy. When PCP is used up, a batch of pages will be fetched from Buddy to improve performance and the size of batch can affect performance. zone's batch size gets doubled last time by commit ba56e91c9401("mm: page_alloc: increase size of per-cpu-pages") over ten years ago. Since then, CPU has envolved a lot and CPU's cache sizes also increased. Dave Hansen is concerned the current batch size doesn't fit well with modern hardware and suggested me to do two things: first, use a page allocator intensive benchmark, e.g. will-it-scale/page_fault1 to find out how performance changes with different batch sizes on various machines and then choose a new default batch size; second, see how this new batch size work with other workloads. In the first test, we saw performance gains on high-core-count systems and little to no effect on older systems with more modest core counts. In this phase's test data, two candidates: 63 and 127 are chosen. In the second step, ebizzy, oltp, kbuild, pigz, netperf, vm-scalability and more will-it-scale sub-tests are tested to see how these two candidates work with these workloads and decides a new default according to their results. Most test results are flat. will-it-scale/page_fault2 process mode has 10%-18% performance increase on 4-sockets Skylake and Broadwell. vm-scalability/lru-file-mmap-read has 17%-47% performance increase for 4-sockets servers while for 2-sockets servers, it caused 3%-8% performance drop. Further analysis showed that, with a larger pcp->batch and thus larger pcp->high(the relationship of pcp->high=6 * pcp->batch is maintained in this patch), zone lock contention shifted to LRU add side lock contention and that caused performance drop. This performance drop might be mitigated by others' work on optimizing LRU lock. Another downside of increasing pcp->batch is, when PCP is used up and need to fetch a batch of pages from Buddy, since batch is increased, that time can be longer than before. My understanding is, this doesn't affect slowpath where direct reclaim and compaction dominates. For fastpath, throughput is a win(according to will-it-scale/page_fault1) but worst latency can be larger now. Overall, I think double the batch size from 31 to 63 is relatively safe and provide good performance boost for high-core-count systems. The two phase's test results are listed below(all tests are done with THP disabled). Phase one(will-it-scale/page_fault1) test results: Skylake-EX: increased batch size has a good effect on zone->lock contention, though LRU contention will rise at the same time and limited the final performance increase. batch score change zone_contention lru_contention total_contention 31 15345900 +0.00% 64% 8% 72% 53 17903847 +16.67% 32% 38% 70% 63 17992886 +17.25% 24% 45% 69% 73 18022825 +17.44% 10% 61% 71% 119 18023401 +17.45% 4% 66% 70% 127 18029012 +17.48% 3% 66% 69% 137 18036075 +17.53% 4% 66% 70% 165 18035964 +17.53% 2% 67% 69% 188 18101105 +17.95% 2% 67% 69% 223 18130951 +18.15% 2% 67% 69% 255 18118898 +18.07% 2% 67% 69% 267 18101559 +17.96% 2% 67% 69% 299 18160468 +18.34% 2% 68% 70% 320 18139845 +18.21% 2% 67% 69% 393 |
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Michal Hocko | 9ea9a68064 |
mm: drop VM_BUG_ON from __get_free_pages
There is no real reason to blow up just because the caller doesn't know that __get_free_pages cannot return highmem pages. Simply fix that up silently. Even if we have some confused users such a fixup will not be harmful. [akpm@linux-foundation.org: mask off __GFP_HIGHMEM] Link: http://lkml.kernel.org/r/20180622162841.25114-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jiankang Chen <chenjiankang1@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yisheng Xie <xieyisheng1@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | d6a24df006 |
mm, page_alloc: actually ignore mempolicies for high priority allocations
__alloc_pages_slowpath() has for a long time contained code to ignore node restrictions from memory policies for high priority allocations. The current code that resets the zonelist iterator however does effectively nothing after commit |
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Pavel Tatashin | 720e14ebec |
mm: skip invalid pages block at a time in zero_resv_unresv()
The role of zero_resv_unavail() is to make sure that every struct page that is allocated but is not backed by memory that is accessible by kernel is zeroed and not in some uninitialized state. Since struct pages are allocated in blocks (2M pages in x86 case), we can skip pageblock_nr_pages at a time, when the first one is found to be invalid. This optimization may help since now on x86 every hole in e820 maps is marked as reserved in memblock, and thus will go through this function. This function is called before sched_clock() is initialized, so I used my x86 early boot clock patches to measure the performance improvement. With 1T hole on i7-8700 currently we would take 0.606918s of boot time, but with this optimization 0.001103s. Link: http://lkml.kernel.org/r/20180615155733.1175-1-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | b018fc9800 |
Power management updates for 4.19-rc1
- Add a new framework for CPU idle time injection (Daniel Lezcano). - Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT). - Add support for current CPU frequency reporting to the ACPI CPPC cpufreq driver (George Cherian). - Rework the cooling device registration in the imx6q/thermal driver (Bastian Stender). - Make the pcc-cpufreq driver refuse to work with dynamic scaling governors on systems with many CPUs to avoid scalability issues with it (Rafael Wysocki). - Fix the intel_pstate driver to report different maximum CPU frequencies on systems where they really are different and to ignore the turbo active ratio if hardware-managend P-states (HWP) are in use; make it use the match_string() helper (Xie Yisheng, Srinivas Pandruvada). - Fix a minor deferred probe issue in the qcom-kryo cpufreq driver (Niklas Cassel). - Add a tracepoint for the tracking of frequency limits changes (from Andriod) to the cpufreq core (Ruchi Kandoi). - Fix a circular lock dependency between CPU hotplug and sysfs locking in the cpufreq core reported by lockdep (Waiman Long). - Avoid excessive error reports on driver registration failures in the ARM cpuidle driver (Sudeep Holla). - Add a new device links flag to the driver core to make links go away automatically on supplier driver removal (Vivek Gautam). - Eliminate potential race condition between system-wide power management transitions and system shutdown (Pingfan Liu). - Add a quirk to save NVS memory on system suspend for the ASUS 1025C laptop (Willy Tarreau). - Make more systems use suspend-to-idle (instead of ACPI S3) by default (Tristian Celestin). - Get rid of stack VLA usage in the low-level hibernation code on 64-bit x86 (Kees Cook). - Fix error handling in the hibernation core and mark an expected fall-through switch in it (Chengguang Xu, Gustavo Silva). - Extend the generic power domains (genpd) framework to support attaching a device to a power domain by name (Ulf Hansson). - Fix device reference counting and user limits initialization in the devfreq core (Arvind Yadav, Matthias Kaehlcke). - Fix a few issues in the rk3399_dmc devfreq driver and improve its documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner). - Drop a redundant error message from the exynos-ppmu devfreq driver (Markus Elfring). -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJbcqOqAAoJEILEb/54YlRxOxMP/2ZFvnXU0pey/VX/+TelLMS7 /ROVGQ+s75QP1c9P/3BjvnXc0dsMRLRFPog+7wyoG/2DbEIV25COyAYsmSE0TRni XUaZO6YAx4/e3pm2AfamYbLCPvjw85eucHg5QJQ4b1mSVRNJOsNv+fUo6lmxwvnm j9kHvfttFeIhoa/3wa7hbhPKLln46atnpVSxCIceY7L5EFNhkKBvQt6B5yx9geb9 QMY6ohgkyN+bnK9QySXX+trcWpzx1uGX0apI07NkX7n9QGFdU4lCW8lsAf8jMC3g PPValTsUQsdRONUJJsrgqBioq4tvtgQWibyS2tfRrOGXYvHpJNpGmHVplfsrf/SE cvlsciR47YbmrXZuqg/r8hql+qefNN16/rnZIZ9VnbcG806VBy2z8IzI5wcdWR7p vzxhbCqVqOHcEdEwRwvuM2io67MWvkGtKsbCP+33DBh8SubpsECpKN4nIDboa3SE CJ15RUqXnF6enmmfCKOoHZeu7iXWDz6Pi71XmRzaj9DqbITVV281IerqLgV3rbal BVa53+202iD0IP+2b7KedGe/5ALlI97ffN0gB+L/eB832853DKSZQKzcvvpRhEN7 Iv2crnUwuQED9ns8P7hzp1Bk9CFCAOLW8UM43YwZRPWnmdeSsPJusJ5lzkAf7bss wfsFoUE3RaY4msnuHyCh =kv2M -----END PGP SIGNATURE----- Merge tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These add a new framework for CPU idle time injection, to be used by all of the idle injection code in the kernel in the future, fix some issues and add a number of relatively small extensions in multiple places. Specifics: - Add a new framework for CPU idle time injection (Daniel Lezcano). - Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT). - Add support for current CPU frequency reporting to the ACPI CPPC cpufreq driver (George Cherian). - Rework the cooling device registration in the imx6q/thermal driver (Bastian Stender). - Make the pcc-cpufreq driver refuse to work with dynamic scaling governors on systems with many CPUs to avoid scalability issues with it (Rafael Wysocki). - Fix the intel_pstate driver to report different maximum CPU frequencies on systems where they really are different and to ignore the turbo active ratio if hardware-managend P-states (HWP) are in use; make it use the match_string() helper (Xie Yisheng, Srinivas Pandruvada). - Fix a minor deferred probe issue in the qcom-kryo cpufreq driver (Niklas Cassel). - Add a tracepoint for the tracking of frequency limits changes (from Andriod) to the cpufreq core (Ruchi Kandoi). - Fix a circular lock dependency between CPU hotplug and sysfs locking in the cpufreq core reported by lockdep (Waiman Long). - Avoid excessive error reports on driver registration failures in the ARM cpuidle driver (Sudeep Holla). - Add a new device links flag to the driver core to make links go away automatically on supplier driver removal (Vivek Gautam). - Eliminate potential race condition between system-wide power management transitions and system shutdown (Pingfan Liu). - Add a quirk to save NVS memory on system suspend for the ASUS 1025C laptop (Willy Tarreau). - Make more systems use suspend-to-idle (instead of ACPI S3) by default (Tristian Celestin). - Get rid of stack VLA usage in the low-level hibernation code on 64-bit x86 (Kees Cook). - Fix error handling in the hibernation core and mark an expected fall-through switch in it (Chengguang Xu, Gustavo Silva). - Extend the generic power domains (genpd) framework to support attaching a device to a power domain by name (Ulf Hansson). - Fix device reference counting and user limits initialization in the devfreq core (Arvind Yadav, Matthias Kaehlcke). - Fix a few issues in the rk3399_dmc devfreq driver and improve its documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner). - Drop a redundant error message from the exynos-ppmu devfreq driver (Markus Elfring)" * tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (35 commits) PM / reboot: Eliminate race between reboot and suspend PM / hibernate: Mark expected switch fall-through cpufreq: intel_pstate: Ignore turbo active ratio in HWP cpufreq: Fix a circular lock dependency problem cpu/hotplug: Add a cpus_read_trylock() function x86/power/hibernate_64: Remove VLA usage cpufreq: trace frequency limits change cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP cpufreq: pcc-cpufreq: Disable dynamic scaling on many-CPU systems cpufreq: qcom-kryo: Silently error out on EPROBE_DEFER cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC cpufreq: armada-37xx: Add AVS support dt-bindings: marvell: Add documentation for the Armada 3700 AVS binding PM / devfreq: rk3399_dmc: Fix duplicated opp table on reload. PM / devfreq: Init user limits from OPP limits, not viceversa PM / devfreq: rk3399_dmc: fix spelling mistakes. PM / devfreq: rk3399_dmc: do not print error when get supply and clk defer. dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional. PM / devfreq: rk3399_dmc: remove wait for dcf irq event. dt-bindings: clock: add rk3399 DDR3 standard speed bins. ... |
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Rafael J. Wysocki | 17bc3432e3 |
Merge branches 'pm-core', 'pm-domains', 'pm-sleep', 'acpi-pm' and 'pm-cpuidle'
Merge changes in the PM core, system-wide PM infrastructure, generic power domains (genpd) framework, ACPI PM infrastructure and cpuidle for 4.19. * pm-core: driver core: Add flag to autoremove device link on supplier unbind driver core: Rename flag AUTOREMOVE to AUTOREMOVE_CONSUMER * pm-domains: PM / Domains: Introduce dev_pm_domain_attach_by_name() PM / Domains: Introduce option to attach a device by name to genpd PM / Domains: dt: Add a power-domain-names property * pm-sleep: PM / reboot: Eliminate race between reboot and suspend PM / hibernate: Mark expected switch fall-through x86/power/hibernate_64: Remove VLA usage PM / hibernate: cast PAGE_SIZE to int when comparing with error code * acpi-pm: ACPI / PM: save NVS memory for ASUS 1025C laptop ACPI / PM: Default to s2idle in all machines supporting LP S0 * pm-cpuidle: ARM: cpuidle: silence error on driver registration failure |
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Pingfan Liu | 55f2503c3b |
PM / reboot: Eliminate race between reboot and suspend
At present, "systemctl suspend" and "shutdown" can run in parrallel. A system can suspend after devices_shutdown(), and resume. Then the shutdown task goes on to power off. This causes many devices are not really shut off. Hence replacing reboot_mutex with system_transition_mutex (renamed from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as system_transition_mutex can be better to reflect the purpose of the mutex. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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Dave Hansen | 0d83432811 |
mm: Allow non-direct-map arguments to free_reserved_area()
free_reserved_area() takes pointers as arguments to show which addresses should be freed. However, it does this in a somewhat ambiguous way. If it gets a kernel direct map address, it always works. However, if it gets an address that is part of the kernel image alias mapping, it can fail. It fails if all of the following happen: * The specified address is part of the kernel image alias * Poisoning is requested (forcing a memset()) * The address is in a read-only portion of the kernel image The memset() fails on the read-only mapping, of course. free_reserved_area() *is* called both on the direct map and on kernel image alias addresses. We've just lucked out thus far that the kernel image alias areas it gets used on are read-write. I'm fairly sure this has been just a happy accident. It is quite easy to make free_reserved_area() work for all cases: just convert the address to a direct map address before doing the memset(), and do this unconditionally. There is little chance of a regression here because we previously did a virt_to_page() on the address for the memset, so we know these are not highmem pages for which virt_to_page() would fail. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: keescook@google.com Cc: aarcange@redhat.com Cc: jgross@suse.com Cc: jpoimboe@redhat.com Cc: gregkh@linuxfoundation.org Cc: peterz@infradead.org Cc: hughd@google.com Cc: torvalds@linux-foundation.org Cc: bp@alien8.de Cc: luto@kernel.org Cc: ak@linux.intel.com Cc: Kees Cook <keescook@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/20180802225826.1287AE3E@viggo.jf.intel.com |
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Pavel Tatashin | d1b47a7c9e |
mm: don't do zero_resv_unavail if memmap is not allocated
Moving zero_resv_unavail before memmap_init_zone(), caused a regression on
x86-32.
The cause is that we access struct pages before they are allocated when
CONFIG_FLAT_NODE_MEM_MAP is used.
free_area_init_nodes()
zero_resv_unavail()
mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced
free_area_init_node()
if CONFIG_FLAT_NODE_MEM_MAP
alloc_node_mem_map()
memblock_virt_alloc_node_nopanic() <- struct page alloced here
On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory
that it returns, so we do not need to do zero_resv_unavail() here.
Fixes:
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Pavel Tatashin | e181ae0c5d |
mm: zero unavailable pages before memmap init
We must zero struct pages for memory that is not backed by physical memory, or kernel does not have access to. Recently, there was a change which zeroed all memmap for all holes in e820. Unfortunately, it introduced a bug that is discussed here: https://www.spinics.net/lists/linux-mm/msg156764.html Linus, also saw this bug on his machine, and confirmed that reverting commit |
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Joe Perches | 0825a6f986 |
mm: use octal not symbolic permissions
mm/*.c files use symbolic and octal styles for permissions. Using octal and not symbolic permissions is preferred by many as more readable. https://lkml.org/lkml/2016/8/2/1945 Prefer the direct use of octal for permissions. Done using $ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c and some typing. Before: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l 44 After: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l 86 Miscellanea: o Whitespace neatening around these conversions. Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 7810e6781e |
mm, page_alloc: do not break __GFP_THISNODE by zonelist reset
In __alloc_pages_slowpath() we reset zonelist and preferred_zoneref for allocations that can ignore memory policies. The zonelist is obtained from current CPU's node. This is a problem for __GFP_THISNODE allocations that want to allocate on a different node, e.g. because the allocating thread has been migrated to a different CPU. This has been observed to break SLAB in our 4.4-based kernel, because there it relies on __GFP_THISNODE working as intended. If a slab page is put on wrong node's list, then further list manipulations may corrupt the list because page_to_nid() is used to determine which node's list_lock should be locked and thus we may take a wrong lock and race. Current SLAB implementation seems to be immune by luck thanks to commit |
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Matthew Wilcox | 4da1984edb |
mm: combine LRU and main union in struct page
This gives us five words of space in a single union in struct page. The compound_mapcount moves position (from offset 24 to offset 20) on 64-bit systems, but that does not seem likely to cause any trouble. Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Matthew Wilcox | fa3015b7ee |
mm: use page->deferred_list
Now that we can represent the location of 'deferred_list' in C instead of comments, make use of that ability. Link: http://lkml.kernel.org/r/20180518194519.3820-9-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Matthew Wilcox | 6e292b9be7 |
mm: split page_type out from _mapcount
We're already using a union of many fields here, so stop abusing the _mapcount and make page_type its own field. That implies renaming some of the machinery that creates PageBuddy, PageBalloon and PageKmemcg; bring back the PG_buddy, PG_balloon and PG_kmemcg names. As suggested by Kirill, make page_type a bitmask. Because it starts out life as -1 (thanks to sharing the storage with _mapcount), setting a page flag means clearing the appropriate bit. This gives us space for probably twenty or so extra bits (depending how paranoid we want to be about _mapcount underflow). Link: http://lkml.kernel.org/r/20180518194519.3820-3-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Huaisheng Ye | a380b40abb |
mm/page_alloc.c: remove useless parameter of finalise_ac()
finalise_ac() has parameter order which is not used at all. Remove it. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mathieu Malaterre | fb52bbaee5 |
mm: move is_pageblock_removable_nolock() to mm/memory_hotplug.c
is_pageblock_removable_nolock() is not used outside of mm/memory_hotplug.c. Move it next to unique caller is_mem_section_removable() and make it static. Remove prototype in <linux/memory_hotplug.h> to silence gcc warning (W=1): mm/page_alloc.c:7704:6: warning: no previous prototype for `is_pageblock_removable_nolock' [-Wmissing-prototypes] Link: http://lkml.kernel.org/r/20180509190001.24789-1-malat@debian.org Signed-off-by: Mathieu Malaterre <malat@debian.org> Suggested-by: Michal Hocko <mhocko@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Omar Sandoval | 93781325da |
lockdep: fix fs_reclaim annotation
While revisiting my Btrfs swapfile series [1], I introduced a situation
in which reclaim would lock i_rwsem, and even though the swapon() path
clearly made GFP_KERNEL allocations while holding i_rwsem, I got no
complaints from lockdep. It turns out that the rework of the fs_reclaim
annotation was broken: if the current task has PF_MEMALLOC set, we don't
acquire the dummy fs_reclaim lock, but when reclaiming we always check
this _after_ we've just set the PF_MEMALLOC flag. In most cases, we can
fix this by moving the fs_reclaim_{acquire,release}() outside of the
memalloc_noreclaim_{save,restore}(), althought kswapd is slightly
different. After applying this, I got the expected lockdep splats.
1: https://lwn.net/Articles/625412/
Link: http://lkml.kernel.org/r/9f8aa70652a98e98d7c4de0fc96a4addcee13efe.1523778026.git.osandov@fb.com
Fixes:
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Wei Yang | e69438596b |
mm/page_alloc: remove realsize in free_area_init_core()
Highmem's realsize always equals to freesize, so it is not necessary to spare a variable to record this. Link: http://lkml.kernel.org/r/20180413083859.65888-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 15c30bc090 |
mm, memory_hotplug: make has_unmovable_pages more robust
Oscar has reported:
: Due to an unfortunate setting with movablecore, memblocks containing bootmem
: memory (pages marked by get_page_bootmem()) ended up marked in zone_movable.
: So while trying to remove that memory, the system failed in do_migrate_range
: and __offline_pages never returned.
:
: This can be reproduced by running
: qemu-system-x86_64 -m 6G,slots=8,maxmem=8G -numa node,mem=4096M -numa node,mem=2048M
: and movablecore=4G kernel command line
:
: linux kernel: BIOS-provided physical RAM map:
: linux kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
: linux kernel: BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable
: linux kernel: BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000100000000-0x00000001bfffffff] usable
: linux kernel: NX (Execute Disable) protection: active
: linux kernel: SMBIOS 2.8 present.
: linux kernel: DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org
: linux kernel: Hypervisor detected: KVM
: linux kernel: e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
: linux kernel: e820: remove [mem 0x000a0000-0x000fffff] usable
: linux kernel: last_pfn = 0x1c0000 max_arch_pfn = 0x400000000
:
: linux kernel: SRAT: PXM 0 -> APIC 0x00 -> Node 0
: linux kernel: SRAT: PXM 1 -> APIC 0x01 -> Node 1
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x13fffffff]
: linux kernel: ACPI: SRAT: Node 1 PXM 1 [mem 0x140000000-0x1bfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x1c0000000-0x43fffffff] hotplug
: linux kernel: NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x0
: linux kernel: NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x13fffffff] -> [mem 0
: linux kernel: NODE_DATA(0) allocated [mem 0x13ffd6000-0x13fffffff]
: linux kernel: NODE_DATA(1) allocated [mem 0x1bffd3000-0x1bfffcfff]
:
: zoneinfo shows that the zone movable is placed into both numa nodes:
: Node 0, zone Movable
: pages free 160140
: min 1823
: low 2278
: high 2733
: spanned 262144
: present 262144
: managed 245670
: Node 1, zone Movable
: pages free 448427
: min 3827
: low 4783
: high 5739
: spanned 524288
: present 524288
: managed 515766
Note how only Node 0 has a hutplugable memory region which would rule it
out from the early memblock allocations (most likely memmap). Node1
will surely contain memmaps on the same node and those would prevent
offlining to succeed. So this is arguably a configuration issue.
Although one could argue that we should be more clever and rule early
allocations from the zone movable. This would be correct but probably
not worth the effort considering what a hack movablecore is.
Anyway, We could do better for those cases though. We rely on
start_isolate_page_range resp. has_unmovable_pages to do their job.
The first one isolates the whole range to be offlined so that we do not
allocate from it anymore and the later makes sure we are not stumbling
over non-migrateable pages.
has_unmovable_pages is overly optimistic, however. It doesn't check all
the pages if we are withing zone_movable because we rely that those
pages will be always migrateable. As it turns out we are still not
perfect there. While bootmem pages in zonemovable sound like a clear
bug which should be fixed let's remove the optimization for now and warn
if we encounter unmovable pages in zone_movable in the meantime. That
should help for now at least.
Btw. this wasn't a real problem until commit
|
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Joonsoo Kim | d883c6cf3b |
Revert "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE"
This reverts the following commits that change CMA design in MM. |
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Pavel Tatashin | 6f84f8d158 |
xen, mm: allow deferred page initialization for xen pv domains
Juergen Gross noticed that commit
|
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Joonsoo Kim | 1d47a3ec09 |
mm/cma: remove ALLOC_CMA
Now, all reserved pages for CMA region are belong to the ZONE_MOVABLE and it only serves for a request with GFP_HIGHMEM && GFP_MOVABLE. Therefore, we don't need to maintain ALLOC_CMA at all. Link: http://lkml.kernel.org/r/1512114786-5085-3-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim | bad8c6c0b1 |
mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE
Patch series "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE", v2. 0. History This patchset is the follow-up of the discussion about the "Introduce ZONE_CMA (v7)" [1]. Please reference it if more information is needed. 1. What does this patch do? This patch changes the management way for the memory of the CMA area in the MM subsystem. Currently the memory of the CMA area is managed by the zone where their pfn is belong to. However, this approach has some problems since MM subsystem doesn't have enough logic to handle the situation that different characteristic memories are in a single zone. To solve this issue, this patch try to manage all the memory of the CMA area by using the MOVABLE zone. In MM subsystem's point of view, characteristic of the memory on the MOVABLE zone and the memory of the CMA area are the same. So, managing the memory of the CMA area by using the MOVABLE zone will not have any problem. 2. Motivation There are some problems with current approach. See following. Although these problem would not be inherent and it could be fixed without this conception change, it requires many hooks addition in various code path and it would be intrusive to core MM and would be really error-prone. Therefore, I try to solve them with this new approach. Anyway, following is the problems of the current implementation. o CMA memory utilization First, following is the freepage calculation logic in MM. - For movable allocation: freepage = total freepage - For unmovable allocation: freepage = total freepage - CMA freepage Freepages on the CMA area is used after the normal freepages in the zone where the memory of the CMA area is belong to are exhausted. At that moment that the number of the normal freepages is zero, so - For movable allocation: freepage = total freepage = CMA freepage - For unmovable allocation: freepage = 0 If unmovable allocation comes at this moment, allocation request would fail to pass the watermark check and reclaim is started. After reclaim, there would exist the normal freepages so freepages on the CMA areas would not be used. FYI, there is another attempt [2] trying to solve this problem in lkml. And, as far as I know, Qualcomm also has out-of-tree solution for this problem. Useless reclaim: There is no logic to distinguish CMA pages in the reclaim path. Hence, CMA page is reclaimed even if the system just needs the page that can be usable for the kernel allocation. Atomic allocation failure: This is also related to the fallback allocation policy for the memory of the CMA area. Consider the situation that the number of the normal freepages is *zero* since the bunch of the movable allocation requests come. Kswapd would not be woken up due to following freepage calculation logic. - For movable allocation: freepage = total freepage = CMA freepage If atomic unmovable allocation request comes at this moment, it would fails due to following logic. - For unmovable allocation: freepage = total freepage - CMA freepage = 0 It was reported by Aneesh [3]. Useless compaction: Usual high-order allocation request is unmovable allocation request and it cannot be served from the memory of the CMA area. In compaction, migration scanner try to migrate the page in the CMA area and make high-order page there. As mentioned above, it cannot be usable for the unmovable allocation request so it's just waste. 3. Current approach and new approach Current approach is that the memory of the CMA area is managed by the zone where their pfn is belong to. However, these memory should be distinguishable since they have a strong limitation. So, they are marked as MIGRATE_CMA in pageblock flag and handled specially. However, as mentioned in section 2, the MM subsystem doesn't have enough logic to deal with this special pageblock so many problems raised. New approach is that the memory of the CMA area is managed by the MOVABLE zone. MM already have enough logic to deal with special zone like as HIGHMEM and MOVABLE zone. So, managing the memory of the CMA area by the MOVABLE zone just naturally work well because constraints for the memory of the CMA area that the memory should always be migratable is the same with the constraint for the MOVABLE zone. There is one side-effect for the usability of the memory of the CMA area. The use of MOVABLE zone is only allowed for a request with GFP_HIGHMEM && GFP_MOVABLE so now the memory of the CMA area is also only allowed for this gfp flag. Before this patchset, a request with GFP_MOVABLE can use them. IMO, It would not be a big issue since most of GFP_MOVABLE request also has GFP_HIGHMEM flag. For example, file cache page and anonymous page. However, file cache page for blockdev file is an exception. Request for it has no GFP_HIGHMEM flag. There is pros and cons on this exception. In my experience, blockdev file cache pages are one of the top reason that causes cma_alloc() to fail temporarily. So, we can get more guarantee of cma_alloc() success by discarding this case. Note that there is no change in admin POV since this patchset is just for internal implementation change in MM subsystem. Just one minor difference for admin is that the memory stat for CMA area will be printed in the MOVABLE zone. That's all. 4. Result Following is the experimental result related to utilization problem. 8 CPUs, 1024 MB, VIRTUAL MACHINE make -j16 <Before> CMA area: 0 MB 512 MB Elapsed-time: 92.4 186.5 pswpin: 82 18647 pswpout: 160 69839 <After> CMA : 0 MB 512 MB Elapsed-time: 93.1 93.4 pswpin: 84 46 pswpout: 183 92 akpm: "kernel test robot" reported a 26% improvement in vm-scalability.throughput: http://lkml.kernel.org/r/20180330012721.GA3845@yexl-desktop [1]: lkml.kernel.org/r/1491880640-9944-1-git-send-email-iamjoonsoo.kim@lge.com [2]: https://lkml.org/lkml/2014/10/15/623 [3]: http://www.spinics.net/lists/linux-mm/msg100562.html Link: http://lkml.kernel.org/r/1512114786-5085-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim | d3cda2337b |
mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request
Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that important to reserve. When ZONE_MOVABLE is used, this problem would theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE allocation request which is mainly used for page cache and anon page allocation. So, fix it by setting 0 to sysctl_lowmem_reserve_ratio[ZONE_HIGHMEM]. And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size makes code complex. For example, if there is highmem system, following reserve ratio is activated for *NORMAL ZONE* which would be easyily misleading people. #ifdef CONFIG_HIGHMEM 32 #endif This patch also fixes this situation by defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES and place "#ifdef" to right place. Link: http://lkml.kernel.org/r/1504672525-17915-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Tony Lindgren <tony@atomide.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Roman Gushchin | 034ebf65c3 |
mm: treat indirectly reclaimable memory as available in MemAvailable
Adjust /proc/meminfo MemAvailable calculation by adding the amount of indirectly reclaimable memory (rounded to the PAGE_SIZE). Link: http://lkml.kernel.org/r/20180305133743.12746-4-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Kravetz | 2c7452a075 |
mm/page_isolation.c: make start_isolate_page_range() fail if already isolated
start_isolate_page_range() is used to set the migrate type of a set of pageblocks to MIGRATE_ISOLATE while attempting to start a migration operation. It assumes that only one thread is calling it for the specified range. This routine is used by CMA, memory hotplug and gigantic huge pages. Each of these users synchronize access to the range within their subsystem. However, two subsystems (CMA and gigantic huge pages for example) could attempt operations on the same range. If this happens, one thread may 'undo' the work another thread is doing. This can result in pageblocks being incorrectly left marked as MIGRATE_ISOLATE and therefore not available for page allocation. What is ideally needed is a way to synchronize access to a set of pageblocks that are undergoing isolation and migration. The only thing we know about these pageblocks is that they are all in the same zone. A per-node mutex is too coarse as we want to allow multiple operations on different ranges within the same zone concurrently. Instead, we will use the migration type of the pageblocks themselves as a form of synchronization. start_isolate_page_range sets the migration type on a set of page- blocks going in order from the one associated with the smallest pfn to the largest pfn. The zone lock is acquired to check and set the migration type. When going through the list of pageblocks check if MIGRATE_ISOLATE is already set. If so, this indicates another thread is working on this pageblock. We know exactly which pageblocks we set, so clean up by undo those and return -EBUSY. This allows start_isolate_page_range to serve as a synchronization mechanism and will allow for more general use of callers making use of these interfaces. Update comments in alloc_contig_range to reflect this new functionality. Each CPU holds the associated zone lock to modify or examine the migration type of a pageblock. And, it will only examine/update a single pageblock per lock acquire/release cycle. Link: http://lkml.kernel.org/r/20180309224731.16978-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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David Rientjes | 5ecd9d403a |
mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory
Kswapd will not wakeup if per-zone watermarks are not failing or if too many previous attempts at background reclaim have failed. This can be true if there is a lot of free memory available. For high- order allocations, kswapd is responsible for waking up kcompactd for background compaction. If the zone is not below its watermarks or reclaim has recently failed (lots of free memory, nothing left to reclaim), kcompactd does not get woken up. When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be woken up even if kswapd will not reclaim. This allows high-order allocations, such as thp, to still trigger background compaction even when the zone has an abundance of free memory. Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803111659420.209721@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aaron Lu | 97334162e4 |
mm/free_pcppages_bulk: prefetch buddy while not holding lock
When a page is freed back to the global pool, its buddy will be checked
to see if it's possible to do a merge. This requires accessing buddy's
page structure and that access could take a long time if it's cache
cold.
This patch adds a prefetch to the to-be-freed page's buddy outside of
zone->lock in hope of accessing buddy's page structure later under
zone->lock will be faster. Since we *always* do buddy merging and check
an order-0 page's buddy to try to merge it when it goes into the main
allocator, the cacheline will always come in, i.e. the prefetched data
will never be unused.
Normally, the number of prefetch will be pcp->batch(default=31 and has
an upper limit of (PAGE_SHIFT * 8)=96 on x86_64) but in the case of
pcp's pages get all drained, it will be pcp->count which has an upper
limit of pcp->high. pcp->high, although has a default value of 186
(pcp->batch=31 * 6), can be changed by user through
/proc/sys/vm/percpu_pagelist_fraction and there is no software upper
limit so could be large, like several thousand. For this reason, only
the first pcp->batch number of page's buddy structure is prefetched to
avoid excessive prefetching.
In the meantime, there are two concerns:
1. the prefetch could potentially evict existing cachelines, especially
for L1D cache since it is not huge
2. there is some additional instruction overhead, namely calculating
buddy pfn twice
For 1, it's hard to say, this microbenchmark though shows good result
but the actual benefit of this patch will be workload/CPU dependant;
For 2, since the calculation is a XOR on two local variables, it's
expected in many cases that cycles spent will be offset by reduced
memory latency later. This is especially true for NUMA machines where
multiple CPUs are contending on zone->lock and the most time consuming
part under zone->lock is the wait of 'struct page' cacheline of the
to-be-freed pages and their buddies.
Test with will-it-scale/page_fault1 full load:
kernel Broadwell(2S) Skylake(2S) Broadwell(4S) Skylake(4S)
v4.16-rc2+ 9034215 7971818 13667135 15677465
patch2/3
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Aaron Lu | 0a5f4e5b45 |
mm/free_pcppages_bulk: do not hold lock when picking pages to free
When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, the
zone->lock is held and then pages are chosen from PCP's migratetype
list. While there is actually no need to do this 'choose part' under
lock since it's PCP pages, the only CPU that can touch them is us and
irq is also disabled.
Moving this part outside could reduce lock held time and improve
performance. Test with will-it-scale/page_fault1 full load:
kernel Broadwell(2S) Skylake(2S) Broadwell(4S) Skylake(4S)
v4.16-rc2+ 9034215 7971818 13667135 15677465
this patch
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Aaron Lu | 77ba9062e4 |
mm/free_pcppages_bulk: update pcp->count inside
Matthew Wilcox found that all callers of free_pcppages_bulk() currently update pcp->count immediately after so it's natural to do it inside free_pcppages_bulk(). No functionality or performance change is expected from this patch. Link: http://lkml.kernel.org/r/20180301062845.26038-2-aaron.lu@intel.com Signed-off-by: Aaron Lu <aaron.lu@intel.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Huang Ying <ying.huang@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kemi Wang <kemi.wang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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David Rientjes | 7f16f91fdf |
mm, page_alloc: move mirrored_kernelcore to __meminitdata
mirrored_kernelcore can be in __meminitdata, so move it there. At the same time, fixup section specifiers to be after the name of the variable per checkpatch. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802121623280.179479@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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David Rientjes | a5c6d65093 |
mm, page_alloc: extend kernelcore and movablecore for percent
Both kernelcore= and movablecore= can be used to define the amount of ZONE_NORMAL and ZONE_MOVABLE on a system, respectively. This requires the system memory capacity to be known when specifying the command line, however. This introduces the ability to define both kernelcore= and movablecore= as a percentage of total system memory. This is convenient for systems software that wants to define the amount of ZONE_MOVABLE, for example, as a proportion of a system's memory rather than a hardcoded byte value. To define the percentage, the final character of the parameter should be a '%'. mhocko: "why is anyone using these options nowadays?" rientjes: : : Fragmentation of non-__GFP_MOVABLE pages due to low on memory : situations can pollute most pageblocks on the system, as much as 1GB of : slab being fragmented over 128GB of memory, for example. When the : amount of kernel memory is well bounded for certain systems, it is : better to aggressively reclaim from existing MIGRATE_UNMOVABLE : pageblocks rather than eagerly fallback to others. : : We have additional patches that help with this fragmentation if you're : interested, specifically kcompactd compaction of MIGRATE_UNMOVABLE : pageblocks triggered by fallback of non-__GFP_MOVABLE allocations and : draining of pcp lists back to the zone free area to prevent stranding. [rientjes@google.com: updates] Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802131700160.71590@chino.kir.corp.google.com Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802121622470.179479@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | d0dc12e86b |
mm/memory_hotplug: optimize memory hotplug
During memory hotplugging we traverse struct pages three times: 1. memset(0) in sparse_add_one_section() 2. loop in __add_section() to set do: set_page_node(page, nid); and SetPageReserved(page); 3. loop in memmap_init_zone() to call __init_single_pfn() This patch removes the first two loops, and leaves only loop 3. All struct pages are initialized in one place, the same as it is done during boot. The benefits: - We improve memory hotplug performance because we are not evicting the cache several times and also reduce loop branching overhead. - Remove condition from hotpath in __init_single_pfn(), that was added in order to fix the problem that was reported by Bharata in the above email thread, thus also improve performance during normal boot. - Make memory hotplug more similar to the boot memory initialization path because we zero and initialize struct pages only in one function. - Simplifies memory hotplug struct page initialization code, and thus enables future improvements, such as multi-threading the initialization of struct pages in order to improve hotplug performance even further on larger machines. [pasha.tatashin@oracle.com: v5] Link: http://lkml.kernel.org/r/20180228030308.1116-7-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180215165920.8570-7-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Baoquan He <bhe@redhat.com> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | c9e97a1997 |
mm: initialize pages on demand during boot
Deferred page initialization allows the boot cpu to initialize a small subset of the system's pages early in boot, with other cpus doing the rest later on. It is, however, problematic to know how many pages the kernel needs during boot. Different modules and kernel parameters may change the requirement, so the boot cpu either initializes too many pages or runs out of memory. To fix that, initialize early pages on demand. This ensures the kernel does the minimum amount of work to initialize pages during boot and leaves the rest to be divided in the multithreaded initialization path (deferred_init_memmap). The on-demand code is permanently disabled using static branching once deferred pages are initialized. After the static branch is changed to false, the overhead is up-to two branch-always instructions if the zone watermark check fails or if rmqueue fails. Sergey Senozhatsky noticed that while deferred pages currently make sense only on NUMA machines (we start one thread per latency node), CONFIG_NUMA is not a requirement for CONFIG_DEFERRED_STRUCT_PAGE_INIT, so that is also must be addressed in the patch. [akpm@linux-foundation.org: fix typo in comment, make deferred_pages static] [pasha.tatashin@oracle.com: fix min() type mismatch warning] Link: http://lkml.kernel.org/r/20180212164543.26592-1-pasha.tatashin@oracle.com [pasha.tatashin@oracle.com: use zone_to_nid() in deferred_grow_zone()] Link: http://lkml.kernel.org/r/20180214163343.21234-2-pasha.tatashin@oracle.com [pasha.tatashin@oracle.com: might_sleep warning] Link: http://lkml.kernel.org/r/20180306192022.28289-1-pasha.tatashin@oracle.com [akpm@linux-foundation.org: s/spin_lock/spin_lock_irq/ in page_alloc_init_late()] [pasha.tatashin@oracle.com: v5] Link: http://lkml.kernel.org/r/20180309220807.24961-3-pasha.tatashin@oracle.com [akpm@linux-foundation.org: tweak comments] [pasha.tatashin@oracle.com: v6] Link: http://lkml.kernel.org/r/20180313182355.17669-3-pasha.tatashin@oracle.com [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20180209192216.20509-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | 3a2d7fa8a3 |
mm: disable interrupts while initializing deferred pages
Vlastimil Babka reported about a window issue during which when deferred pages are initialized, and the current version of on-demand initialization is finished, allocations may fail. While this is highly unlikely scenario, since this kind of allocation request must be large, and must come from interrupt handler, we still want to cover it. We solve this by initializing deferred pages with interrupts disabled, and holding node_size_lock spin lock while pages in the node are being initialized. The on-demand deferred page initialization that comes later will use the same lock, and thus synchronize with deferred_init_memmap(). It is unlikely for threads that initialize deferred pages to be interrupted. They run soon after smp_init(), but before modules are initialized, and long before user space programs. This is why there is no adverse effect of having these threads running with interrupts disabled. [pasha.tatashin@oracle.com: v6] Link: http://lkml.kernel.org/r/20180313182355.17669-2-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180309220807.24961-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Anshuman Khandual | 310253514b |
mm/migrate: rename migration reason MR_CMA to MR_CONTIG_RANGE
alloc_contig_range() initiates compaction and eventual migration for the purpose of either CMA or HugeTLB allocations. At present, the reason code remains the same MR_CMA for either of these cases. Let's make it MR_CONTIG_RANGE which will appropriately reflect the reason code in both these cases. Link: http://lkml.kernel.org/r/20180202091518.18798-1-khandual@linux.vnet.ibm.com Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | f5a8eb632b |
arch: remove obsolete architecture ports
This removes the entire architecture code for blackfin, cris, frv, m32r, metag, mn10300, score, and tile, including the associated device drivers. I have been working with the (former) maintainers for each one to ensure that my interpretation was right and the code is definitely unused in mainline kernels. Many had fond memories of working on the respective ports to start with and getting them included in upstream, but also saw no point in keeping the port alive without any users. In the end, it seems that while the eight architectures are extremely different, they all suffered the same fate: There was one company in charge of an SoC line, a CPU microarchitecture and a software ecosystem, which was more costly than licensing newer off-the-shelf CPU cores from a third party (typically ARM, MIPS, or RISC-V). It seems that all the SoC product lines are still around, but have not used the custom CPU architectures for several years at this point. In contrast, CPU instruction sets that remain popular and have actively maintained kernel ports tend to all be used across multiple licensees. The removal came out of a discussion that is now documented at https://lwn.net/Articles/748074/. Unlike the original plans, I'm not marking any ports as deprecated but remove them all at once after I made sure that they are all unused. Some architectures (notably tile, mn10300, and blackfin) are still being shipped in products with old kernels, but those products will never be updated to newer kernel releases. After this series, we still have a few architectures without mainline gcc support: - unicore32 and hexagon both have very outdated gcc releases, but the maintainers promised to work on providing something newer. At least in case of hexagon, this will only be llvm, not gcc. - openrisc, risc-v and nds32 are still in the process of finishing their support or getting it added to mainline gcc in the first place. They all have patched gcc-7.3 ports that work to some degree, but complete upstream support won't happen before gcc-8.1. Csky posted their first kernel patch set last week, their situation will be similar. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJawdL2AAoJEGCrR//JCVInuH0P/RJAZh1nTD+TR34ZhJq2TBoo PgygwDU7Z2+tQVU+EZ453Gywz9/NMRFk1RWAZqrLix4ZtyIMvC6A1qfT2yH1Y7Fb Qh6tccQeLe4ezq5u4S/46R/fQXu3Txr92yVwzJJUuPyU0arF9rv5MmI8e6p7L1en yb74kSEaCe+/eMlsEj1Cc1dgthDNXGKIURHkRsILoweysCpesjiTg4qDcL+yTibV FP2wjVbniKESMKS6qL71tiT5sexvLsLwMNcGiHPj94qCIQuI7DLhLdBVsL5Su6gI sbtgv0dsq4auRYAbQdMaH1hFvu6WptsuttIbOMnz2Yegi2z28H8uVXkbk2WVLbqG ZESUwutGh8MzOL2RJ4jyyQq5sfo++CRGlfKjr6ImZRv03dv0pe/W85062cK5cKNs cgDDJjGRorOXW7dyU6jG2gRqODOQBObIv3w5efdq5OgzOWlbI4EC+Y5u1Z0JF/76 pSwtGXA6YhwC+9LLAlnVTHG+yOwuLmAICgoKcTbzTVDKA2YQZG/cYuQfI5S1wD8e X6urPx3Md2GCwLXQ9mzKBzKZUpu/Tuhx0NvwF4qVxy6x1PELjn68zuP7abDHr46r 57/09ooVN+iXXnEGMtQVS/OPvYHSa2NgTSZz6Y86lCRbZmUOOlK31RDNlMvYNA+s 3iIVHovno/JuJnTOE8LY =fQ8z -----END PGP SIGNATURE----- Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pul removal of obsolete architecture ports from Arnd Bergmann: "This removes the entire architecture code for blackfin, cris, frv, m32r, metag, mn10300, score, and tile, including the associated device drivers. I have been working with the (former) maintainers for each one to ensure that my interpretation was right and the code is definitely unused in mainline kernels. Many had fond memories of working on the respective ports to start with and getting them included in upstream, but also saw no point in keeping the port alive without any users. In the end, it seems that while the eight architectures are extremely different, they all suffered the same fate: There was one company in charge of an SoC line, a CPU microarchitecture and a software ecosystem, which was more costly than licensing newer off-the-shelf CPU cores from a third party (typically ARM, MIPS, or RISC-V). It seems that all the SoC product lines are still around, but have not used the custom CPU architectures for several years at this point. In contrast, CPU instruction sets that remain popular and have actively maintained kernel ports tend to all be used across multiple licensees. [ See the new nds32 port merged in the previous commit for the next generation of "one company in charge of an SoC line, a CPU microarchitecture and a software ecosystem" - Linus ] The removal came out of a discussion that is now documented at https://lwn.net/Articles/748074/. Unlike the original plans, I'm not marking any ports as deprecated but remove them all at once after I made sure that they are all unused. Some architectures (notably tile, mn10300, and blackfin) are still being shipped in products with old kernels, but those products will never be updated to newer kernel releases. After this series, we still have a few architectures without mainline gcc support: - unicore32 and hexagon both have very outdated gcc releases, but the maintainers promised to work on providing something newer. At least in case of hexagon, this will only be llvm, not gcc. - openrisc, risc-v and nds32 are still in the process of finishing their support or getting it added to mainline gcc in the first place. They all have patched gcc-7.3 ports that work to some degree, but complete upstream support won't happen before gcc-8.1. Csky posted their first kernel patch set last week, their situation will be similar [ Palmer Dabbelt points out that RISC-V support is in mainline gcc since gcc-7, although gcc-7.3.0 is the recommended minimum - Linus ]" This really says it all: 2498 files changed, 95 insertions(+), 467668 deletions(-) * tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits) MAINTAINERS: UNICORE32: Change email account staging: iio: remove iio-trig-bfin-timer driver tty: hvc: remove tile driver tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers serial: remove tile uart driver serial: remove m32r_sio driver serial: remove blackfin drivers serial: remove cris/etrax uart drivers usb: Remove Blackfin references in USB support usb: isp1362: remove blackfin arch glue usb: musb: remove blackfin port usb: host: remove tilegx platform glue pwm: remove pwm-bfin driver i2c: remove bfin-twi driver spi: remove blackfin related host drivers watchdog: remove bfin_wdt driver can: remove bfin_can driver mmc: remove bfin_sdh driver input: misc: remove blackfin rotary driver input: keyboard: remove bf54x driver ... |
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Daniel Vacek | f59f1caf72 |
Revert "mm: page_alloc: skip over regions of invalid pfns where possible"
This reverts commit |
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Tetsuo Handa | 2e517d6816 |
lockdep: fix fs_reclaim warning
Dave Jones reported fs_reclaim lockdep warnings. ============================================ WARNING: possible recursive locking detected 4.15.0-rc9-backup-debug+ #1 Not tainted -------------------------------------------- sshd/24800 is trying to acquire lock: (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30 but task is already holding lock: (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(fs_reclaim); lock(fs_reclaim); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by sshd/24800: #0: (sk_lock-AF_INET6){+.+.}, at: [<000000001a069652>] tcp_sendmsg+0x19/0x40 #1: (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30 stack backtrace: CPU: 3 PID: 24800 Comm: sshd Not tainted 4.15.0-rc9-backup-debug+ #1 Call Trace: dump_stack+0xbc/0x13f __lock_acquire+0xa09/0x2040 lock_acquire+0x12e/0x350 fs_reclaim_acquire.part.102+0x29/0x30 kmem_cache_alloc+0x3d/0x2c0 alloc_extent_state+0xa7/0x410 __clear_extent_bit+0x3ea/0x570 try_release_extent_mapping+0x21a/0x260 __btrfs_releasepage+0xb0/0x1c0 btrfs_releasepage+0x161/0x170 try_to_release_page+0x162/0x1c0 shrink_page_list+0x1d5a/0x2fb0 shrink_inactive_list+0x451/0x940 shrink_node_memcg.constprop.88+0x4c9/0x5e0 shrink_node+0x12d/0x260 try_to_free_pages+0x418/0xaf0 __alloc_pages_slowpath+0x976/0x1790 __alloc_pages_nodemask+0x52c/0x5c0 new_slab+0x374/0x3f0 ___slab_alloc.constprop.81+0x47e/0x5a0 __slab_alloc.constprop.80+0x32/0x60 __kmalloc_track_caller+0x267/0x310 __kmalloc_reserve.isra.40+0x29/0x80 __alloc_skb+0xee/0x390 sk_stream_alloc_skb+0xb8/0x340 tcp_sendmsg_locked+0x8e6/0x1d30 tcp_sendmsg+0x27/0x40 inet_sendmsg+0xd0/0x310 sock_write_iter+0x17a/0x240 __vfs_write+0x2ab/0x380 vfs_write+0xfb/0x260 SyS_write+0xb6/0x140 do_syscall_64+0x1e5/0xc05 entry_SYSCALL64_slow_path+0x25/0x25 This warning is caused by commit |
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Arnd Bergmann | 79375ea3ec |
mm: remove obsolete alloc_remap()
Tile was the only remaining architecture to implement alloc_remap(), and since that is being removed, there is no point in keeping this function. Removing all callers simplifies the mem_map handling. Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> |
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Ard Biesheuvel | 3e04040df6 |
Revert "mm/page_alloc: fix memmap_init_zone pageblock alignment"
This reverts commit |
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Daniel Vacek | 864b75f9d6 |
mm/page_alloc: fix memmap_init_zone pageblock alignment
Commit |
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Juergen Gross | 895f7b8e90 |
mm: don't defer struct page initialization for Xen pv guests
Commit |
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Linus Torvalds | 3ff1b28caa |
libnvdimm for 4.16
* Require struct page by default for filesystem DAX to remove a number of surprising failure cases. This includes failures with direct I/O, gdb and fork(2). * Add support for the new Platform Capabilities Structure added to the NFIT in ACPI 6.2a. This new table tells us whether the platform supports flushing of CPU and memory controller caches on unexpected power loss events. * Revamp vmem_altmap and dev_pagemap handling to clean up code and better support future future PCI P2P uses. * Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL spec, and instead rely on the generic ND_CMD_CALL approach used by the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}. * Enhance nfit_test so we can test some of the new things added in version 1.6 of the DSM specification. This includes testing firmware download and simulating the Last Shutdown State (LSS) status. -----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJaeOg0AAoJEJ/BjXdf9fLBAFoQAI/IgcgJ2h9lfEpgjBRTC44t 2p8dxwT1Ofw3Y1aR/tI8nYRXjRtAGuP4UIeRVnb1CL/N7PagJyoMGU+6hmzg+ptY c7cEDvw6nZOhrFwXx/xn7R53sYG8zH+UE6+jTR/PP/G4mQJfFCg4iF9R72Y7z0n7 aurf82Kz137NPUy6dNr4V9bmPMJWAaOci9WOj5SKddR5ZSNbjoxylTwQRvre5y4r 7HQTScEkirABOdSf1JoXTSUXCH/RC9UFFXR03ScHstGb1HjCj3KdcicVc50Q++Ub qsEudhE6i44PEW1Hh4Qkg6hjHMEa8qHP+ShBuRuVaUmlghYTQn66niJAYLZilwdz EVjE7vR+toHA5g3YCalEmYVutUEhIDkh/xfpd7vM6ZorUGJy95a2elEJs2fHBffC gEhnCip7FROPcK5RDNUM8hBgnG/q5wwWPQMKY+6rKDZQx3mXssCrKp2Vlx7kBwMG rpblkEpYjPonbLEHxsSU8yTg9Uq55ciIWgnOToffcjZvjbihi8WUVlHcwHUMPf/o DWElg+4qmG0Sdd4S2NeAGwTl1Ewrf2RrtUGMjHtH4OUFs1wo6ZmfrxFzzMfoZ1Od ko/s65v4uwtTzECh2o+XQaNsReR5YETXxmA40N/Jpo7/7twABIoZ/ASvj/3ZBYj+ sie+u2rTod8/gQWSfHpJ =MIMX -----END PGP SIGNATURE----- Merge tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Ross Zwisler: - Require struct page by default for filesystem DAX to remove a number of surprising failure cases. This includes failures with direct I/O, gdb and fork(2). - Add support for the new Platform Capabilities Structure added to the NFIT in ACPI 6.2a. This new table tells us whether the platform supports flushing of CPU and memory controller caches on unexpected power loss events. - Revamp vmem_altmap and dev_pagemap handling to clean up code and better support future future PCI P2P uses. - Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL spec, and instead rely on the generic ND_CMD_CALL approach used by the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}. - Enhance nfit_test so we can test some of the new things added in version 1.6 of the DSM specification. This includes testing firmware download and simulating the Last Shutdown State (LSS) status. * tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (37 commits) libnvdimm, namespace: remove redundant initialization of 'nd_mapping' acpi, nfit: fix register dimm error handling libnvdimm, namespace: make min namespace size 4K tools/testing/nvdimm: force nfit_test to depend on instrumented modules libnvdimm/nfit_test: adding support for unit testing enable LSS status libnvdimm/nfit_test: add firmware download emulation nfit-test: Add platform cap support from ACPI 6.2a to test libnvdimm: expose platform persistence attribute for nd_region acpi: nfit: add persistent memory control flag for nd_region acpi: nfit: Add support for detect platform CPU cache flush on power loss device-dax: Fix trailing semicolon libnvdimm, btt: fix uninitialized err_lock dax: require 'struct page' by default for filesystem dax ext2: auto disable dax instead of failing mount ext4: auto disable dax instead of failing mount mm, dax: introduce pfn_t_special() mm: Fix devm_memremap_pages() collision handling mm: Fix memory size alignment in devm_memremap_pages_release() memremap: merge find_dev_pagemap into get_dev_pagemap memremap: change devm_memremap_pages interface to use struct dev_pagemap ... |
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Ross Zwisler | ee95f4059a | Merge branch 'for-4.16/nfit' into libnvdimm-for-next | |
Michal Hocko | 9bb5a391f9 |
mm, memory_hotplug: fix memmap initialization
Bharata has noticed that onlining a newly added memory doesn't increase the total memory, pointing to commit |
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Shile Zhang | 3c2c648842 |
mm/page_alloc.c: fix typos in comments
Link: http://lkml.kernel.org/r/1515485774-4768-1-git-send-email-zhangshile@gmail.com Signed-off-by: Shile Zhang <zhangshile@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jiankang Chen | 48128397b0 |
mm/page_alloc.c: fix comment in __get_free_pages()
__get_free_pages() will return a virtual address, but it is not just a 32-bit address, for example on a 64-bit system. And this comment really confuses new readers of mm. Link: http://lkml.kernel.org/r/1511780964-64864-1-git-send-email-chenjiankang1@huawei.com Signed-off-by: Jiankang Chen <chenjiankang1@huawei.com> Reported-by: Hanjun Guo <guohanjun@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yisheng Xie <xieyisheng1@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | 80b1f41c09 |
mm: split deferred_init_range into initializing and freeing parts
In deferred_init_range() we initialize struct pages, and also free them to buddy allocator. We do it in separate loops, because buddy page is computed ahead, so we do not want to access a struct page that has not been initialized yet. There is still, however, a corner case where it is potentially possible to access uninitialized struct page: this is when buddy page is from the next memblock range. This patch fixes this problem by splitting deferred_init_range() into two functions: one to initialize struct pages, and another to free them. In addition, this patch brings the following improvements: - Get rid of __def_free() helper function. And simplifies loop logic by adding a new pfn validity check function: deferred_pfn_valid(). - Reduces number of variables that we track. So, there is a higher chance that we will avoid using stack to store/load variables inside hot loops. - Enables future multi-threading of these functions: do initialization in multiple threads, wait for all threads to finish, do freeing part in multithreading. Tested on x86 with 1T of memory to make sure no regressions are introduced. [akpm@linux-foundation.org: fix spello in comment] Link: http://lkml.kernel.org/r/20171107150446.32055-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Christoph Hellwig | a99583e780 |
mm: pass the vmem_altmap to memmap_init_zone
Pass the vmem_altmap two levels down instead of needing a lookup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
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Dave Young | e8c24773d6 |
mm: check pfn_valid first in zero_resv_unavail
With latest kernel I get below bug while testing kdump: BUG: unable to handle kernel paging request at ffffea00034b1040 IP: zero_resv_unavail+0xbd/0x126 PGD 37b98067 P4D 37b98067 PUD 37b97067 PMD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.15.0-rc1+ #316 Hardware name: LENOVO 20ARS1BJ02/20ARS1BJ02, BIOS GJET92WW (2.42 ) 03/03/2017 task: ffffffff81a0e4c0 task.stack: ffffffff81a00000 RIP: 0010:zero_resv_unavail+0xbd/0x126 RSP: 0000:ffffffff81a03d88 EFLAGS: 00010006 RAX: 0000000000000000 RBX: ffffea00034b1040 RCX: 0000000000000010 RDX: 0000000000000000 RSI: 0000000000000092 RDI: ffffea00034b1040 RBP: 00000000000d2c41 R08: 00000000000000c0 R09: 0000000000000a0d R10: 0000000000000002 R11: 0000000000007f01 R12: ffffffff81a03d90 R13: ffffea0000000000 R14: 0000000000000063 R15: 0000000000000062 FS: 0000000000000000(0000) GS:ffffffff81c73000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea00034b1040 CR3: 0000000037609000 CR4: 00000000000606b0 Call Trace: ? free_area_init_nodes+0x640/0x664 ? zone_sizes_init+0x58/0x72 ? setup_arch+0xb50/0xc6c ? start_kernel+0x64/0x43d ? secondary_startup_64+0xa5/0xb0 Code: c1 e8 0c 48 39 d8 76 27 48 89 de 48 c1 e3 06 48 c7 c7 7a 87 79 81 e8 b0 c0 3e ff 4c 01 eb b9 10 00 00 00 31 c0 48 89 df 49 ff c6 <f3> ab eb bc 6a 00 49 c7 c0 f0 93 d1 81 31 d2 83 ce ff 41 54 49 RIP: zero_resv_unavail+0xbd/0x126 RSP: ffffffff81a03d88 CR2: ffffea00034b1040 ---[ end trace f5ba9e8f73c7ee26 ]--- This is introduced by commit |
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Lucas Stach | c24ad77d96 |
mm/page_alloc.c: avoid excessive IRQ disabled times in free_unref_page_list()
Since commit |
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Mike Kravetz | 63cd448908 |
mm/cma: fix alloc_contig_range ret code/potential leak
If the call __alloc_contig_migrate_range() in alloc_contig_range returns
-EBUSY, processing continues so that test_pages_isolated() is called
where there is a tracepoint to identify the busy pages. However, it is
possible for busy pages to become available between the calls to these
two routines. In this case, the range of pages may be allocated.
Unfortunately, the original return code (ret == -EBUSY) is still set and
returned to the caller. Therefore, the caller believes the pages were
not allocated and they are leaked.
Update the comment to indicate that allocation is still possible even if
__alloc_contig_migrate_range returns -EBUSY. Also, clear return code in
this case so that it is not accidentally used or returned to caller.
Link: http://lkml.kernel.org/r/20171122185214.25285-1-mike.kravetz@oracle.com
Fixes:
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Michal Hocko | 4b81cb2ff6 |
mm, memory_hotplug: do not back off draining pcp free pages from kworker context
drain_all_pages backs off when called from a kworker context since commit |
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Vlastimil Babka | 2583d67132 |
mm, compaction: split off flag for not updating skip hints
Pageblock skip hints were added as a heuristic for compaction, which
shares core code with CMA. Since CMA reliability would suffer from the
heuristics, compact_control flag ignore_skip_hint was added for the CMA
use case. Since
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Oscar Salvador | 0cd842f970 |
mm: make alloc_node_mem_map a void call if we don't have CONFIG_FLAT_NODE_MEM_MAP
free_area_init_node() calls alloc_node_mem_map(), but this function does nothing unless we have CONFIG_FLAT_NODE_MEM_MAP. As a cleanup, we can move the "#ifdef CONFIG_FLAT_NODE_MEM_MAP" within alloc_node_mem_map() out of the function, and define a alloc_node_mem_map() { } when CONFIG_FLAT_NODE_MEM_MAP is not present. This also moves the printk that lays within the "#ifdef CONFIG_FLAT_NODE_MEM_MAP" block from free_area_init_node() to alloc_node_mem_map(), getting rid of the "#ifdef CONFIG_FLAT_NODE_MEM_MAP" in free_area_init_node(). [akpm@linux-foundation.org: clean up the printk while we're there] Link: http://lkml.kernel.org/r/20171114111935.GA11758@techadventures.net Signed-off-by: Oscar Salvador <osalvador@techadventures.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 0205f75571 |
mm: simplify nodemask printing
alloc_warn() and dump_header() have to explicitly handle NULL nodemask which forces both paths to use pr_cont. We can do better. printk already handles NULL pointers properly so all we need is to teach nodemask_pr_args to handle NULL nodemask carefully. This allows simplification of both alloc_warn() and dump_header() and gets rid of pr_cont altogether. This patch has been motivated by patch from Joe Perches http://lkml.kernel.org/r/b31236dfe3fc924054fd7842bde678e71d193638.1509991345.git.joe@perches.com [akpm@linux-foundation.org: fix tile warning, per Arnd] Link: http://lkml.kernel.org/r/20171109100531.3cn2hcqnuj7mjaju@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Joe Perches <joe@perches.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | d135e57502 |
mm/page_alloc.c: broken deferred calculation
In reset_deferred_meminit() we determine number of pages that must not
be deferred. We initialize pages for at least 2G of memory, but also
pages for reserved memory in this node.
The reserved memory is determined in this function:
memblock_reserved_memory_within(), which operates over physical
addresses, and returns size in bytes. However, reset_deferred_meminit()
assumes that that this function operates with pfns, and returns page
count.
The result is that in the best case machine boots slower than expected
due to initializing more pages than needed in single thread, and in the
worst case panics because fewer than needed pages are initialized early.
Link: http://lkml.kernel.org/r/20171021011707.15191-1-pasha.tatashin@oracle.com
Fixes:
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Tetsuo Handa | 400e22499d |
mm: don't warn about allocations which stall for too long
Commit |
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Vlastimil Babka | b050e3769c |
mm, page_alloc: fix potential false positive in __zone_watermark_ok
Since commit |
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Kemi Wang | 4518085e12 |
mm, sysctl: make NUMA stats configurable
This is the second step which introduces a tunable interface that allow numa stats configurable for optimizing zone_statistics(), as suggested by Dave Hansen and Ying Huang. ========================================================================= When page allocation performance becomes a bottleneck and you can tolerate some possible tool breakage and decreased numa counter precision, you can do: echo 0 > /proc/sys/vm/numa_stat In this case, numa counter update is ignored. We can see about *4.8%*(185->176) drop of cpu cycles per single page allocation and reclaim on Jesper's page_bench01 (single thread) and *8.1%*(343->315) drop of cpu cycles per single page allocation and reclaim on Jesper's page_bench03 (88 threads) running on a 2-Socket Broadwell-based server (88 threads, 126G memory). Benchmark link provided by Jesper D Brouer (increase loop times to 10000000): https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench ========================================================================= When page allocation performance is not a bottleneck and you want all tooling to work, you can do: echo 1 > /proc/sys/vm/numa_stat This is system default setting. Many thanks to Michal Hocko, Dave Hansen, Ying Huang and Vlastimil Babka for comments to help improve the original patch. [keescook@chromium.org: make sure mutex is a global static] Link: http://lkml.kernel.org/r/20171107213809.GA4314@beast Link: http://lkml.kernel.org/r/1508290927-8518-1-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang <kemi.wang@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Suggested-by: Dave Hansen <dave.hansen@intel.com> Suggested-by: Ying Huang <ying.huang@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christopher Lameter <cl@linux.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 0fac3ba527 |
mm, page_alloc: simplify list handling in rmqueue_bulk()
rmqueue_bulk() fills an empty pcplist with pages from the free list. It
tries to preserve increasing order by pfn to the caller, because it
leads to better performance with some I/O controllers, as explained in
commit
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Mel Gorman | 453f85d43f |
mm: remove __GFP_COLD
As the page free path makes no distinction between cache hot and cold pages, there is no real useful ordering of pages in the free list that allocation requests can take advantage of. Juding from the users of __GFP_COLD, it is likely that a number of them are the result of copying other sites instead of actually measuring the impact. Remove the __GFP_COLD parameter which simplifies a number of paths in the page allocator. This is potentially controversial but bear in mind that the size of the per-cpu pagelists versus modern cache sizes means that the whole per-cpu list can often fit in the L3 cache. Hence, there is only a potential benefit for microbenchmarks that alloc/free pages in a tight loop. It's even worse when THP is taken into account which has little or no chance of getting a cache-hot page as the per-cpu list is bypassed and the zeroing of multiple pages will thrash the cache anyway. The truncate microbenchmarks are not shown as this patch affects the allocation path and not the free path. A page fault microbenchmark was tested but it showed no sigificant difference which is not surprising given that the __GFP_COLD branches are a miniscule percentage of the fault path. Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman | 2d4894b5d2 |
mm: remove cold parameter from free_hot_cold_page*
Most callers users of free_hot_cold_page claim the pages being released are cache hot. The exception is the page reclaim paths where it is likely that enough pages will be freed in the near future that the per-cpu lists are going to be recycled and the cache hotness information is lost. As no one really cares about the hotness of pages being released to the allocator, just ditch the parameter. The APIs are renamed to indicate that it's no longer about hot/cold pages. It should also be less confusing as there are subtle differences between them. __free_pages drops a reference and frees a page when the refcount reaches zero. free_hot_cold_page handled pages whose refcount was already zero which is non-obvious from the name. free_unref_page should be more obvious. No performance impact is expected as the overhead is marginal. The parameter is removed simply because it is a bit stupid to have a useless parameter copied everywhere. [mgorman@techsingularity.net: add pages to head, not tail] Link: http://lkml.kernel.org/r/20171019154321.qtpzaeftoyyw4iey@techsingularity.net Link: http://lkml.kernel.org/r/20171018075952.10627-8-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman | 9cca35d42e |
mm, page_alloc: enable/disable IRQs once when freeing a list of pages
Patch series "Follow-up for speed up page cache truncation", v2. This series is a follow-on for Jan Kara's series "Speed up page cache truncation" series. We both ended up looking at the same problem but saw different problems based on the same data. This series builds upon his work. A variety of workloads were compared on four separate machines but each machine showed gains albeit at different levels. Minimally, some of the differences are due to NUMA where truncating data from a remote node is slower than a local node. The workloads checked were o sparse truncate microbenchmark, tiny o sparse truncate microbenchmark, large o reaim-io disk workfile o dbench4 (modified by mmtests to produce more stable results) o filebench varmail configuration for small memory size o bonnie, directory operations, working set size 2*RAM reaim-io, dbench and filebench all showed minor gains. Truncation does not dominate those workloads but were tested to ensure no other regressions. They will not be reported further. The sparse truncate microbench was written by Jan. It creates a number of files and then times how long it takes to truncate each one. The "tiny" configuraiton creates a number of files that easily fits in memory and times how long it takes to truncate files with page cache. The large configuration uses enough files to have data that is twice the size of memory and so timings there include truncating page cache and working set shadow entries in the radix tree. Patches 1-4 are the most relevant parts of this series. Patches 5-8 are optional as they are deleting code that is essentially useless but has a negligible performance impact. The changelogs have more information on performance but just for bonnie delete options, the main comparison is bonnie 4.14.0-rc5 4.14.0-rc5 4.14.0-rc5 jan-v2 vanilla mel-v2 Hmean SeqCreate ops 76.20 ( 0.00%) 75.80 ( -0.53%) 76.80 ( 0.79%) Hmean SeqCreate read 85.00 ( 0.00%) 85.00 ( 0.00%) 85.00 ( 0.00%) Hmean SeqCreate del 13752.31 ( 0.00%) 12090.23 ( -12.09%) 15304.84 ( 11.29%) Hmean RandCreate ops 76.00 ( 0.00%) 75.60 ( -0.53%) 77.00 ( 1.32%) Hmean RandCreate read 96.80 ( 0.00%) 96.80 ( 0.00%) 97.00 ( 0.21%) Hmean RandCreate del 13233.75 ( 0.00%) 11525.35 ( -12.91%) 14446.61 ( 9.16%) Jan's series is the baseline and the vanilla kernel is 12% slower where as this series on top gains another 11%. This is from a different machine than the data in the changelogs but the detailed data was not collected as there was no substantial change in v2. This patch (of 8): Freeing a list of pages current enables/disables IRQs for each page freed. This patch splits freeing a list of pages into two operations -- preparing the pages for freeing and the actual freeing. This is a tradeoff - we're taking two passes of the list to free in exchange for avoiding multiple enable/disable of IRQs. sparsetruncate (tiny) 4.14.0-rc4 4.14.0-rc4 janbatch-v1r1 oneirq-v1r1 Min Time 149.00 ( 0.00%) 141.00 ( 5.37%) 1st-qrtle Time 150.00 ( 0.00%) 142.00 ( 5.33%) 2nd-qrtle Time 151.00 ( 0.00%) 142.00 ( 5.96%) 3rd-qrtle Time 151.00 ( 0.00%) 143.00 ( 5.30%) Max-90% Time 153.00 ( 0.00%) 144.00 ( 5.88%) Max-95% Time 155.00 ( 0.00%) 147.00 ( 5.16%) Max-99% Time 201.00 ( 0.00%) 195.00 ( 2.99%) Max Time 236.00 ( 0.00%) 230.00 ( 2.54%) Amean Time 152.65 ( 0.00%) 144.37 ( 5.43%) Stddev Time 9.78 ( 0.00%) 10.44 ( -6.72%) Coeff Time 6.41 ( 0.00%) 7.23 ( -12.84%) Best99%Amean Time 152.07 ( 0.00%) 143.72 ( 5.50%) Best95%Amean Time 150.75 ( 0.00%) 142.37 ( 5.56%) Best90%Amean Time 150.59 ( 0.00%) 142.19 ( 5.58%) Best75%Amean Time 150.36 ( 0.00%) 141.92 ( 5.61%) Best50%Amean Time 150.04 ( 0.00%) 141.69 ( 5.56%) Best25%Amean Time 149.85 ( 0.00%) 141.38 ( 5.65%) With a tiny number of files, each file truncated has resident page cache and it shows that time to truncate is roughtly 5-6% with some minor jitter. 4.14.0-rc4 4.14.0-rc4 janbatch-v1r1 oneirq-v1r1 Hmean SeqCreate ops 65.27 ( 0.00%) 81.86 ( 25.43%) Hmean SeqCreate read 39.48 ( 0.00%) 47.44 ( 20.16%) Hmean SeqCreate del 24963.95 ( 0.00%) 26319.99 ( 5.43%) Hmean RandCreate ops 65.47 ( 0.00%) 82.01 ( 25.26%) Hmean RandCreate read 42.04 ( 0.00%) 51.75 ( 23.09%) Hmean RandCreate del 23377.66 ( 0.00%) 23764.79 ( 1.66%) As expected, there is a small gain for the delete operation. [mgorman@techsingularity.net: use page_private and set_page_private helpers] Link: http://lkml.kernel.org/r/20171018101547.mjycw7zreb66jzpa@techsingularity.net Link: http://lkml.kernel.org/r/20171018075952.10627-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Kara <jack@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aaron Lu | 85ccc8fa81 |
mm/page_alloc: make sure __rmqueue() etc are always inline
__rmqueue(), __rmqueue_fallback(), __rmqueue_smallest() and __rmqueue_cma_fallback() are all in page allocator's hot path and better be finished as soon as possible. One way to make them faster is by making them inline. But as Andrew Morton and Andi Kleen pointed out: https://lkml.org/lkml/2017/10/10/1252 https://lkml.org/lkml/2017/10/10/1279 To make sure they are inlined, we should use __always_inline for them. With the will-it-scale/page_fault1/process benchmark, when using nr_cpu processes to stress buddy, the results for will-it-scale.processes with and without the patch are: On a 2-sockets Intel-Skylake machine: compiler base head gcc-4.4.7 6496131 6911823 +6.4% gcc-4.9.4 7225110 7731072 +7.0% gcc-5.4.1 7054224 7688146 +9.0% gcc-6.2.0 7059794 7651675 +8.4% On a 4-sockets Intel-Skylake machine: compiler base head gcc-4.4.7 13162890 13508193 +2.6% gcc-4.9.4 14997463 15484353 +3.2% gcc-5.4.1 14708711 15449805 +5.0% gcc-6.2.0 14574099 15349204 +5.3% The above 4 compilers are used because I've done the tests through Intel's Linux Kernel Performance(LKP) infrastructure and they are the available compilers there. The benefit being less on 4 sockets machine is due to the lock contention there(perf-profile/native_queued_spin_lock_slowpath=81%) is less severe than on the 2 sockets machine(85%). What the benchmark does is: it forks nr_cpu processes and then each process does the following: 1 mmap() 128M anonymous space; 2 writes to each page there to trigger actual page allocation; 3 munmap() it. in a loop. https://github.com/antonblanchard/will-it-scale/blob/master/tests/page_fault1.c Binary size wise, I have locally built them with different compilers: [aaron@aaronlu obj]$ size */*/mm/page_alloc.o text data bss dec hex filename 37409 9904 8524 55837 da1d gcc-4.9.4/base/mm/page_alloc.o 38273 9904 8524 56701 dd7d gcc-4.9.4/head/mm/page_alloc.o 37465 9840 8428 55733 d9b5 gcc-5.5.0/base/mm/page_alloc.o 38169 9840 8428 56437 dc75 gcc-5.5.0/head/mm/page_alloc.o 37573 9840 8428 55841 da21 gcc-6.4.0/base/mm/page_alloc.o 38261 9840 8428 56529 dcd1 gcc-6.4.0/head/mm/page_alloc.o 36863 9840 8428 55131 d75b gcc-7.2.0/base/mm/page_alloc.o 37711 9840 8428 55979 daab gcc-7.2.0/head/mm/page_alloc.o Text size increased about 800 bytes for mm/page_alloc.o. [aaron@aaronlu obj]$ size */*/vmlinux text data bss dec hex filename 10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/base/vmlinux 10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/head/vmlinux 10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/base/vmlinux 10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/head/vmlinux 10094546 5836696 17715200 33646442 201676a gcc-6.4.0/base/vmlinux 10094546 5836696 17715200 33646442 201676a gcc-6.4.0/head/vmlinux 10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/base/vmlinux 10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/head/vmlinux Text size for vmlinux has no change though, probably due to function alignment. Link: http://lkml.kernel.org/r/20171013063111.GA26032@intel.com Signed-off-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Kemi Wang <kemi.wang@intel.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | f7f99100d8 |
mm: stop zeroing memory during allocation in vmemmap
vmemmap_alloc_block() will no longer zero the block, so zero memory at its call sites for everything except struct pages. Struct page memory is zero'd by struct page initialization. Replace allocators in sparse-vmemmap to use the non-zeroing version. So, we will get the performance improvement by zeroing the memory in parallel when struct pages are zeroed. Add struct page zeroing as a part of initialization of other fields in __init_single_page(). This single thread performance collected on: Intel(R) Xeon(R) CPU E7-8895 v3 @ 2.60GHz with 1T of memory (268400646 pages in 8 nodes): BASE FIX sparse_init 11.244671836s 0.007199623s zone_sizes_init 4.879775891s 8.355182299s -------------------------- Total 16.124447727s 8.362381922s sparse_init is where memory for struct pages is zeroed, and the zeroing part is moved later in this patch into __init_single_page(), which is called from zone_sizes_init(). [akpm@linux-foundation.org: make vmemmap_alloc_block_zero() private to sparse-vmemmap.c] Link: http://lkml.kernel.org/r/20171013173214.27300-10-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Tested-by: Bob Picco <bob.picco@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | a4a3ede213 |
mm: zero reserved and unavailable struct pages
Some memory is reserved but unavailable: not present in memblock.memory (because not backed by physical pages), but present in memblock.reserved. Such memory has backing struct pages, but they are not initialized by going through __init_single_page(). In some cases these struct pages are accessed even if they do not contain any data. One example is page_to_pfn() might access page->flags if this is where section information is stored (CONFIG_SPARSEMEM, SECTION_IN_PAGE_FLAGS). One example of such memory: trim_low_memory_range() unconditionally reserves from pfn 0, but e820__memblock_setup() might provide the exiting memory from pfn 1 (i.e. KVM). Since struct pages are zeroed in __init_single_page(), and not during allocation time, we must zero such struct pages explicitly. The patch involves adding a new memblock iterator: for_each_resv_unavail_range(i, p_start, p_end) Which iterates through reserved && !memory lists, and we zero struct pages explicitly by calling mm_zero_struct_page(). === Here is more detailed example of problem that this patch is addressing: Run tested on qemu with the following arguments: -enable-kvm -cpu kvm64 -m 512 -smp 2 This patch reports that there are 98 unavailable pages. They are: pfn 0 and pfns in range [159, 255]. Note, trim_low_memory_range() reserves only pfns in range [0, 15], it does not reserve [159, 255] ones. e820__memblock_setup() reports linux that the following physical ranges are available: [1 , 158] [256, 130783] Notice, that exactly unavailable pfns are missing! Now, lets check what we have in zone 0: [1, 131039] pfn 0, is not part of the zone, but pfns [1, 158], are. However, the bigger problem we have if we do not initialize these struct pages is with memory hotplug. Because, that path operates at 2M boundaries (section_nr). And checks if 2M range of pages is hot removable. It starts with first pfn from zone, rounds it down to 2M boundary (sturct pages are allocated at 2M boundaries when vmemmap is created), and checks if that section is hot removable. In this case start with pfn 1 and convert it down to pfn 0. Later pfn is converted to struct page, and some fields are checked. Now, if we do not zero struct pages, we get unpredictable results. In fact when CONFIG_VM_DEBUG is enabled, and we explicitly set all vmemmap memory to ones, the following panic is observed with kernel test without this patch applied: BUG: unable to handle kernel NULL pointer dereference at (null) IP: is_pageblock_removable_nolock+0x35/0x90 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT ... task: ffff88001f4e2900 task.stack: ffffc90000314000 RIP: 0010:is_pageblock_removable_nolock+0x35/0x90 Call Trace: ? is_mem_section_removable+0x5a/0xd0 show_mem_removable+0x6b/0xa0 dev_attr_show+0x1b/0x50 sysfs_kf_seq_show+0xa1/0x100 kernfs_seq_show+0x22/0x30 seq_read+0x1ac/0x3a0 kernfs_fop_read+0x36/0x190 ? security_file_permission+0x90/0xb0 __vfs_read+0x16/0x30 vfs_read+0x81/0x130 SyS_read+0x44/0xa0 entry_SYSCALL_64_fastpath+0x1f/0xbd Link: http://lkml.kernel.org/r/20171013173214.27300-7-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Tested-by: Bob Picco <bob.picco@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | ea1f5f3712 |
mm: define memblock_virt_alloc_try_nid_raw
* A new variant of memblock_virt_alloc_* allocations: memblock_virt_alloc_try_nid_raw() - Does not zero the allocated memory - Does not panic if request cannot be satisfied * optimize early system hash allocations Clients can call alloc_large_system_hash() with flag: HASH_ZERO to specify that memory that was allocated for system hash needs to be zeroed, otherwise the memory does not need to be zeroed, and client will initialize it. If memory does not need to be zero'd, call the new memblock_virt_alloc_raw() interface, and thus improve the boot performance. * debug for raw alloctor When CONFIG_DEBUG_VM is enabled, this patch sets all the memory that is returned by memblock_virt_alloc_try_nid_raw() to ones to ensure that no places excpect zeroed memory. Link: http://lkml.kernel.org/r/20171013173214.27300-6-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Tested-by: Bob Picco <bob.picco@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | 2f47a91f4d |
mm: deferred_init_memmap improvements
Patch series "complete deferred page initialization", v12. SMP machines can benefit from the DEFERRED_STRUCT_PAGE_INIT config option, which defers initializing struct pages until all cpus have been started so it can be done in parallel. However, this feature is sub-optimal, because the deferred page initialization code expects that the struct pages have already been zeroed, and the zeroing is done early in boot with a single thread only. Also, we access that memory and set flags before struct pages are initialized. All of this is fixed in this patchset. In this work we do the following: - Never read access struct page until it was initialized - Never set any fields in struct pages before they are initialized - Zero struct page at the beginning of struct page initialization ========================================================================== Performance improvements on x86 machine with 8 nodes: Intel(R) Xeon(R) CPU E7-8895 v3 @ 2.60GHz and 1T of memory: TIME SPEED UP base no deferred: 95.796233s fix no deferred: 79.978956s 19.77% base deferred: 77.254713s fix deferred: 55.050509s 40.34% ========================================================================== SPARC M6 3600 MHz with 15T of memory TIME SPEED UP base no deferred: 358.335727s fix no deferred: 302.320936s 18.52% base deferred: 237.534603s fix deferred: 182.103003s 30.44% ========================================================================== Raw dmesg output with timestamps: x86 base no deferred: https://hastebin.com/ofunepurit.scala x86 base deferred: https://hastebin.com/ifazegeyas.scala x86 fix no deferred: https://hastebin.com/pegocohevo.scala x86 fix deferred: https://hastebin.com/ofupevikuk.scala sparc base no deferred: https://hastebin.com/ibobeteken.go sparc base deferred: https://hastebin.com/fariqimiyu.go sparc fix no deferred: https://hastebin.com/muhegoheyi.go sparc fix deferred: https://hastebin.com/xadinobutu.go This patch (of 11): deferred_init_memmap() is called when struct pages are initialized later in boot by slave CPUs. This patch simplifies and optimizes this function, and also fixes a couple issues (described below). The main change is that now we are iterating through free memblock areas instead of all configured memory. Thus, we do not have to check if the struct page has already been initialized. ===== In deferred_init_memmap() where all deferred struct pages are initialized we have a check like this: if (page->flags) { VM_BUG_ON(page_zone(page) != zone); goto free_range; } This way we are checking if the current deferred page has already been initialized. It works, because memory for struct pages has been zeroed, and the only way flags are not zero if it went through __init_single_page() before. But, once we change the current behavior and won't zero the memory in memblock allocator, we cannot trust anything inside "struct page"es until they are initialized. This patch fixes this. The deferred_init_memmap() is re-written to loop through only free memory ranges provided by memblock. Note, this first issue is relevant only when the following change is merged: ===== This patch fixes another existing issue on systems that have holes in zones i.e CONFIG_HOLES_IN_ZONE is defined. In for_each_mem_pfn_range() we have code like this: if (!pfn_valid_within(pfn) goto free_range; Note: 'page' is not set to NULL and is not incremented but 'pfn' advances. Thus means if deferred struct pages are enabled on systems with these kind of holes, linux would get memory corruptions. I have fixed this issue by defining a new macro that performs all the necessary operations when we free the current set of pages. [pasha.tatashin@oracle.com: buddy page accessed before initialized] Link: http://lkml.kernel.org/r/20171102170221.7401-2-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20171013173214.27300-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Tested-by: Bob Picco <bob.picco@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Levin, Alexander (Sasha Levin) | 4950276672 |
kmemcheck: remove annotations
Patch series "kmemcheck: kill kmemcheck", v2. As discussed at LSF/MM, kill kmemcheck. KASan is a replacement that is able to work without the limitation of kmemcheck (single CPU, slow). KASan is already upstream. We are also not aware of any users of kmemcheck (or users who don't consider KASan as a suitable replacement). The only objection was that since KASAN wasn't supported by all GCC versions provided by distros at that time we should hold off for 2 years, and try again. Now that 2 years have passed, and all distros provide gcc that supports KASAN, kill kmemcheck again for the very same reasons. This patch (of 4): Remove kmemcheck annotations, and calls to kmemcheck from the kernel. [alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs] Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Cc: Alexander Potapenko <glider@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Hansen <devtimhansen@gmail.com> Cc: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | d7ab3672c3 |
mm, page_alloc: fail has_unmovable_pages when seeing reserved pages
Reserved pages should be completely ignored by the core mm because they have a special meaning for their owners. has_unmovable_pages doesn't check those so we rely on other tests (reference count, or PageLRU) to fail on such pages. Althought this happens to work it is safer to simply check for those explicitly and do not rely on the owner of the page to abuse those fields for special purposes. Please note that this is more of a further fortification of the code rahter than a fix of an existing issue. Link: http://lkml.kernel.org/r/20171013120756.jeopthigbmm3c7bl@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Igor Mammedov <imammedo@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 4da2ce250f |
mm: distinguish CMA and MOVABLE isolation in has_unmovable_pages()
Joonsoo has noticed that "mm: drop migrate type checks from has_unmovable_pages" would break CMA allocator because it relies on has_unmovable_pages returning false even for CMA pageblocks which in fact don't have to be movable: alloc_contig_range start_isolate_page_range set_migratetype_isolate has_unmovable_pages This is a result of the code sharing between CMA and memory hotplug while each one has a different idea of what has_unmovable_pages should return. This is unfortunate but fixing it properly would require a lot of code duplication. Fix the issue by introducing the requested migrate type argument and special case MIGRATE_CMA case where CMA page blocks are handled properly. This will work for memory hotplug because it requires MIGRATE_MOVABLE. Link: http://lkml.kernel.org/r/20171019122118.y6cndierwl2vnguj@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Ran Wang <ran.wang_1@nxp.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Igor Mammedov <imammedo@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | d7b236e10c |
mm: drop migrate type checks from has_unmovable_pages
Michael has noticed that the memory offline tries to migrate kernel code pages when doing echo 0 > /sys/devices/system/memory/memory0/online The current implementation will fail the operation after several failed page migration attempts but we shouldn't even attempt to migrate that memory and fail right away because this memory is clearly not migrateable. This will become a real problem when we drop the retry loop counter resp. timeout. The real problem is in has_unmovable_pages in fact. We should fail if there are any non migrateable pages in the area. In orther to guarantee that remove the migrate type checks because MIGRATE_MOVABLE is not guaranteed to contain only migrateable pages. It is merely a heuristic. Similarly MIGRATE_CMA does guarantee that the page allocator doesn't allocate any non-migrateable pages from the block but CMA allocations themselves are unlikely to migrateable. Therefore remove both checks. [akpm@linux-foundation.org: remove unused local `mt'] Link: http://lkml.kernel.org/r/20171013120013.698-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ran Wang <ran.wang_1@nxp.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 9b6e63cbf8 |
mm, page_alloc: add scheduling point to memmap_init_zone
memmap_init_zone gets a pfn range to initialize and it can be really large resulting in a soft lockup on non-preemptible kernels NMI watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [kworker/u642:5:1720] [...] task: ffff88ecd7e902c0 ti: ffff88eca4e50000 task.ti: ffff88eca4e50000 RIP: move_pfn_range_to_zone+0x185/0x1d0 [...] Call Trace: devm_memremap_pages+0x2c7/0x430 pmem_attach_disk+0x2fd/0x3f0 [nd_pmem] nvdimm_bus_probe+0x64/0x110 [libnvdimm] driver_probe_device+0x1f7/0x420 bus_for_each_drv+0x52/0x80 __device_attach+0xb0/0x130 bus_probe_device+0x87/0xa0 device_add+0x3fc/0x5f0 nd_async_device_register+0xe/0x40 [libnvdimm] async_run_entry_fn+0x43/0x150 process_one_work+0x14e/0x410 worker_thread+0x116/0x490 kthread+0xc7/0xe0 ret_from_fork+0x3f/0x70 Fix this by adding a scheduling point once per page block. Link: http://lkml.kernel.org/r/20170918121410.24466-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Johannes Thumshirn <jthumshirn@suse.de> Tested-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Dan Williams <dan.j.williams@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Arnd Bergmann | 57148a64e8 |
mm: meminit: mark init_reserved_page as __meminit
The function is called from __meminit context and calls other __meminit
functions but isn't it self mark as such today:
WARNING: vmlinux.o(.text.unlikely+0x4516): Section mismatch in reference from the function init_reserved_page() to the function .meminit.text:early_pfn_to_nid()
The function init_reserved_page() references the function __meminit early_pfn_to_nid().
This is often because init_reserved_page lacks a __meminit annotation or the annotation of early_pfn_to_nid is wrong.
On most compilers, we don't notice this because the function gets
inlined all the time. Adding __meminit here fixes the harmless warning
for the old versions and is generally the correct annotation.
Link: http://lkml.kernel.org/r/20170915193149.901180-1-arnd@arndb.de
Fixes:
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Tetsuo Handa | f19360f015 |
mm/page_alloc.c: apply gfp_allowed_mask before the first allocation attempt
We are by error initializing alloc_flags before gfp_allowed_mask is
applied. This could cause problems after pm_restrict_gfp_mask() is called
during suspend operation. Apply gfp_allowed_mask before initializing
alloc_flags so that the first allocation attempt uses correct flags.
Link: http://lkml.kernel.org/r/201709020016.ADJ21342.OFLJHOOSMFVtFQ@I-love.SAKURA.ne.jp
Fixes:
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Kemi Wang | 3a321d2a3d |
mm: change the call sites of numa statistics items
Patch series "Separate NUMA statistics from zone statistics", v2. Each page allocation updates a set of per-zone statistics with a call to zone_statistics(). As discussed in 2017 MM summit, these are a substantial source of overhead in the page allocator and are very rarely consumed. This significant overhead in cache bouncing caused by zone counters (NUMA associated counters) update in parallel in multi-threaded page allocation (pointed out by Dave Hansen). A link to the MM summit slides: http://people.netfilter.org/hawk/presentations/MM-summit2017/MM-summit2017-JesperBrouer.pdf To mitigate this overhead, this patchset separates NUMA statistics from zone statistics framework, and update NUMA counter threshold to a fixed size of MAX_U16 - 2, as a small threshold greatly increases the update frequency of the global counter from local per cpu counter (suggested by Ying Huang). The rationality is that these statistics counters don't need to be read often, unlike other VM counters, so it's not a problem to use a large threshold and make readers more expensive. With this patchset, we see 31.3% drop of CPU cycles(537-->369, see below) for per single page allocation and reclaim on Jesper's page_bench03 benchmark. Meanwhile, this patchset keeps the same style of virtual memory statistics with little end-user-visible effects (only move the numa stats to show behind zone page stats, see the first patch for details). I did an experiment of single page allocation and reclaim concurrently using Jesper's page_bench03 benchmark on a 2-Socket Broadwell-based server (88 processors with 126G memory) with different size of threshold of pcp counter. Benchmark provided by Jesper D Brouer(increase loop times to 10000000): https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench Threshold CPU cycles Throughput(88 threads) 32 799 241760478 64 640 301628829 125 537 358906028 <==> system by default 256 468 412397590 512 428 450550704 4096 399 482520943 20000 394 489009617 30000 395 488017817 65533 369(-31.3%) 521661345(+45.3%) <==> with this patchset N/A 342(-36.3%) 562900157(+56.8%) <==> disable zone_statistics This patch (of 3): In this patch, NUMA statistics is separated from zone statistics framework, all the call sites of NUMA stats are changed to use numa-stats-specific functions, it does not have any functionality change except that the number of NUMA stats is shown behind zone page stats when users *read* the zone info. E.g. cat /proc/zoneinfo ***Base*** ***With this patch*** nr_free_pages 3976 nr_free_pages 3976 nr_zone_inactive_anon 0 nr_zone_inactive_anon 0 nr_zone_active_anon 0 nr_zone_active_anon 0 nr_zone_inactive_file 0 nr_zone_inactive_file 0 nr_zone_active_file 0 nr_zone_active_file 0 nr_zone_unevictable 0 nr_zone_unevictable 0 nr_zone_write_pending 0 nr_zone_write_pending 0 nr_mlock 0 nr_mlock 0 nr_page_table_pages 0 nr_page_table_pages 0 nr_kernel_stack 0 nr_kernel_stack 0 nr_bounce 0 nr_bounce 0 nr_zspages 0 nr_zspages 0 numa_hit 0 *nr_free_cma 0* numa_miss 0 numa_hit 0 numa_foreign 0 numa_miss 0 numa_interleave 0 numa_foreign 0 numa_local 0 numa_interleave 0 numa_other 0 numa_local 0 *nr_free_cma 0* numa_other 0 ... ... vm stats threshold: 10 vm stats threshold: 10 ... ... The next patch updates the numa stats counter size and threshold. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1503568801-21305-2-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang <kemi.wang@intel.com> Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Ying Huang <ying.huang@intel.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | cd04ae1e2d |
mm, oom: do not rely on TIF_MEMDIE for memory reserves access
For ages we have been relying on TIF_MEMDIE thread flag to mark OOM
victims and then, among other things, to give these threads full access
to memory reserves. There are few shortcomings of this implementation,
though.
First of all and the most serious one is that the full access to memory
reserves is quite dangerous because we leave no safety room for the
system to operate and potentially do last emergency steps to move on.
Secondly this flag is per task_struct while the OOM killer operates on
mm_struct granularity so all processes sharing the given mm are killed.
Giving the full access to all these task_structs could lead to a quick
memory reserves depletion. We have tried to reduce this risk by giving
TIF_MEMDIE only to the main thread and the currently allocating task but
that doesn't really solve this problem while it surely opens up a room
for corner cases - e.g. GFP_NO{FS,IO} requests might loop inside the
allocator without access to memory reserves because a particular thread
was not the group leader.
Now that we have the oom reaper and that all oom victims are reapable
after
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Michal Hocko | c41f012ade |
mm: rename global_page_state to global_zone_page_state
global_page_state is error prone as a recent bug report pointed out [1]. It only returns proper values for zone based counters as the enum it gets suggests. We already have global_node_page_state so let's rename global_page_state to global_zone_page_state to be more explicit here. All existing users seems to be correct: $ git grep "global_page_state(NR_" | sed 's@.*(\(NR_[A-Z_]*\)).*@\1@' | sort | uniq -c 2 NR_BOUNCE 2 NR_FREE_CMA_PAGES 11 NR_FREE_PAGES 1 NR_KERNEL_STACK_KB 1 NR_MLOCK 2 NR_PAGETABLE This patch shouldn't introduce any functional change. [1] http://lkml.kernel.org/r/201707260628.v6Q6SmaS030814@www262.sakura.ne.jp Link: http://lkml.kernel.org/r/20170801134256.5400-2-hannes@cmpxchg.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | b93e0f329e |
mm, memory_hotplug: get rid of zonelists_mutex
zonelists_mutex was introduced by commit |
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Michal Hocko | 11cd8638c3 |
mm, page_alloc: remove stop_machine from build_all_zonelists
build_all_zonelists has been (ab)using stop_machine to make sure that
zonelists do not change while somebody is looking at them. This is is
just a gross hack because a) it complicates the context from which we
can call build_all_zonelists (see
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Michal Hocko | 9d3be21bf9 |
mm, page_alloc: simplify zonelist initialization
build_zonelists gradually builds zonelists from the nearest to the most distant node. As we do not know how many populated zones we will have in each node we rely on the _zoneref to terminate initialized part of the zonelist by a NULL zone. While this is functionally correct it is quite suboptimal because we cannot allow updaters to race with zonelists users because they could see an empty zonelist and fail the allocation or hit the OOM killer in the worst case. We can do much better, though. We can store the node ordering into an already existing node_order array and then give this array to build_zonelists_in_node_order and do the whole initialization at once. zonelists consumers still might see halfway initialized state but that should be much more tolerateable because the list will not be empty and they would either see some zone twice or skip over some zone(s) in the worst case which shouldn't lead to immediate failures. While at it let's simplify build_zonelists_node which is rather confusing now. It gets an index into the zoneref array and returns the updated index for the next iteration. Let's rename the function to build_zonerefs_node to better reflect its purpose and give it zoneref array to update. The function doesn't the index anymore. It just returns the number of added zones so that the caller can advance the zonered array start for the next update. This patch alone doesn't introduce any functional change yet, though, it is merely a preparatory work for later changes. Link: http://lkml.kernel.org/r/20170721143915.14161-7-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 72675e131e |
mm, memory_hotplug: drop zone from build_all_zonelists
build_all_zonelists gets a zone parameter to initialize zone's pagesets.
There is only a single user which gives a non-NULL zone parameter and
that one doesn't really need the rest of the build_all_zonelists (see
commit
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Michal Hocko | d9c9a0b972 |
mm, page_alloc: do not set_cpu_numa_mem on empty nodes initialization
__build_all_zonelists reinitializes each online cpu local node for CONFIG_HAVE_MEMORYLESS_NODES. This makes sense because previously memory less nodes could gain some memory during memory hotplug and so the local node should be changed for CPUs close to such a node. It makes less sense to do that unconditionally for a newly creaded NUMA node which is still offline and without any memory. Let's also simplify the cpu loop and use for_each_online_cpu instead of an explicit cpu_online check for all possible cpus. Link: http://lkml.kernel.org/r/20170721143915.14161-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | afb6ebb3fa |
mm, page_alloc: remove boot pageset initialization from memory hotplug
boot_pageset is a boot time hack which gets superseded by normal pagesets later in the boot process. It makes zero sense to reinitialize it again and again during memory hotplug. Link: http://lkml.kernel.org/r/20170721143915.14161-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | c9bff3eebc |
mm, page_alloc: rip out ZONELIST_ORDER_ZONE
Patch series "cleanup zonelists initialization", v1. This is aimed at cleaning up the zonelists initialization code we have but the primary motivation was bug report [2] which got resolved but the usage of stop_machine is just too ugly to live. Most patches are straightforward but 3 of them need a special consideration. Patch 1 removes zone ordered zonelists completely. I am CCing linux-api because this is a user visible change. As I argue in the patch description I do not think we have a strong usecase for it these days. I have kept sysctl in place and warn into the log if somebody tries to configure zone lists ordering. If somebody has a real usecase for it we can revert this patch but I do not expect anybody will actually notice runtime differences. This patch is not strictly needed for the rest but it made patch 6 easier to implement. Patch 7 removes stop_machine from build_all_zonelists without adding any special synchronization between iterators and updater which I _believe_ is acceptable as explained in the changelog. I hope I am not missing anything. Patch 8 then removes zonelists_mutex which is kind of ugly as well and not really needed AFAICS but a care should be taken when double checking my thinking. This patch (of 9): Supporting zone ordered zonelists costs us just a lot of code while the usefulness is arguable if existent at all. Mel has already made node ordering default on 64b systems. 32b systems are still using ZONELIST_ORDER_ZONE because it is considered better to fallback to a different NUMA node rather than consume precious lowmem zones. This argument is, however, weaken by the fact that the memory reclaim has been reworked to be node rather than zone oriented. This means that lowmem requests have to skip over all highmem pages on LRUs already and so zone ordering doesn't save the reclaim time much. So the only advantage of the zone ordering is under a light memory pressure when highmem requests do not ever hit into lowmem zones and the lowmem pressure doesn't need to reclaim. Considering that 32b NUMA systems are rather suboptimal already and it is generally advisable to use 64b kernel on such a HW I believe we should rather care about the code maintainability and just get rid of ZONELIST_ORDER_ZONE altogether. Keep systcl in place and warn if somebody tries to set zone ordering either from kernel command line or the sysctl. [mhocko@suse.com: reading vm.numa_zonelist_order will never terminate] Link: http://lkml.kernel.org/r/20170721143915.14161-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Wei Yang | c11525830f |
mm/memory_hotplug: just build zonelist for newly added node
Commit
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Ingo Molnar | edc2988c54 |
Merge branch 'linus' into locking/core, to fix up conflicts
Conflicts: mm/page_alloc.c Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Tetsuo Handa | e746bf730a |
mm,page_alloc: don't call __node_reclaim() with oom_lock held.
We are doing a last second memory allocation attempt before calling out_of_memory(). But since slab shrinker functions might indirectly wait for other thread's __GFP_DIRECT_RECLAIM && !__GFP_NORETRY memory allocations via sleeping locks, calling slab shrinker functions from node_reclaim() from get_page_from_freelist() with oom_lock held has possibility of deadlock. Therefore, make sure that last second memory allocation attempt does not call slab shrinker functions. Link: http://lkml.kernel.org/r/1503577106-9196-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Chen Yu | 556b969a1c |
PM/hibernate: touch NMI watchdog when creating snapshot
There is a problem that when counting the pages for creating the hibernation snapshot will take significant amount of time, especially on system with large memory. Since the counting job is performed with irq disabled, this might lead to NMI lockup. The following warning were found on a system with 1.5TB DRAM: Freezing user space processes ... (elapsed 0.002 seconds) done. OOM killer disabled. PM: Preallocating image memory... NMI watchdog: Watchdog detected hard LOCKUP on cpu 27 CPU: 27 PID: 3128 Comm: systemd-sleep Not tainted 4.13.0-0.rc2.git0.1.fc27.x86_64 #1 task: ffff9f01971ac000 task.stack: ffffb1a3f325c000 RIP: 0010:memory_bm_find_bit+0xf4/0x100 Call Trace: swsusp_set_page_free+0x2b/0x30 mark_free_pages+0x147/0x1c0 count_data_pages+0x41/0xa0 hibernate_preallocate_memory+0x80/0x450 hibernation_snapshot+0x58/0x410 hibernate+0x17c/0x310 state_store+0xdf/0xf0 kobj_attr_store+0xf/0x20 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x11c/0x1a0 __vfs_write+0x37/0x170 vfs_write+0xb1/0x1a0 SyS_write+0x55/0xc0 entry_SYSCALL_64_fastpath+0x1a/0xa5 ... done (allocated 6590003 pages) PM: Allocated 26360012 kbytes in 19.89 seconds (1325.28 MB/s) It has taken nearly 20 seconds(2.10GHz CPU) thus the NMI lockup was triggered. In case the timeout of the NMI watch dog has been set to 1 second, a safe interval should be 6590003/20 = 320k pages in theory. However there might also be some platforms running at a lower frequency, so feed the watchdog every 100k pages. [yu.c.chen@intel.com: simplification] Link: http://lkml.kernel.org/r/1503460079-29721-1-git-send-email-yu.c.chen@intel.com [yu.c.chen@intel.com: use interval of 128k instead of 100k to avoid modulus] Link: http://lkml.kernel.org/r/1503328098-5120-1-git-send-email-yu.c.chen@intel.com Signed-off-by: Chen Yu <yu.c.chen@intel.com> Reported-by: Jan Filipcewicz <jan.filipcewicz@intel.com> Suggested-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Len Brown <lenb@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Ingo Molnar | 10c9850cb2 |
Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Pavel Tatashin | 3010f87650 |
mm: discard memblock data later
There is existing use after free bug when deferred struct pages are
enabled:
The memblock_add() allocates memory for the memory array if more than
128 entries are needed. See comment in e820__memblock_setup():
* The bootstrap memblock region count maximum is 128 entries
* (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
* than that - so allow memblock resizing.
This memblock memory is freed here:
free_low_memory_core_early()
We access the freed memblock.memory later in boot when deferred pages
are initialized in this path:
deferred_init_memmap()
for_each_mem_pfn_range()
__next_mem_pfn_range()
type = &memblock.memory;
One possible explanation for why this use-after-free hasn't been hit
before is that the limit of INIT_MEMBLOCK_REGIONS has never been
exceeded at least on systems where deferred struct pages were enabled.
Tested by reducing INIT_MEMBLOCK_REGIONS down to 4 from the current 128,
and verifying in qemu that this code is getting excuted and that the
freed pages are sane.
Link: http://lkml.kernel.org/r/1502485554-318703-2-git-send-email-pasha.tatashin@oracle.com
Fixes:
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Ingo Molnar | 040cca3ab2 |
Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
include/linux/mm_types.h
mm/huge_memory.c
I removed the smp_mb__before_spinlock() like the following commit does:
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Jonathan Toppins | 75dddef325 |
mm: ratelimit PFNs busy info message
The RDMA subsystem can generate several thousand of these messages per second eventually leading to a kernel crash. Ratelimit these messages to prevent this crash. Doug said: "I've been carrying a version of this for several kernel versions. I don't remember when they started, but we have one (and only one) class of machines: Dell PE R730xd, that generate these errors. When it happens, without a rate limit, we get rcu timeouts and kernel oopses. With the rate limit, we just get a lot of annoying kernel messages but the machine continues on, recovers, and eventually the memory operations all succeed" And: "> Well... why are all these EBUSY's occurring? It sounds inefficient > (at least) but if it is expected, normal and unavoidable then > perhaps we should just remove that message altogether? I don't have an answer to that question. To be honest, I haven't looked real hard. We never had this at all, then it started out of the blue, but only on our Dell 730xd machines (and it hits all of them), but no other classes or brands of machines. And we have our 730xd machines loaded up with different brands and models of cards (for instance one dedicated to mlx4 hardware, one for qib, one for mlx5, an ocrdma/cxgb4 combo, etc), so the fact that it hit all of the machines meant it wasn't tied to any particular brand/model of RDMA hardware. To me, it always smelled of a hardware oddity specific to maybe the CPUs or mainboard chipsets in these machines, so given that I'm not an mm expert anyway, I never chased it down. A few other relevant details: it showed up somewhere around 4.8/4.9 or thereabouts. It never happened before, but the prinkt has been there since the 3.18 days, so possibly the test to trigger this message was changed, or something else in the allocator changed such that the situation started happening on these machines? And, like I said, it is specific to our 730xd machines (but they are all identical, so that could mean it's something like their specific ram configuration is causing the allocator to hit this on these machine but not on other machines in the cluster, I don't want to say it's necessarily the model of chipset or CPU, there are other bits of identicalness between these machines)" Link: http://lkml.kernel.org/r/499c0f6cc10d6eb829a67f2a4d75b4228a9b356e.1501695897.git.jtoppins@redhat.com Signed-off-by: Jonathan Toppins <jtoppins@redhat.com> Reviewed-by: Doug Ledford <dledford@redhat.com> Tested-by: Doug Ledford <dledford@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Johannes Weiner | d507e2ebd2 |
mm: fix global NR_SLAB_.*CLAIMABLE counter reads
As Tetsuo points out: "Commit |
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Peter Zijlstra | d92a8cfcb3 |
locking/lockdep: Rework FS_RECLAIM annotation
A while ago someone, and I cannot find the email just now, asked if we could not implement the RECLAIM_FS inversion stuff with a 'fake' lock like we use for other things like workqueues etc. I think this should be possible which allows reducing the 'irq' states and will reduce the amount of __bfs() lookups we do. Removing the 1 IRQ state results in 4 less __bfs() walks per dependency, improving lockdep performance. And by moving this annotation out of the lockdep code it becomes easier for the mm people to extend. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: iamjoonsoo.kim@lge.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Heiko Carstens | 167d0f258f |
mm: take memory hotplug lock within numa_zonelist_order_handler()
Andre Wild reported the following warning: WARNING: CPU: 2 PID: 1205 at kernel/cpu.c:240 lockdep_assert_cpus_held+0x4c/0x60 Modules linked in: CPU: 2 PID: 1205 Comm: bash Not tainted 4.13.0-rc2-00022-gfd2b2c57ec20 #10 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) task: 00000000701d8100 task.stack: 0000000073594000 Krnl PSW : 0704f00180000000 0000000000145e24 (lockdep_assert_cpus_held+0x4c/0x60) ... Call Trace: lockdep_assert_cpus_held+0x42/0x60) stop_machine_cpuslocked+0x62/0xf0 build_all_zonelists+0x92/0x150 numa_zonelist_order_handler+0x102/0x150 proc_sys_call_handler.isra.12+0xda/0x118 proc_sys_write+0x34/0x48 __vfs_write+0x3c/0x178 vfs_write+0xbc/0x1a0 SyS_write+0x66/0xc0 system_call+0xc4/0x2b0 locks held by bash/1205: #0: (sb_writers#4){.+.+.+}, at: vfs_write+0xa6/0x1a0 #1: (zl_order_mutex){+.+...}, at: numa_zonelist_order_handler+0x44/0x150 #2: (zonelists_mutex){+.+...}, at: numa_zonelist_order_handler+0xf4/0x150 Last Breaking-Event-Address: lockdep_assert_cpus_held+0x48/0x60 This can be easily triggered with e.g. echo n > /proc/sys/vm/numa_zonelist_order In commit |
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Michal Hocko | dcda9b0471 |
mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Thomas Gleixner | 3f906ba236 |
mm/memory-hotplug: switch locking to a percpu rwsem
Andrey reported a potential deadlock with the memory hotplug lock and the cpu hotplug lock. The reason is that memory hotplug takes the memory hotplug lock and then calls stop_machine() which calls get_online_cpus(). That's the reverse lock order to get_online_cpus(); get_online_mems(); in mm/slub_common.c The problem has been there forever. The reason why this was never reported is that the cpu hotplug locking had this homebrewn recursive reader writer semaphore construct which due to the recursion evaded the full lock dep coverage. The memory hotplug code copied that construct verbatim and therefor has similar issues. Three steps to fix this: 1) Convert the memory hotplug locking to a per cpu rwsem so the potential issues get reported proper by lockdep. 2) Lock the online cpus in mem_hotplug_begin() before taking the memory hotplug rwsem and use stop_machine_cpuslocked() in the page_alloc code to avoid recursive locking. 3) The cpu hotpluck locking in #2 causes a recursive locking of the cpu hotplug lock via __offline_pages() -> lru_add_drain_all(). Solve this by invoking lru_add_drain_all_cpuslocked() instead. Link: http://lkml.kernel.org/r/20170704093421.506836322@linutronix.de Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Rasmus Villemoes | b002529d25 |
mm/page_alloc.c: eliminate unsigned confusion in __rmqueue_fallback
Since current_order starts as MAX_ORDER-1 and is then only decremented, the second half of the loop condition seems superfluous. However, if order is 0, we may decrement current_order past 0, making it UINT_MAX. This is obviously too subtle ([1], [2]). Since we need to add some comment anyway, change the two variables to signed, making the counting-down for loop look more familiar, and apparently also making gcc generate slightly smaller code. [1] https://lkml.org/lkml/2016/6/20/493 [2] https://lkml.org/lkml/2017/6/19/345 [akpm@linux-foundation.org: fix up reject fixupping] Link: http://lkml.kernel.org/r/20170621185529.2265-1-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reported-by: Hao Lee <haolee.swjtu@gmail.com> Acked-by: Wei Yang <weiyang@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 7a8f58f391 |
mm, page_alloc: fallback to smallest page when not stealing whole pageblock
Since commit
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Michal Hocko | f70029bbaa |
mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
Commit
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Johannes Weiner | 385386cff4 |
mm: vmstat: move slab statistics from zone to node counters
Patch series "mm: per-lruvec slab stats" Josef is working on a new approach to balancing slab caches and the page cache. For this to work, he needs slab cache statistics on the lruvec level. These patches implement that by adding infrastructure that allows updating and reading generic VM stat items per lruvec, then switches some existing VM accounting sites, including the slab accounting ones, to this new cgroup-aware API. I'll follow up with more patches on this, because there is actually substantial simplification that can be done to the memory controller when we replace private memcg accounting with making the existing VM accounting sites cgroup-aware. But this is enough for Josef to base his slab reclaim work on, so here goes. This patch (of 5): To re-implement slab cache vs. page cache balancing, we'll need the slab counters at the lruvec level, which, ever since lru reclaim was moved from the zone to the node, is the intersection of the node, not the zone, and the memcg. We could retain the per-zone counters for when the page allocator dumps its memory information on failures, and have counters on both levels - which on all but NUMA node 0 is usually redundant. But let's keep it simple for now and just move them. If anybody complains we can restore the per-zone counters. [hannes@cmpxchg.org: fix oops] Link: http://lkml.kernel.org/r/20170605183511.GA8915@cmpxchg.org Link: http://lkml.kernel.org/r/20170530181724.27197-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 04ec6264f2 |
mm, page_alloc: pass preferred nid instead of zonelist to allocator
The main allocator function __alloc_pages_nodemask() takes a zonelist pointer as one of its parameters. All of its callers directly or indirectly obtain the zonelist via node_zonelist() using a preferred node id and gfp_mask. We can make the code a bit simpler by doing the zonelist lookup in __alloc_pages_nodemask(), passing it a preferred node id instead (gfp_mask is already another parameter). There are some code size benefits thanks to removal of inlined node_zonelist(): bloat-o-meter add/remove: 2/2 grow/shrink: 4/36 up/down: 399/-1351 (-952) This will also make things simpler if we proceed with converting cpusets to zonelists. Link: http://lkml.kernel.org/r/20170517081140.30654-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 902b62810a |
mm, page_alloc: fix more premature OOM due to race with cpuset update
I would like to stress that this patchset aims to fix issues and cleanup
the code *within the existing documented semantics*, i.e. patch 1
ignores mempolicy restrictions if the set of allowed nodes has no
intersection with set of nodes allowed by cpuset. I believe discussing
potential changes of the semantics can be better done once we have a
baseline with no known bugs of the current semantics.
I've recently summarized the cpuset/mempolicy issues in a LSF/MM
proposal [1] and the discussion itself [2]. I've been trying to rewrite
the handling as proposed, with the idea that changing semantics to make
all mempolicies static wrt cpuset updates (and discarding the relative
and default modes) can be tried on top, as there's a high risk of being
rejected/reverted because somebody might still care about the removed
modes.
However I haven't yet figured out how to properly:
1) make mempolicies swappable instead of rebinding in place. I thought
mbind() already works that way and uses refcounting to avoid
use-after-free of the old policy by a parallel allocation, but turns
out true refcounting is only done for shared (shmem) mempolicies, and
the actual protection for mbind() comes from mmap_sem. Extending the
refcounting means more overhead in allocator hot path. Also swapping
whole mempolicies means that we have to allocate the new ones, which
can fail, and reverting of the partially done work also means
allocating (note that mbind() doesn't care and will just leave part
of the range updated and part not updated when returning -ENOMEM...).
2) make cpuset's task->mems_allowed also swappable (after converting it
from nodemask to zonelist, which is the easy part) for mostly the
same reasons.
The good news is that while trying to do the above, I've at least
figured out how to hopefully close the remaining premature OOM's, and do
a buch of cleanups on top, removing quite some of the code that was also
supposed to prevent the cpuset update races, but doesn't work anymore
nowadays. This should fix the most pressing concerns with this topic
and give us a better baseline before either proceeding with the original
proposal, or pushing a change of semantics that removes the problem 1)
above. I'd be then fine with trying to change the semantic first and
rewrite later.
Patchset has been tested with the LTP cpuset01 stress test.
[1] https://lkml.kernel.org/r/4c44a589-5fd8-08d0-892c-e893bb525b71@suse.cz
[2] https://lwn.net/Articles/717797/
[3] https://marc.info/?l=linux-mm&m=149191957922828&w=2
This patch (of 6):
Commit
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Matthias Kaehlcke | d73d3c9f69 |
mm/page_alloc.c: mark bad_range() and meminit_pfn_in_nid() as __maybe_unused
The functions are not used in some configurations. Adding the attribute fixes the following warnings when building with clang: mm/page_alloc.c:409:19: error: function 'bad_range' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] mm/page_alloc.c:1106:30: error: unused function 'meminit_pfn_in_nid' [-Werror,-Wunused-function] Link: http://lkml.kernel.org/r/20170518182030.165633-1-mka@chromium.org Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | 9017217b6f |
mm: adaptive hash table scaling
Allow hash tables to scale with memory but at slower pace, when HASH_ADAPT is provided every time memory quadruples the sizes of hash tables will only double instead of quadrupling as well. This algorithm starts working only when memory size reaches a certain point, currently set to 64G. This is example of dentry hash table size, before and after four various memory configurations: MEMORY SCALE HASH_SIZE old new old new 8G 13 13 8M 8M 16G 13 13 16M 16M 32G 13 13 32M 32M 64G 13 13 64M 64M 128G 13 14 128M 64M 256G 13 14 256M 128M 512G 13 15 512M 128M 1024G 13 15 1024M 256M 2048G 13 16 2048M 256M 4096G 13 16 4096M 512M 8192G 13 17 8192M 512M 16384G 13 17 16384M 1024M 32768G 13 18 32768M 1024M 65536G 13 18 65536M 2048M The effect of this change on runtime is undetectable as filesystem growth is not proportional to machine memory size as is currently assumed. The change effects only large memory machine. Additional tuning might be needed, but that can be done by the clients of the kmem_cache_create interface, not the generic cache allocator itself. The adaptive hashing is disabled on 32 bit systems to avoid confusion of whether base should be different for smaller systems, and to avoid overflows. [mhocko@suse.com: drop HASH_ADAPT] Link: http://lkml.kernel.org/r/20170509094607.GG6481@dhcp22.suse.cz [pasha.tatashin@oracle.com: UL -> ULL fix] Link: http://lkml.kernel.org/r/1495300013-653283-2-git-send-email-pasha.tatashin@oracle.com [pasha.tatashin@oracle.com: disable adaptive hash on 32 bit systems] Link: http://lkml.kernel.org/r/1495469329-755807-2-git-send-email-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/1488432825-92126-5-git-send-email-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Babu Moger <babu.moger@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Pavel Tatashin | 3749a8f008 |
mm: zero hash tables in allocator
Add a new flag HASH_ZERO which when provided grantees that the hash table that is returned by alloc_large_system_hash() is zeroed. In most cases that is what is needed by the caller. Use page level allocator's __GFP_ZERO flags to zero the memory. It is using memset() which is efficient method to zero memory and is optimized for most platforms. Link: http://lkml.kernel.org/r/1488432825-92126-3-git-send-email-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Babu Moger <babu.moger@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 2d070eab2e |
mm: consider zone which is not fully populated to have holes
__pageblock_pfn_to_page has two users currently, set_zone_contiguous which checks whether the given zone contains holes and pageblock_pfn_to_page which then carefully returns a first valid page from the given pfn range for the given zone. This doesn't handle zones which are not fully populated though. Memory pageblocks can be offlined or might not have been onlined yet. In such a case the zone should be considered to have holes otherwise pfn walkers can touch and play with offline pages. Current callers of pageblock_pfn_to_page in compaction seem to work properly right now because they only isolate PageBuddy (isolate_freepages_block) or PageLRU resp. __PageMovable (isolate_migratepages_block) which will be always false for these pages. It would be safer to skip these pages altogether, though. In order to do this patch adds a new memory section state (SECTION_IS_ONLINE) which is set in memory_present (during boot time) or in online_pages_range during the memory hotplug. Similarly offline_mem_sections clears the bit and it is called when the memory range is offlined. pfn_to_online_page helper is then added which check the mem section and only returns a page if it is onlined already. Use the new helper in __pageblock_pfn_to_page and skip the whole page block in such a case. [mhocko@suse.com: check valid section number in pfn_to_online_page (Vlastimil), mark sections online after all struct pages are initialized in online_pages_range (Vlastimil)] Link: http://lkml.kernel.org/r/20170518164210.GD18333@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170515085827.16474-8-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | dc0bbf3b7f |
mm: remove return value from init_currently_empty_zone
Patch series "mm: make movable onlining suck less", v4. Movable onlining is a real hack with many downsides - mainly reintroduction of lowmem/highmem issues we used to have on 32b systems - but it is the only way to make the memory hotremove more reliable which is something that people are asking for. The current semantic of memory movable onlinening is really cumbersome, however. The main reason for this is that the udev driven approach is basically unusable because udev races with the memory probing while only the last memory block or the one adjacent to the existing zone_movable are allowed to be onlined movable. In short the criterion for the successful online_movable changes under udev's feet. A reliable udev approach would require a 2 phase approach where the first successful movable online would have to check all the previous blocks and online them in descending order. This is hard to be considered sane. This patchset aims at making the onlining semantic more usable. First of all it allows to online memory movable as long as it doesn't clash with the existing ZONE_NORMAL. That means that ZONE_NORMAL and ZONE_MOVABLE cannot overlap. Currently I preserve the original ordering semantic so the zone always precedes the movable zone but I have plans to remove this restriction in future because it is not really necessary. First 3 patches are cleanups which should be ready to be merged right away (unless I have missed something subtle of course). Patch 4 deals with ZONE_DEVICE dependencies down the __add_pages path. Patch 5 deals with implicit assumptions of register_one_node on pgdat initialization. Patches 6-10 deal with offline holes in the zone for pfn walkers. I hope I got all of them right but people familiar with compaction should double check this. Patch 11 is the core of the change. In order to make it easier to review I have tried it to be as minimalistic as possible and the large code removal is moved to patch 14. Patch 12 is a trivial follow up cleanup. Patch 13 fixes sparse warnings and finally patch 14 removes the unused code. I have tested the patches in kvm: # qemu-system-x86_64 -enable-kvm -monitor pty -m 2G,slots=4,maxmem=4G -numa node,mem=1G -numa node,mem=1G ... and then probed the additional memory by (qemu) object_add memory-backend-ram,id=mem1,size=1G (qemu) device_add pc-dimm,id=dimm1,memdev=mem1 Then I have used this simple script to probe the memory block by hand # cat probe_memblock.sh #!/bin/sh BLOCK_NR=$1 # echo $((0x100000000+$BLOCK_NR*(128<<20))) > /sys/devices/system/memory/probe # for i in $(seq 10); do sh probe_memblock.sh $i; done # grep . /sys/devices/system/memory/memory3?/valid_zones 2>/dev/null /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Normal Movable /sys/devices/system/memory/memory35/valid_zones:Normal Movable /sys/devices/system/memory/memory36/valid_zones:Normal Movable /sys/devices/system/memory/memory37/valid_zones:Normal Movable /sys/devices/system/memory/memory38/valid_zones:Normal Movable /sys/devices/system/memory/memory39/valid_zones:Normal Movable The main difference to the original implementation is that all new memblocks can be both online_kernel and online_movable initially because there is no clash obviously. For the comparison the original implementation would have /sys/devices/system/memory/memory33/valid_zones:Normal /sys/devices/system/memory/memory34/valid_zones:Normal /sys/devices/system/memory/memory35/valid_zones:Normal /sys/devices/system/memory/memory36/valid_zones:Normal /sys/devices/system/memory/memory37/valid_zones:Normal /sys/devices/system/memory/memory38/valid_zones:Normal /sys/devices/system/memory/memory39/valid_zones:Normal Movable Now # echo online_movable > /sys/devices/system/memory/memory34/state # grep . /sys/devices/system/memory/memory3?/valid_zones 2>/dev/null /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable /sys/devices/system/memory/memory35/valid_zones:Movable /sys/devices/system/memory/memory36/valid_zones:Movable /sys/devices/system/memory/memory37/valid_zones:Movable /sys/devices/system/memory/memory38/valid_zones:Movable /sys/devices/system/memory/memory39/valid_zones:Movable Block 33 can still be online both kernel and movable while all the remaining can be only movable. /proc/zonelist says Node 0, zone Normal pages free 0 min 0 low 0 high 0 spanned 0 present 0 -- Node 0, zone Movable pages free 32753 min 85 low 117 high 149 spanned 32768 present 32768 A new memblock at a lower address will result in a new memblock (32) which will still allow both Normal and Movable. # sh probe_memblock.sh 0 # grep . /sys/devices/system/memory/memory3[2-5]/valid_zones 2>/dev/null /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable /sys/devices/system/memory/memory35/valid_zones:Movable and online_kernel will convert it to the zone normal properly while 33 can be still onlined both ways. # echo online_kernel > /sys/devices/system/memory/memory32/state # grep . /sys/devices/system/memory/memory3[2-5]/valid_zones 2>/dev/null /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable /sys/devices/system/memory/memory35/valid_zones:Movable /proc/zoneinfo will now tell Node 0, zone Normal pages free 65441 min 165 low 230 high 295 spanned 65536 present 65536 -- Node 0, zone Movable pages free 32740 min 82 low 114 high 146 spanned 32768 present 32768 so both zones have one memblock spanned and present. Onlining 39 should associate this block to the movable zone # echo online > /sys/devices/system/memory/memory39/state /proc/zoneinfo will now tell Node 0, zone Normal pages free 32765 min 80 low 112 high 144 spanned 32768 present 32768 -- Node 0, zone Movable pages free 65501 min 160 low 225 high 290 spanned 196608 present 65536 so we will have a movable zone which spans 6 memblocks, 2 present and 4 representing a hole. Offlining both movable blocks will lead to the zone with no present pages which is the expected behavior I believe. # echo offline > /sys/devices/system/memory/memory39/state # echo offline > /sys/devices/system/memory/memory34/state # grep -A6 "Movable\|Normal" /proc/zoneinfo Node 0, zone Normal pages free 32735 min 90 low 122 high 154 spanned 32768 present 32768 -- Node 0, zone Movable pages free 0 min 0 low 0 high 0 spanned 196608 present 0 As a bonus we will get a nice cleanup in the memory hotplug codebase. This patch (of 16): init_currently_empty_zone doesn't have any error to return yet it is still an int and callers try to be defensive and try to handle potential error. Remove this nonsense and simplify all callers. This patch shouldn't have any visible effect Link: http://lkml.kernel.org/r/20170515085827.16474-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 864b9a393d |
mm: consider memblock reservations for deferred memory initialization sizing
We have seen an early OOM killer invocation on ppc64 systems with
crashkernel=4096M:
kthreadd invoked oom-killer: gfp_mask=0x16040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK), nodemask=7, order=0, oom_score_adj=0
kthreadd cpuset=/ mems_allowed=7
CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.4.68-1.gd7fe927-default #1
Call Trace:
dump_stack+0xb0/0xf0 (unreliable)
dump_header+0xb0/0x258
out_of_memory+0x5f0/0x640
__alloc_pages_nodemask+0xa8c/0xc80
kmem_getpages+0x84/0x1a0
fallback_alloc+0x2a4/0x320
kmem_cache_alloc_node+0xc0/0x2e0
copy_process.isra.25+0x260/0x1b30
_do_fork+0x94/0x470
kernel_thread+0x48/0x60
kthreadd+0x264/0x330
ret_from_kernel_thread+0x5c/0xa4
Mem-Info:
active_anon:0 inactive_anon:0 isolated_anon:0
active_file:0 inactive_file:0 isolated_file:0
unevictable:0 dirty:0 writeback:0 unstable:0
slab_reclaimable:5 slab_unreclaimable:73
mapped:0 shmem:0 pagetables:0 bounce:0
free:0 free_pcp:0 free_cma:0
Node 7 DMA free:0kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:52428800kB managed:110016kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:320kB slab_unreclaimable:4672kB kernel_stack:1152kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
lowmem_reserve[]: 0 0 0 0
Node 7 DMA: 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 0kB
0 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/0
Free swap = 0kB
Total swap = 0kB
819200 pages RAM
0 pages HighMem/MovableOnly
817481 pages reserved
0 pages cma reserved
0 pages hwpoisoned
the reason is that the managed memory is too low (only 110MB) while the
rest of the the 50GB is still waiting for the deferred intialization to
be done. update_defer_init estimates the initial memoty to initialize
to 2GB at least but it doesn't consider any memory allocated in that
range. In this particular case we've had
Reserving 4096MB of memory at 128MB for crashkernel (System RAM: 51200MB)
so the low 2GB is mostly depleted.
Fix this by considering memblock allocations in the initial static
initialization estimation. Move the max_initialise to
reset_deferred_meminit and implement a simple memblock_reserved_memory
helper which iterates all reserved blocks and sums the size of all that
start below the given address. The cumulative size is than added on top
of the initial estimation. This is still not ideal because
reset_deferred_meminit doesn't consider holes and so reservation might
be above the initial estimation whihch we ignore but let's make the
logic simpler until we really need to handle more complicated cases.
Fixes:
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Tetsuo Handa | c288983ddd |
mm/page_alloc.c: make sure OOM victim can try allocations with no watermarks once
Roman Gushchin has reported that the OOM killer can trivially selects next OOM victim when a thread doing memory allocation from page fault path was selected as first OOM victim. allocate invoked oom-killer: gfp_mask=0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null), order=0, oom_score_adj=0 allocate cpuset=/ mems_allowed=0 CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: oom_kill_process+0x219/0x3e0 out_of_memory+0x11d/0x480 __alloc_pages_slowpath+0xc84/0xd40 __alloc_pages_nodemask+0x245/0x260 alloc_pages_vma+0xa2/0x270 __handle_mm_fault+0xca9/0x10c0 handle_mm_fault+0xf3/0x210 __do_page_fault+0x240/0x4e0 trace_do_page_fault+0x37/0xe0 do_async_page_fault+0x19/0x70 async_page_fault+0x28/0x30 ... Out of memory: Kill process 492 (allocate) score 899 or sacrifice child Killed process 492 (allocate) total-vm:2052368kB, anon-rss:1894576kB, file-rss:4kB, shmem-rss:0kB allocate: page allocation failure: order:0, mode:0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null) allocate cpuset=/ mems_allowed=0 CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: __alloc_pages_slowpath+0xd32/0xd40 __alloc_pages_nodemask+0x245/0x260 alloc_pages_vma+0xa2/0x270 __handle_mm_fault+0xca9/0x10c0 handle_mm_fault+0xf3/0x210 __do_page_fault+0x240/0x4e0 trace_do_page_fault+0x37/0xe0 do_async_page_fault+0x19/0x70 async_page_fault+0x28/0x30 ... oom_reaper: reaped process 492 (allocate), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB ... allocate invoked oom-killer: gfp_mask=0x0(), nodemask=(null), order=0, oom_score_adj=0 allocate cpuset=/ mems_allowed=0 CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: oom_kill_process+0x219/0x3e0 out_of_memory+0x11d/0x480 pagefault_out_of_memory+0x68/0x80 mm_fault_error+0x8f/0x190 ? handle_mm_fault+0xf3/0x210 __do_page_fault+0x4b2/0x4e0 trace_do_page_fault+0x37/0xe0 do_async_page_fault+0x19/0x70 async_page_fault+0x28/0x30 ... Out of memory: Kill process 233 (firewalld) score 10 or sacrifice child Killed process 233 (firewalld) total-vm:246076kB, anon-rss:20956kB, file-rss:0kB, shmem-rss:0kB There is a race window that the OOM reaper completes reclaiming the first victim's memory while nothing but mutex_trylock() prevents the first victim from calling out_of_memory() from pagefault_out_of_memory() after memory allocation for page fault path failed due to being selected as an OOM victim. This is a side effect of commit |
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Vlastimil Babka | 499118e966 |
mm: introduce memalloc_noreclaim_{save,restore}
The previous patch ("mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC") has shown that simply setting and clearing PF_MEMALLOC in current->flags can result in wrongly clearing a pre-existing PF_MEMALLOC flag and potentially lead to recursive reclaim. Let's introduce helpers that support proper nesting by saving the previous stat of the flag, similar to the existing memalloc_noio_* and memalloc_nofs_* helpers. Convert existing setting/clearing of PF_MEMALLOC within mm to the new helpers. There are no known issues with the converted code, but the change makes it more robust. Link: http://lkml.kernel.org/r/20170405074700.29871-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Chris Leech <cleech@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Lee Duncan <lduncan@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 62be1511b1 |
mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC
Patch series "more robust PF_MEMALLOC handling" This series aims to unify the setting and clearing of PF_MEMALLOC, which prevents recursive reclaim. There are some places that clear the flag unconditionally from current->flags, which may result in clearing a pre-existing flag. This already resulted in a bug report that Patch 1 fixes (without the new helpers, to make backporting easier). Patch 2 introduces the new helpers, modelled after existing memalloc_noio_* and memalloc_nofs_* helpers, and converts mm core to use them. Patches 3 and 4 convert non-mm code. This patch (of 4): __alloc_pages_direct_compact() sets PF_MEMALLOC to prevent deadlock during page migration by lock_page() (see the comment in __unmap_and_move()). Then it unconditionally clears the flag, which can clear a pre-existing PF_MEMALLOC flag and result in recursive reclaim. This was not a problem until commit |
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Vlastimil Babka | 282722b0d2 |
mm, compaction: restrict async compaction to pageblocks of same migratetype
The migrate scanner in async compaction is currently limited to MIGRATE_MOVABLE pageblocks. This is a heuristic intended to reduce latency, based on the assumption that non-MOVABLE pageblocks are unlikely to contain movable pages. However, with the exception of THP's, most high-order allocations are not movable. Should the async compaction succeed, this increases the chance that the non-MOVABLE allocations will fallback to a MOVABLE pageblock, making the long-term fragmentation worse. This patch attempts to help the situation by changing async direct compaction so that the migrate scanner only scans the pageblocks of the requested migratetype. If it's a non-MOVABLE type and there are such pageblocks that do contain movable pages, chances are that the allocation can succeed within one of such pageblocks, removing the need for a fallback. If that fails, the subsequent sync attempt will ignore this restriction. In testing based on 4.9 kernel with stress-highalloc from mmtests configured for order-4 GFP_KERNEL allocations, this patch has reduced the number of unmovable allocations falling back to movable pageblocks by 30%. The number of movable allocations falling back is reduced by 12%. Link: http://lkml.kernel.org/r/20170307131545.28577-8-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 02aa0cdd72 |
mm, page_alloc: count movable pages when stealing from pageblock
When stealing pages from pageblock of a different migratetype, we count how many free pages were stolen, and change the pageblock's migratetype if more than half of the pageblock was free. This might be too conservative, as there might be other pages that are not free, but were allocated with the same migratetype as our allocation requested. While we cannot determine the migratetype of allocated pages precisely (at least without the page_owner functionality enabled), we can count pages that compaction would try to isolate for migration - those are either on LRU or __PageMovable(). The rest can be assumed to be MIGRATE_RECLAIMABLE or MIGRATE_UNMOVABLE, which we cannot easily distinguish. This counting can be done as part of free page stealing with little additional overhead. The page stealing code is changed so that it considers free pages plus pages of the "good" migratetype for the decision whether to change pageblock's migratetype. The result should be more accurate migratetype of pageblocks wrt the actual pages in the pageblocks, when stealing from semi-occupied pageblocks. This should help the efficiency of page grouping by mobility. In testing based on 4.9 kernel with stress-highalloc from mmtests configured for order-4 GFP_KERNEL allocations, this patch has reduced the number of unmovable allocations falling back to movable pageblocks by 47%. The number of movable allocations falling back to other pageblocks are increased by 55%, but these events don't cause permanent fragmentation, so the tradeoff should be positive. Later patches also offset the movable fallback increase to some extent. [akpm@linux-foundation.org: merge fix] Link: http://lkml.kernel.org/r/20170307131545.28577-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka | 3bc48f96cf |
mm, page_alloc: split smallest stolen page in fallback
The __rmqueue_fallback() function is called when there's no free page of requested migratetype, and we need to steal from a different one. There are various heuristics to make this event infrequent and reduce permanent fragmentation. The main one is to try stealing from a pageblock that has the most free pages, and possibly steal them all at once and convert the whole pageblock. Precise searching for such pageblock would be expensive, so instead the heuristics walks the free lists from MAX_ORDER down to requested order and assumes that the block with highest-order free page is likely to also have the most free pages in total. Chances are that together with the highest-order page, we steal also pages of lower orders from the same block. But then we still split the highest order page. This is wasteful and can contribute to fragmentation instead of avoiding it. This patch thus changes __rmqueue_fallback() to just steal the page(s) and put them on the freelist of the requested migratetype, and only report whether it was successful. Then we pick (and eventually split) the smallest page with __rmqueue_smallest(). This all happens under zone lock, so nobody can steal it from us in the process. This should reduce fragmentation due to fallbacks. At worst we are only stealing a single highest-order page and waste some cycles by moving it between lists and then removing it, but fallback is not exactly hot path so that should not be a concern. As a side benefit the patch removes some duplicate code by reusing __rmqueue_smallest(). [vbabka@suse.cz: fix endless loop in the modified __rmqueue()] Link: http://lkml.kernel.org/r/59d71b35-d556-4fc9-ee2e-1574259282fd@suse.cz Link: http://lkml.kernel.org/r/20170307131545.28577-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | 4c174688ee |
New features for this release:
o Pretty much a full rewrite of the processing of function plugins. i.e. echo do_IRQ:stacktrace > set_ftrace_filter o The rewrite was needed to add plugins to be unique to tracing instances. i.e. mkdir instance/foo; cd instances/foo; echo do_IRQ:stacktrace > set_ftrace_filter The old way was written very hacky. This removes a lot of those hacks. o New "function-fork" tracing option. When set, pids in the set_ftrace_pid will have their children added when the processes with their pids listed in the set_ftrace_pid file forks. o Exposure of "maxactive" for kretprobe in kprobe_events o Allow for builtin init functions to be traced by the function tracer (via the kernel command line). Module init function tracing will come in the next release. o Added more selftests, and have selftests also test in an instance. -----BEGIN PGP SIGNATURE----- iQExBAABCAAbBQJZCRchFBxyb3N0ZWR0QGdvb2RtaXMub3JnAAoJEMm5BfJq2Y3L zuIH/RsLUb8Hj6GmhAvn/tblUDzWyqlXX2h79VVlo/XrWayHYNHnKOmua1WwMZC6 xESXb/AffAc89VWTkKsrwaK7yfRPG6+w8zTZOcFuXSBpqSGG/oey9Fxj5Wqqpche oJ2UY7ngxANAipkP5GxdYTafFSoWhGZGfUUtW+5tAHoFHzqO2lOjO8olbXP69sON kVX/b461S20cVvRe5H/F0klXLSc37Tlp5YznXy4H4V4HcJSN1Fb6/uozOXALZ4se SBpVMWmVVoGJorzj+ic7gVOeohvC8RnR400HbeMVwaI0Lj50noidDj/5Hv8F7T+D h1B8vATNZLFAFUOSHINCBIu6Vj0= =t8mg -----END PGP SIGNATURE----- Merge tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "New features for this release: - Pretty much a full rewrite of the processing of function plugins. i.e. echo do_IRQ:stacktrace > set_ftrace_filter - The rewrite was needed to add plugins to be unique to tracing instances. i.e. mkdir instance/foo; cd instances/foo; echo do_IRQ:stacktrace > set_ftrace_filter The old way was written very hacky. This removes a lot of those hacks. - New "function-fork" tracing option. When set, pids in the set_ftrace_pid will have their children added when the processes with their pids listed in the set_ftrace_pid file forks. - Exposure of "maxactive" for kretprobe in kprobe_events - Allow for builtin init functions to be traced by the function tracer (via the kernel command line). Module init function tracing will come in the next release. - Added more selftests, and have selftests also test in an instance" * tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits) ring-buffer: Return reader page back into existing ring buffer selftests: ftrace: Allow some event trigger tests to run in an instance selftests: ftrace: Have some basic tests run in a tracing instance too selftests: ftrace: Have event tests also run in an tracing instance selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances selftests: ftrace: Allow some tests to be run in a tracing instance tracing/ftrace: Allow for instances to trigger their own stacktrace probes tracing/ftrace: Allow for the traceonoff probe be unique to instances tracing/ftrace: Enable snapshot function trigger to work with instances tracing/ftrace: Allow instances to have their own function probes tracing/ftrace: Add a better way to pass data via the probe functions ftrace: Dynamically create the probe ftrace_ops for the trace_array tracing: Pass the trace_array into ftrace_probe_ops functions tracing: Have the trace_array hold the list of registered func probes ftrace: If the hash for a probe fails to update then free what was initialized ftrace: Have the function probes call their own function ftrace: Have each function probe use its own ftrace_ops ftrace: Have unregister_ftrace_function_probe_func() return a value ftrace: Add helper function ftrace_hash_move_and_update_ops() ftrace: Remove data field from ftrace_func_probe structure ... |
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Tetsuo Handa | 0f7896f12b |
mm, page_alloc: remove debug_guardpage_minorder() test in warn_alloc()
Commit
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Vinayak Menon | bd33ef3681 |
mm: enable page poisoning early at boot
On SPARSEMEM systems page poisoning is enabled after buddy is up, because of the dependency on page extension init. This causes the pages released by free_all_bootmem not to be poisoned. This either delays or misses the identification of some issues because the pages have to undergo another cycle of alloc-free-alloc for any corruption to be detected. Enable page poisoning early by getting rid of the PAGE_EXT_DEBUG_POISON flag. Since all the free pages will now be poisoned, the flag need not be verified before checking the poison during an alloc. [vinmenon@codeaurora.org: fix Kconfig] Link: http://lkml.kernel.org/r/1490878002-14423-1-git-send-email-vinmenon@codeaurora.org Link: http://lkml.kernel.org/r/1490358246-11001-1-git-send-email-vinmenon@codeaurora.org Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Acked-by: Laura Abbott <labbott@redhat.com> Tested-by: Laura Abbott <labbott@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Johannes Weiner | 8225196341 |
mm: page_alloc: __GFP_NOWARN shouldn't suppress stall warnings
__GFP_NOWARN, which is usually added to avoid warnings from callsites that expect to fail and have fallbacks, currently also suppresses allocation stall warnings. These trigger when an allocation is stuck inside the allocator for 10 seconds or longer. But there is no class of allocations that can get legitimately stuck in the allocator for this long. This always indicates a problem. Always emit stall warnings. Restrict __GFP_NOWARN to alloc failures. Link: http://lkml.kernel.org/r/20170125181150.GA16398@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 7dea19f9ee |
mm: introduce memalloc_nofs_{save,restore} API
GFP_NOFS context is used for the following 5 reasons currently: - to prevent from deadlocks when the lock held by the allocation context would be needed during the memory reclaim - to prevent from stack overflows during the reclaim because the allocation is performed from a deep context already - to prevent lockups when the allocation context depends on other reclaimers to make a forward progress indirectly - just in case because this would be safe from the fs POV - silence lockdep false positives Unfortunately overuse of this allocation context brings some problems to the MM. Memory reclaim is much weaker (especially during heavy FS metadata workloads), OOM killer cannot be invoked because the MM layer doesn't have enough information about how much memory is freeable by the FS layer. In many cases it is far from clear why the weaker context is even used and so it might be used unnecessarily. We would like to get rid of those as much as possible. One way to do that is to use the flag in scopes rather than isolated cases. Such a scope is declared when really necessary, tracked per task and all the allocation requests from within the context will simply inherit the GFP_NOFS semantic. Not only this is easier to understand and maintain because there are much less problematic contexts than specific allocation requests, this also helps code paths where FS layer interacts with other layers (e.g. crypto, security modules, MM etc...) and there is no easy way to convey the allocation context between the layers. Introduce memalloc_nofs_{save,restore} API to control the scope of GFP_NOFS allocation context. This is basically copying memalloc_noio_{save,restore} API we have for other restricted allocation context GFP_NOIO. The PF_MEMALLOC_NOFS flag already exists and it is just an alias for PF_FSTRANS which has been xfs specific until recently. There are no more PF_FSTRANS users anymore so let's just drop it. PF_MEMALLOC_NOFS is now checked in the MM layer and drops __GFP_FS implicitly same as PF_MEMALLOC_NOIO drops __GFP_IO. memalloc_noio_flags is renamed to current_gfp_context because it now cares about both PF_MEMALLOC_NOFS and PF_MEMALLOC_NOIO contexts. Xfs code paths preserve their semantic. kmem_flags_convert() doesn't need to evaluate the flag anymore. This patch shouldn't introduce any functional changes. Let's hope that filesystems will drop direct GFP_NOFS (resp. ~__GFP_FS) usage as much as possible and only use a properly documented memalloc_nofs_{save,restore} checkpoints where they are appropriate. [akpm@linux-foundation.org: fix comment typo, reflow comment] Link: http://lkml.kernel.org/r/20170306131408.9828-5-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Brian Foster <bfoster@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Xishi Qiu | a6ffdc0784 |
mm: use is_migrate_highatomic() to simplify the code
Introduce two helpers, is_migrate_highatomic() and is_migrate_highatomic_page(). Simplify the code, no functional changes. [akpm@linux-foundation.org: use static inlines rather than macros, per mhocko] Link: http://lkml.kernel.org/r/58B94F15.6060606@huawei.com Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Johannes Weiner | 491d79ae77 |
mm: remove unnecessary back-off function when retrying page reclaim
The backoff mechanism is not needed. If we have MAX_RECLAIM_RETRIES loops without progress, we'll OOM anyway; backing off might cut one or two iterations off that in the rare OOM case. If we have intermittent success reclaiming a few pages, the backoff function gets reset also, and so is of little help in these scenarios. We might want a backoff function for when there IS progress, but not enough to be satisfactory. But this isn't that. Remove it. Link: http://lkml.kernel.org/r/20170228214007.5621-10-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Johannes Weiner | c822f6223d |
mm: delete NR_PAGES_SCANNED and pgdat_reclaimable()
NR_PAGES_SCANNED counts number of pages scanned since the last page free event in the allocator. This was used primarily to measure the reclaimability of zones and nodes, and determine when reclaim should give up on them. In that role, it has been replaced in the preceding patches by a different mechanism. Being implemented as an efficient vmstat counter, it was automatically exported to userspace as well. It's however unlikely that anyone outside the kernel is using this counter in any meaningful way. Remove the counter and the unused pgdat_reclaimable(). Link: http://lkml.kernel.org/r/20170228214007.5621-8-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Johannes Weiner | c73322d098 |
mm: fix 100% CPU kswapd busyloop on unreclaimable nodes
Patch series "mm: kswapd spinning on unreclaimable nodes - fixes and
cleanups".
Jia reported a scenario in which the kswapd of a node indefinitely spins
at 100% CPU usage. We have seen similar cases at Facebook.
The kernel's current method of judging its ability to reclaim a node (or
whether to back off and sleep) is based on the amount of scanned pages
in proportion to the amount of reclaimable pages. In Jia's and our
scenarios, there are no reclaimable pages in the node, however, and the
condition for backing off is never met. Kswapd busyloops in an attempt
to restore the watermarks while having nothing to work with.
This series reworks the definition of an unreclaimable node based not on
scanning but on whether kswapd is able to actually reclaim pages in
MAX_RECLAIM_RETRIES (16) consecutive runs. This is the same criteria
the page allocator uses for giving up on direct reclaim and invoking the
OOM killer. If it cannot free any pages, kswapd will go to sleep and
leave further attempts to direct reclaim invocations, which will either
make progress and re-enable kswapd, or invoke the OOM killer.
Patch #1 fixes the immediate problem Jia reported, the remainder are
smaller fixlets, cleanups, and overall phasing out of the old method.
Patch #6 is the odd one out. It's a nice cleanup to get_scan_count(),
and directly related to #5, but in itself not relevant to the series.
If the whole series is too ambitious for 4.11, I would consider the
first three patches fixes, the rest cleanups.
This patch (of 9):
Jia He reports a problem with kswapd spinning at 100% CPU when
requesting more hugepages than memory available in the system:
$ echo 4000 >/proc/sys/vm/nr_hugepages
top - 13:42:59 up 3:37, 1 user, load average: 1.09, 1.03, 1.01
Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 12.5 sy, 0.0 ni, 85.5 id, 2.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem: 31371520 total, 30915136 used, 456384 free, 320 buffers
KiB Swap: 6284224 total, 115712 used, 6168512 free. 48192 cached Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
76 root 20 0 0 0 0 R 100.0 0.000 217:17.29 kswapd3
At that time, there are no reclaimable pages left in the node, but as
kswapd fails to restore the high watermarks it refuses to go to sleep.
Kswapd needs to back away from nodes that fail to balance. Up until
commit
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Linus Torvalds | c58d4055c0 |
A reasonably busy cycle for documentation this time around. There is a new
guide for user-space API documents, rather sparsely populated at the moment, but it's a start. Markus improved the infrastructure for converting diagrams. Mauro has converted much of the USB documentation over to RST. Plus the usual set of fixes, improvements, and tweaks. There's a bit more than the usual amount of reaching out of Documentation/ to fix comments elsewhere in the tree; I have acks for those where I could get them. -----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJZB1elAAoJEI3ONVYwIuV6wUIQAJSM/4rNdj6z+GXeWhRfbsOo vqqVYluvXQIJaaqdsy9dgcfThhOXWYsPyVF6Xd+bDJpwF3BMZYbX1CI1Mo3kRD+7 9+Pf68cYSHRoU3l/sFI8q0zfKbHtmFteIvnRQoFtRaExqgTR8glUfxNDyN9XuNAZ 3naS4qMZivM4gjMcSpIB/wFOQpV+6qVIs6VTFLdCC8wodT3W/Wmb+bqrCVJ0twbB t8jJeYHt2wsiTdqrKU+VilAUAZ1Lby+DNfeWrO18rC1ohktPyUzOGg8JmTKUBpVO qj1OJwD6abuaNh/J9bXsh8u0OrVrBKWjVrhq9IFYDlm92fu3Bgr6YeoaVPEpcklt jdlgZnWs9/oXa6d32aMc9F7mP9a0Q1qikFTYINhaHQZCb4VDRuQ9hCSuqWm5jlVy lmVAoxLa0zSdOoXaYuO3HC99ku1cIn814CXMDz/IwKXkqUCV+zl+H3AGkvxGyQ5M eblw2TnQnc6e1LRcxt5bgpFR1JYMbCJhu0U5XrNFueQV8ReB15dvL7h4y21dWJKF 2Sr83rwfG1rpZQiSqCjOXxIzuXbEGH3+a+zCDV5IHhQRt/VNDOt2hgmcyucSSJ5h 5GRFYgTlGvoT/6LdIT39QooHB+4tSDRtEQ6lh0q2ZtVV2rfG/I6/PR5sUbWM65SN vAfctRm2afHLhdonSX5O =41m+ -----END PGP SIGNATURE----- Merge tag 'docs-4.12' of git://git.lwn.net/linux Pull documentation update from Jonathan Corbet: "A reasonably busy cycle for documentation this time around. There is a new guide for user-space API documents, rather sparsely populated at the moment, but it's a start. Markus improved the infrastructure for converting diagrams. Mauro has converted much of the USB documentation over to RST. Plus the usual set of fixes, improvements, and tweaks. There's a bit more than the usual amount of reaching out of Documentation/ to fix comments elsewhere in the tree; I have acks for those where I could get them" * tag 'docs-4.12' of git://git.lwn.net/linux: (74 commits) docs: Fix a couple typos docs: Fix a spelling error in vfio-mediated-device.txt docs: Fix a spelling error in ioctl-number.txt MAINTAINERS: update file entry for HSI subsystem Documentation: allow installing man pages to a user defined directory Doc/PM: Sync with intel_powerclamp code behavior zr364xx.rst: usb/devices is now at /sys/kernel/debug/ usb.rst: move documentation from proc_usb_info.txt to USB ReST book convert philips.txt to ReST and add to media docs docs-rst: usb: update old usbfs-related documentation arm: Documentation: update a path name docs: process/4.Coding.rst: Fix a couple of document refs docs-rst: fix usb cross-references usb: gadget.h: be consistent at kernel doc macros usb: composite.h: fix two warnings when building docs usb: get rid of some ReST doc build errors usb.rst: get rid of some Sphinx errors usb/URB.txt: convert to ReST and update it usb/persist.txt: convert to ReST and add to driver-api book usb/hotplug.txt: convert to ReST and add to driver-api book ... |
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Mel Gorman | d34b0733b4 |
Revert "mm, page_alloc: only use per-cpu allocator for irq-safe requests"
This reverts commit
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Michal Hocko | ce612879dd |
mm: move pcp and lru-pcp draining into single wq
We currently have 2 specific WQ_RECLAIM workqueues in the mm code. vmstat_wq for updating pcp stats and lru_add_drain_wq dedicated to drain per cpu lru caches. This seems more than necessary because both can run on a single WQ. Both do not block on locks requiring a memory allocation nor perform any allocations themselves. We will save one rescuer thread this way. On the other hand drain_all_pages() queues work on the system wq which doesn't have rescuer and so this depend on memory allocation (when all workers are stuck allocating and new ones cannot be created). Initially we thought this would be more of a theoretical problem but Hugh Dickins has reported: : 4.11-rc has been giving me hangs after hours of swapping load. At : first they looked like memory leaks ("fork: Cannot allocate memory"); : but for no good reason I happened to do "cat /proc/sys/vm/stat_refresh" : before looking at /proc/meminfo one time, and the stat_refresh stuck : in D state, waiting for completion of flush_work like many kworkers. : kthreadd waiting for completion of flush_work in drain_all_pages(). This worker should be using WQ_RECLAIM as well in order to guarantee a forward progress. We can reuse the same one as for lru draining and vmstat. Link: http://lkml.kernel.org/r/20170307131751.24936-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Tested-by: Yang Li <pku.leo@gmail.com> Tested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Polakov | 1f06b81aea |
mm/page_alloc.c: fix print order in show_free_areas()
Fixes:
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Steven Rostedt (VMware) | b80f0f6c9e |
ftrace: Have init/main.c call ftrace directly to free init memory
Relying on free_reserved_area() to call ftrace to free init memory proved to not be sufficient. The issue is that on x86, when debug_pagealloc is enabled, the init memory is not freed, but simply set as not present. Since ftrace was uninformed of this, starting function tracing still tries to update pages that are not present according to the page tables, causing ftrace to bug, as well as killing the kernel itself. Instead of relying on free_reserved_area(), have init/main.c call ftrace directly just before it frees the init memory. Then it needs to use __init_begin and __init_end to know where the init memory location is. Looking at all archs (and testing what I can), it appears that this should work for each of them. Reported-by: kernel test robot <xiaolong.ye@intel.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
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mchehab@s-opensource.com | 0e056eb553 |
kernel-api.rst: fix a series of errors when parsing C files
./lib/string.c:134: WARNING: Inline emphasis start-string without end-string. ./mm/filemap.c:522: WARNING: Inline interpreted text or phrase reference start-string without end-string. ./mm/filemap.c:1283: ERROR: Unexpected indentation. ./mm/filemap.c:3003: WARNING: Inline interpreted text or phrase reference start-string without end-string. ./mm/vmalloc.c:1544: WARNING: Inline emphasis start-string without end-string. ./mm/page_alloc.c:4245: ERROR: Unexpected indentation. ./ipc/util.c:676: ERROR: Unexpected indentation. ./drivers/pci/irq.c:35: WARNING: Block quote ends without a blank line; unexpected unindent. ./security/security.c:109: ERROR: Unexpected indentation. ./security/security.c:110: WARNING: Definition list ends without a blank line; unexpected unindent. ./block/genhd.c:275: WARNING: Inline strong start-string without end-string. ./block/genhd.c:283: WARNING: Inline strong start-string without end-string. ./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string. ./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string. ./ipc/util.c:477: ERROR: Unknown target name: "s". Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> |