mirror of https://gitee.com/openkylin/linux.git
494 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Pingfan Liu
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276f756d70 |
mm/migrate.c: clean up useless code in migrate_vma_collect_pmd()
Remove unused 'pfn' variable. Link: http://lkml.kernel.org/r/1565167272-21453-1-git-send-email-kernelfans@gmail.com Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Kara <jack@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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4101196b19 |
mm: page cache: store only head pages in i_pages
Transparent Huge Pages are currently stored in i_pages as pointers to consecutive subpages. This patch changes that to storing consecutive pointers to the head page in preparation for storing huge pages more efficiently in i_pages. Large parts of this are "inspired" by Kirill's patch https://lore.kernel.org/lkml/20170126115819.58875-2-kirill.shutemov@linux.intel.com/ Kirill and Huang Ying contributed several fixes. [willy@infradead.org: use compound_nr, squish uninit-var warning] Link: http://lkml.kernel.org/r/20190731210400.7419-1-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Jan Kara <jack@suse.cz> Reviewed-by: Kirill Shutemov <kirill@shutemov.name> Reviewed-by: Song Liu <songliubraving@fb.com> Tested-by: Song Liu <songliubraving@fb.com> Tested-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Tested-by: Qian Cai <cai@lca.pw> Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Song Liu <songliubraving@fb.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 (Oracle)
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d8c6546b1a |
mm: introduce compound_nr()
Replace 1 << compound_order(page) with compound_nr(page). Minor improvements in readability. Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.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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Christoph Hellwig
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7b86ac3371 |
pagewalk: separate function pointers from iterator data
The mm_walk structure currently mixed data and code. Split out the operations vectors into a new mm_walk_ops structure, and while we are changing the API also declare the mm_walk structure inside the walk_page_range and walk_page_vma functions. Based on patch from Linus Torvalds. Link: https://lore.kernel.org/r/20190828141955.22210-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by: Steven Price <steven.price@arm.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Christoph Hellwig
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a520110e4a |
mm: split out a new pagewalk.h header from mm.h
Add a new header for the two handful of users of the walk_page_range / walk_page_vma interface instead of polluting all users of mm.h with it. Link: https://lore.kernel.org/r/20190828141955.22210-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by: Steven Price <steven.price@arm.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Jason Gunthorpe
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daa138a58c |
Merge branch 'odp_fixes' into hmm.git
From rdma.git Jason Gunthorpe says: ==================== This is a collection of general cleanups for ODP to clarify some of the flows around umem creation and use of the interval tree. ==================== The branch is based on v5.3-rc5 due to dependencies, and is being taken into hmm.git due to dependencies in the next patches. * odp_fixes: RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr RDMA/mlx5: Use ib_umem_start instead of umem.address RDMA/core: Make invalidate_range a device operation RDMA/odp: Use kvcalloc for the dma_list and page_list RDMA/odp: Check for overflow when computing the umem_odp end RDMA/odp: Provide ib_umem_odp_release() to undo the allocs RDMA/odp: Split creating a umem_odp from ib_umem_get RDMA/odp: Make the three ways to create a umem_odp clear RMDA/odp: Consolidate umem_odp initialization RDMA/odp: Make it clearer when a umem is an implicit ODP umem RDMA/odp: Iterate over the whole rbtree directly RDMA/odp: Use the common interval tree library instead of generic RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Christoph Hellwig
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9b2ed9cb97 |
mm: remove CONFIG_MIGRATE_VMA_HELPER
CONFIG_MIGRATE_VMA_HELPER guards helpers that are required for proper devic private memory support. Remove the option and just check for CONFIG_DEVICE_PRIVATE instead. Link: https://lore.kernel.org/r/20190814075928.23766-11-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Tested-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Christoph Hellwig
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06d462beb4 |
mm: remove the unused MIGRATE_PFN_DEVICE flag
No one ever checks this flag, and we could easily get that information from the page if needed. Link: https://lore.kernel.org/r/20190814075928.23766-10-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Tested-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Christoph Hellwig
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a7d1f22bb7 |
mm: turn migrate_vma upside down
There isn't any good reason to pass callbacks to migrate_vma. Instead we can just export the three steps done by this function to drivers and let them sequence the operation without callbacks. This removes a lot of boilerplate code as-is, and will allow the drivers to drastically improve code flow and error handling further on. Link: https://lore.kernel.org/r/20190814075928.23766-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Tested-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Ralph Campbell
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7b358c6f12 |
mm/migrate.c: initialize pud_entry in migrate_vma()
When CONFIG_MIGRATE_VMA_HELPER is enabled, migrate_vma() calls
migrate_vma_collect() which initializes a struct mm_walk but didn't
initialize mm_walk.pud_entry. (Found by code inspection) Use a C
structure initialization to make sure it is set to NULL.
Link: http://lkml.kernel.org/r/20190719233225.12243-1-rcampbell@nvidia.com
Fixes:
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Jan Kara
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ebdf4de564 |
mm: migrate: fix reference check race between __find_get_block() and migration
buffer_migrate_page_norefs() can race with bh users in the following
way:
CPU1 CPU2
buffer_migrate_page_norefs()
buffer_migrate_lock_buffers()
checks bh refs
spin_unlock(&mapping->private_lock)
__find_get_block()
spin_lock(&mapping->private_lock)
grab bh ref
spin_unlock(&mapping->private_lock)
move page do bh work
This can result in various issues like lost updates to buffers (i.e.
metadata corruption) or use after free issues for the old page.
This patch closes the race by holding mapping->private_lock while the
mapping is being moved to a new page. Ordinarily, a reference can be
taken outside of the private_lock using the per-cpu BH LRU but the
references are checked and the LRU invalidated if necessary. The
private_lock is held once the references are known so the buffer lookup
slow path will spin on the private_lock. Between the page lock and
private_lock, it should be impossible for other references to be
acquired and updates to happen during the migration.
A user had reported data corruption issues on a distribution kernel with
a similar page migration implementation as mainline. The data
corruption could not be reproduced with this patch applied. A small
number of migration-intensive tests were run and no performance problems
were noted.
[mgorman@techsingularity.net: Changelog, removed tracing]
Link: http://lkml.kernel.org/r/20190718090238.GF24383@techsingularity.net
Fixes:
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Keith Busch
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371096949f |
mm: migrate: remove unused mode argument
migrate_page_move_mapping() doesn't use the mode argument. Remove it and update callers accordingly. Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.com Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Zi Yan <ziy@nvidia.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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Linus Torvalds
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fec88ab0af |
HMM patches for 5.3
Improvements and bug fixes for the hmm interface in the kernel:
- Improve clarity, locking and APIs related to the 'hmm mirror' feature
merged last cycle. In linux-next we now see AMDGPU and nouveau to be
using this API.
- Remove old or transitional hmm APIs. These are hold overs from the past
with no users, or APIs that existed only to manage cross tree conflicts.
There are still a few more of these cleanups that didn't make the merge
window cut off.
- Improve some core mm APIs:
* export alloc_pages_vma() for driver use
* refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
* refactor duplicative driver code into the core dev_pagemap
struct
- Remove hmm wrappers of improved core mm APIs, instead have drivers use
the simplified API directly
- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull HMM updates from Jason Gunthorpe:
"Improvements and bug fixes for the hmm interface in the kernel:
- Improve clarity, locking and APIs related to the 'hmm mirror'
feature merged last cycle. In linux-next we now see AMDGPU and
nouveau to be using this API.
- Remove old or transitional hmm APIs. These are hold overs from the
past with no users, or APIs that existed only to manage cross tree
conflicts. There are still a few more of these cleanups that didn't
make the merge window cut off.
- Improve some core mm APIs:
- export alloc_pages_vma() for driver use
- refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
- refactor duplicative driver code into the core dev_pagemap
struct
- Remove hmm wrappers of improved core mm APIs, instead have drivers
use the simplified API directly
- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits)
mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
mm: remove the HMM config option
mm: sort out the DEVICE_PRIVATE Kconfig mess
mm: simplify ZONE_DEVICE page private data
mm: remove hmm_devmem_add
mm: remove hmm_vma_alloc_locked_page
nouveau: use devm_memremap_pages directly
nouveau: use alloc_page_vma directly
PCI/P2PDMA: use the dev_pagemap internal refcount
device-dax: use the dev_pagemap internal refcount
memremap: provide an optional internal refcount in struct dev_pagemap
memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
memremap: remove the data field in struct dev_pagemap
memremap: add a migrate_to_ram method to struct dev_pagemap_ops
memremap: lift the devmap_enable manipulation into devm_memremap_pages
memremap: pass a struct dev_pagemap to ->kill and ->cleanup
memremap: move dev_pagemap callbacks into a separate structure
memremap: validate the pagemap type passed to devm_memremap_pages
mm: factor out a devm_request_free_mem_region helper
mm: export alloc_pages_vma
...
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Linus Torvalds
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69bf4b6b54 |
Revert "mm: page cache: store only head pages in i_pages"
This reverts commit
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Christoph Hellwig
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25b2995a35 |
mm: remove MEMORY_DEVICE_PUBLIC support
The code hasn't been used since it was added to the tree, and doesn't appear to actually be usable. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Jérôme Glisse
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7269f99993 |
mm/mmu_notifier: use correct mmu_notifier events for each invalidation
This updates each existing invalidation to use the correct mmu notifier event that represent what is happening to the CPU page table. See the patch which introduced the events to see the rational behind this. Link: http://lkml.kernel.org/r/20190326164747.24405-7-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Christian König <christian.koenig@amd.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: John Hubbard <jhubbard@nvidia.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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Jérôme Glisse
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6f4f13e8d9 |
mm/mmu_notifier: contextual information for event triggering invalidation
CPU page table update can happens for many reasons, not only as a result
of a syscall (munmap(), mprotect(), mremap(), madvise(), ...) but also as
a result of kernel activities (memory compression, reclaim, migration,
...).
Users of mmu notifier API track changes to the CPU page table and take
specific action for them. While current API only provide range of virtual
address affected by the change, not why the changes is happening.
This patchset do the initial mechanical convertion of all the places that
calls mmu_notifier_range_init to also provide the default MMU_NOTIFY_UNMAP
event as well as the vma if it is know (most invalidation happens against
a given vma). Passing down the vma allows the users of mmu notifier to
inspect the new vma page protection.
The MMU_NOTIFY_UNMAP is always the safe default as users of mmu notifier
should assume that every for the range is going away when that event
happens. A latter patch do convert mm call path to use a more appropriate
events for each call.
This is done as 2 patches so that no call site is forgotten especialy
as it uses this following coccinelle patch:
%<----------------------------------------------------------------------
@@
identifier I1, I2, I3, I4;
@@
static inline void mmu_notifier_range_init(struct mmu_notifier_range *I1,
+enum mmu_notifier_event event,
+unsigned flags,
+struct vm_area_struct *vma,
struct mm_struct *I2, unsigned long I3, unsigned long I4) { ... }
@@
@@
-#define mmu_notifier_range_init(range, mm, start, end)
+#define mmu_notifier_range_init(range, event, flags, vma, mm, start, end)
@@
expression E1, E3, E4;
identifier I1;
@@
<...
mmu_notifier_range_init(E1,
+MMU_NOTIFY_UNMAP, 0, I1,
I1->vm_mm, E3, E4)
...>
@@
expression E1, E2, E3, E4;
identifier FN, VMA;
@@
FN(..., struct vm_area_struct *VMA, ...) {
<...
mmu_notifier_range_init(E1,
+MMU_NOTIFY_UNMAP, 0, VMA,
E2, E3, E4)
...> }
@@
expression E1, E2, E3, E4;
identifier FN, VMA;
@@
FN(...) {
struct vm_area_struct *VMA;
<...
mmu_notifier_range_init(E1,
+MMU_NOTIFY_UNMAP, 0, VMA,
E2, E3, E4)
...> }
@@
expression E1, E2, E3, E4;
identifier FN;
@@
FN(...) {
<...
mmu_notifier_range_init(E1,
+MMU_NOTIFY_UNMAP, 0, NULL,
E2, E3, E4)
...> }
---------------------------------------------------------------------->%
Applied with:
spatch --all-includes --sp-file mmu-notifier.spatch fs/proc/task_mmu.c --in-place
spatch --sp-file mmu-notifier.spatch --dir kernel/events/ --in-place
spatch --sp-file mmu-notifier.spatch --dir mm --in-place
Link: http://lkml.kernel.org/r/20190326164747.24405-6-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: John Hubbard <jhubbard@nvidia.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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Matthew Wilcox
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5fd4ca2d84 |
mm: page cache: store only head pages in i_pages
Transparent Huge Pages are currently stored in i_pages as pointers to consecutive subpages. This patch changes that to storing consecutive pointers to the head page in preparation for storing huge pages more efficiently in i_pages. Large parts of this are "inspired" by Kirill's patch https://lore.kernel.org/lkml/20170126115819.58875-2-kirill.shutemov@linux.intel.com/ [willy@infradead.org: fix swapcache pages] Link: http://lkml.kernel.org/r/20190324155441.GF10344@bombadil.infradead.org [kirill@shutemov.name: hugetlb stores pages in page cache differently] Link: http://lkml.kernel.org/r/20190404134553.vuvhgmghlkiw2hgl@kshutemo-mobl1 Link: http://lkml.kernel.org/r/20190307153051.18815-1-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Jan Kara <jack@suse.cz> Reviewed-by: Kirill Shutemov <kirill@shutemov.name> Reviewed-and-tested-by: Song Liu <songliubraving@fb.com> Tested-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Tested-by: Qian Cai <cai@lca.pw> Cc: Hugh Dickins <hughd@google.com> Cc: Song Liu <liu.song.a23@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Lars Persson
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d2b2c6dd22 |
mm/migrate.c: add missing flush_dcache_page for non-mapped page migrate
Our MIPS 1004Kc SoCs were seeing random userspace crashes with SIGILL and SIGSEGV that could not be traced back to a userspace code bug. They had all the magic signs of an I/D cache coherency issue. Now recently we noticed that the /proc/sys/vm/compact_memory interface was quite efficient at provoking this class of userspace crashes. Studying the code in mm/migrate.c there is a distinction made between migrating a page that is mapped at the instant of migration and one that is not mapped. Our problem turned out to be the non-mapped pages. For the non-mapped page the code performs a copy of the page content and all relevant meta-data of the page without doing the required D-cache maintenance. This leaves dirty data in the D-cache of the CPU and on the 1004K cores this data is not visible to the I-cache. A subsequent page-fault that triggers a mapping of the page will happily serve the process with potentially stale code. What about ARM then, this bug should have seen greater exposure? Well ARM became immune to this flaw back in 2010, see commit |
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Jan Kara
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f900482da5 |
mm/migrate.c: cleanup expected_page_refs()
Andrea has noted that page migration code propagates page_mapping(page) through the whole migration stack down to migrate_page() function so it seems stupid to then use page_mapping(page) in expected_page_refs() instead of passed down 'mapping' argument. I agree so let's make expected_page_refs() more in line with the rest of the migration stack. Link: http://lkml.kernel.org/r/20190207112314.24872-1-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Suggested-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.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> |
|
|
Wei Yang
|
8bb4e7a2ee |
mm: fix some typos in mm directory
No functional change. Link: http://lkml.kernel.org/r/20190118235123.27843-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mel Gorman
|
806031bb5e |
mm, migrate: immediately fail migration of a page with no migration handler
Pages with no migration handler use a fallback handler which sometimes
works and sometimes persistently retries. A historical example was
blockdev pages but there are others such as odd refcounting when
page->private is used. These are retried multiple times which is
wasteful during compaction so this patch will fail migration faster
unless the caller specifies MIGRATE_SYNC.
This is not expected to help THP allocation success rates but it did
reduce latencies very slightly in some cases.
1-socket thpfioscale
4.20.0 4.20.0
noreserved-v2r15 failfast-v2r15
Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%*
Amean fault-both-3 3839.67 ( 0.00%) 3833.72 ( 0.15%)
Amean fault-both-5 5177.47 ( 0.00%) 4967.15 ( 4.06%)
Amean fault-both-7 7245.03 ( 0.00%) 7139.19 ( 1.46%)
Amean fault-both-12 11534.89 ( 0.00%) 11326.30 ( 1.81%)
Amean fault-both-18 16241.10 ( 0.00%) 16270.70 ( -0.18%)
Amean fault-both-24 19075.91 ( 0.00%) 19839.65 ( -4.00%)
Amean fault-both-30 22712.11 ( 0.00%) 21707.05 ( 4.43%)
Amean fault-both-32 21692.92 ( 0.00%) 21968.16 ( -1.27%)
The 2-socket results are not materially different. Scan rates are
similar as expected.
Link: http://lkml.kernel.org/r/20190118175136.31341-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Anshuman Khandual
|
7ed2c31dab |
mm/hugetlb: distinguish between migratability and movability
Patch series "arm64/mm: Enable HugeTLB migration", v4.
This patch series enables HugeTLB migration support for all supported
huge page sizes at all levels including contiguous bit implementation.
Following HugeTLB migration support matrix has been enabled with this
patch series. All permutations have been tested except for the 16GB.
CONT PTE PMD CONT PMD PUD
-------- --- -------- ---
4K: 64K 2M 32M 1G
16K: 2M 32M 1G
64K: 2M 512M 16G
First the series adds migration support for PUD based huge pages. It
then adds a platform specific hook to query an architecture if a given
huge page size is supported for migration while also providing a default
fallback option preserving the existing semantics which just checks for
(PMD|PUD|PGDIR)_SHIFT macros. The last two patches enables HugeTLB
migration on arm64 and subscribe to this new platform specific hook by
defining an override.
The second patch differentiates between movability and migratability
aspects of huge pages and implements hugepage_movable_supported() which
can then be used during allocation to decide whether to place the huge
page in movable zone or not.
This patch (of 5):
During huge page allocation it's migratability is checked to determine
if it should be placed under movable zones with GFP_HIGHUSER_MOVABLE.
But the movability aspect of the huge page could depend on other factors
than just migratability. Movability in itself is a distinct property
which should not be tied with migratability alone.
This differentiates these two and implements an enhanced movability check
which also considers huge page size to determine if it is feasible to be
placed under a movable zone. At present it just checks for gigantic pages
but going forward it can incorporate other enhanced checks.
Link: http://lkml.kernel.org/r/1545121450-1663-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Mike Kravetz
|
cb6acd01e2 |
hugetlbfs: fix races and page leaks during migration
hugetlb pages should only be migrated if they are 'active'. The
routines set/clear_page_huge_active() modify the active state of hugetlb
pages.
When a new hugetlb page is allocated at fault time, set_page_huge_active
is called before the page is locked. Therefore, another thread could
race and migrate the page while it is being added to page table by the
fault code. This race is somewhat hard to trigger, but can be seen by
strategically adding udelay to simulate worst case scheduling behavior.
Depending on 'how' the code races, various BUG()s could be triggered.
To address this issue, simply delay the set_page_huge_active call until
after the page is successfully added to the page table.
Hugetlb pages can also be leaked at migration time if the pages are
associated with a file in an explicitly mounted hugetlbfs filesystem.
For example, consider a two node system with 4GB worth of huge pages
available. A program mmaps a 2G file in a hugetlbfs filesystem. It
then migrates the pages associated with the file from one node to
another. When the program exits, huge page counts are as follows:
node0
1024 free_hugepages
1024 nr_hugepages
node1
0 free_hugepages
1024 nr_hugepages
Filesystem Size Used Avail Use% Mounted on
nodev 4.0G 2.0G 2.0G 50% /var/opt/hugepool
That is as expected. 2G of huge pages are taken from the free_hugepages
counts, and 2G is the size of the file in the explicitly mounted
filesystem. If the file is then removed, the counts become:
node0
1024 free_hugepages
1024 nr_hugepages
node1
1024 free_hugepages
1024 nr_hugepages
Filesystem Size Used Avail Use% Mounted on
nodev 4.0G 2.0G 2.0G 50% /var/opt/hugepool
Note that the filesystem still shows 2G of pages used, while there
actually are no huge pages in use. The only way to 'fix' the filesystem
accounting is to unmount the filesystem
If a hugetlb page is associated with an explicitly mounted filesystem,
this information in contained in the page_private field. At migration
time, this information is not preserved. To fix, simply transfer
page_private from old to new page at migration time if necessary.
There is a related race with removing a huge page from a file and
migration. When a huge page is removed from the pagecache, the
page_mapping() field is cleared, yet page_private remains set until the
page is actually freed by free_huge_page(). A page could be migrated
while in this state. However, since page_mapping() is not set the
hugetlbfs specific routine to transfer page_private is not called and we
leak the page count in the filesystem.
To fix that, check for this condition before migrating a huge page. If
the condition is detected, return EBUSY for the page.
Link: http://lkml.kernel.org/r/74510272-7319-7372-9ea6-ec914734c179@oracle.com
Link: http://lkml.kernel.org/r/20190212221400.3512-1-mike.kravetz@oracle.com
Fixes:
|
|
|
David Hildenbrand
|
e0a352fabc |
mm: migrate: don't rely on __PageMovable() of newpage after unlocking it
We had a race in the old balloon compaction code before |
|
|
Jan Kara
|
80409c65e2 |
mm: migrate: make buffer_migrate_page_norefs() actually succeed
Currently, buffer_migrate_page_norefs() was constantly failing because
buffer_migrate_lock_buffers() grabbed reference on each buffer. In
fact, there's no reason for buffer_migrate_lock_buffers() to grab any
buffer references as the page is locked during all our operation and
thus nobody can reclaim buffers from the page.
So remove grabbing of buffer references which also makes
buffer_migrate_page_norefs() succeed.
Link: http://lkml.kernel.org/r/20190116131217.7226-1-jack@suse.cz
Fixes:
|
|
|
Mike Kravetz
|
ddeaab32a8 |
hugetlbfs: revert "use i_mmap_rwsem for more pmd sharing synchronization"
This reverts
|
|
|
Joel Fernandes (Google)
|
4cf5892495 |
mm: treewide: remove unused address argument from pte_alloc functions
Patch series "Add support for fast mremap".
This series speeds up the mremap(2) syscall by copying page tables at
the PMD level even for non-THP systems. There is concern that the extra
'address' argument that mremap passes to pte_alloc may do something
subtle architecture related in the future that may make the scheme not
work. Also we find that there is no point in passing the 'address' to
pte_alloc since its unused. This patch therefore removes this argument
tree-wide resulting in a nice negative diff as well. Also ensuring
along the way that the enabled architectures do not do anything funky
with the 'address' argument that goes unnoticed by the optimization.
Build and boot tested on x86-64. Build tested on arm64. The config
enablement patch for arm64 will be posted in the future after more
testing.
The changes were obtained by applying the following Coccinelle script.
(thanks Julia for answering all Coccinelle questions!).
Following fix ups were done manually:
* Removal of address argument from pte_fragment_alloc
* Removal of pte_alloc_one_fast definitions from m68k and microblaze.
// Options: --include-headers --no-includes
// Note: I split the 'identifier fn' line, so if you are manually
// running it, please unsplit it so it runs for you.
virtual patch
@pte_alloc_func_def depends on patch exists@
identifier E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
type T2;
@@
fn(...
- , T2 E2
)
{ ... }
@pte_alloc_func_proto_noarg depends on patch exists@
type T1, T2, T3, T4;
identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@
(
- T3 fn(T1, T2);
+ T3 fn(T1);
|
- T3 fn(T1, T2, T4);
+ T3 fn(T1, T2);
)
@pte_alloc_func_proto depends on patch exists@
identifier E1, E2, E4;
type T1, T2, T3, T4;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@
(
- T3 fn(T1 E1, T2 E2);
+ T3 fn(T1 E1);
|
- T3 fn(T1 E1, T2 E2, T4 E4);
+ T3 fn(T1 E1, T2 E2);
)
@pte_alloc_func_call depends on patch exists@
expression E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@
fn(...
-, E2
)
@pte_alloc_macro depends on patch exists@
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
identifier a, b, c;
expression e;
position p;
@@
(
- #define fn(a, b, c) e
+ #define fn(a, b) e
|
- #define fn(a, b) e
+ #define fn(a) e
)
Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Mike Kravetz
|
b43a999005 |
hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
While looking at BUGs associated with invalid huge page map counts, it was
discovered and observed that a huge pte pointer could become 'invalid' and
point to another task's page table. Consider the following:
A task takes a page fault on a shared hugetlbfs file and calls
huge_pte_alloc to get a ptep. Suppose the returned ptep points to a
shared pmd.
Now, another task truncates the hugetlbfs file. As part of truncation, it
unmaps everyone who has the file mapped. If the range being truncated is
covered by a shared pmd, huge_pmd_unshare will be called. For all but the
last user of the shared pmd, huge_pmd_unshare will clear the pud pointing
to the pmd. If the task in the middle of the page fault is not the last
user, the ptep returned by huge_pte_alloc now points to another task's
page table or worse. This leads to bad things such as incorrect page
map/reference counts or invalid memory references.
To fix, expand the use of i_mmap_rwsem as follows:
- i_mmap_rwsem is held in read mode whenever huge_pmd_share is called.
huge_pmd_share is only called via huge_pte_alloc, so callers of
huge_pte_alloc take i_mmap_rwsem before calling. In addition, callers
of huge_pte_alloc continue to hold the semaphore until finished with the
ptep.
- i_mmap_rwsem is held in write mode whenever huge_pmd_unshare is
called.
[mike.kravetz@oracle.com: add explicit check for mapping != null]
Link: http://lkml.kernel.org/r/20181218223557.5202-2-mike.kravetz@oracle.com
Fixes:
|
|
|
Jan Kara
|
ab41ee6879 |
mm: migrate: drop unused argument of migrate_page_move_mapping()
All callers of migrate_page_move_mapping() now pass NULL for 'head' argument. Drop it. Link: http://lkml.kernel.org/r/20181211172143.7358-7-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
89cb0888ca |
mm: migrate: provide buffer_migrate_page_norefs()
Provide a variant of buffer_migrate_page() that also checks whether there are no unexpected references to buffer heads. This function will then be safe to use for block device pages. [akpm@linux-foundation.org: remove EXPORT_SYMBOL(buffer_migrate_page_norefs)] Link: http://lkml.kernel.org/r/20181211172143.7358-5-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
84ade7c15c |
mm: migrate: move migrate_page_lock_buffers()
buffer_migrate_page() is the only caller of migrate_page_lock_buffers() move it close to it and also drop the now unused stub for !CONFIG_BLOCK. Link: http://lkml.kernel.org/r/20181211172143.7358-4-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
cc4f11e69f |
mm: migrate: lock buffers before migrate_page_move_mapping()
Lock buffers before calling into migrate_page_move_mapping() so that that function doesn't have to know about buffers (which is somewhat unexpected anyway) and all the buffer head logic is in buffer_migrate_page(). Link: http://lkml.kernel.org/r/20181211172143.7358-3-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
0b3901b38d |
mm: migration: factor out code to compute expected number of page references
Patch series "mm: migrate: Fix page migration stalls for blkdev pages". This patchset deals with page migration stalls that were reported by our customer due to a block device page that had a bufferhead that was in the bh LRU cache. The patchset modifies the page migration code so that bufferheads are completely handled inside buffer_migrate_page() and then provides a new migration helper for pages with buffer heads that is safe to use even for block device pages and that also deals with bh lrus. This patch (of 6): Factor out function to compute number of expected page references in migrate_page_move_mapping(). Note that we move hpage_nr_pages() and page_has_private() checks from under xas_lock_irq() however this is safe since we hold page lock. [jack@suse.cz: fix expected_page_refs()] Link: http://lkml.kernel.org/r/20181217131710.GB8611@quack2.suse.cz Link: http://lkml.kernel.org/r/20181211172143.7358-2-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
ac46d4f3c4 |
mm/mmu_notifier: use structure for invalidate_range_start/end calls v2
To avoid having to change many call sites everytime we want to add a parameter use a structure to group all parameters for the mmu_notifier invalidate_range_start/end cakks. No functional changes with this patch. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/20181205053628.3210-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> From: Jérôme Glisse <jglisse@redhat.com> Subject: mm/mmu_notifier: use structure for invalidate_range_start/end calls v3 fix build warning in migrate.c when CONFIG_MMU_NOTIFIER=n Link: http://lkml.kernel.org/r/20181213171330.8489-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Hugh Dickins
|
9a1ea439b1 |
mm: put_and_wait_on_page_locked() while page is migrated
Waiting on a page migration entry has used wait_on_page_locked() all along since 2006: but you cannot safely wait_on_page_locked() without holding a reference to the page, and that extra reference is enough to make migrate_page_move_mapping() fail with -EAGAIN, when a racing task faults on the entry before migrate_page_move_mapping() gets there. And that failure is retried nine times, amplifying the pain when trying to migrate a popular page. With a single persistent faulter, migration sometimes succeeds; with two or three concurrent faulters, success becomes much less likely (and the more the page was mapped, the worse the overhead of unmapping and remapping it on each try). This is especially a problem for memory offlining, where the outer level retries forever (or until terminated from userspace), because a heavy refault workload can trigger an endless loop of migration failures. wait_on_page_locked() is the wrong tool for the job. David Herrmann (but was he the first?) noticed this issue in 2014: https://marc.info/?l=linux-mm&m=140110465608116&w=2 Tim Chen started a thread in August 2017 which appears relevant: https://marc.info/?l=linux-mm&m=150275941014915&w=2 where Kan Liang went on to implicate __migration_entry_wait(): https://marc.info/?l=linux-mm&m=150300268411980&w=2 and the thread ended up with the v4.14 commits: |
|
|
Linus Torvalds
|
dad4f140ed |
Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax
Pull XArray conversion from Matthew Wilcox: "The XArray provides an improved interface to the radix tree data structure, providing locking as part of the API, specifying GFP flags at allocation time, eliminating preloading, less re-walking the tree, more efficient iterations and not exposing RCU-protected pointers to its users. This patch set 1. Introduces the XArray implementation 2. Converts the pagecache to use it 3. Converts memremap to use it The page cache is the most complex and important user of the radix tree, so converting it was most important. Converting the memremap code removes the only other user of the multiorder code, which allows us to remove the radix tree code that supported it. I have 40+ followup patches to convert many other users of the radix tree over to the XArray, but I'd like to get this part in first. The other conversions haven't been in linux-next and aren't suitable for applying yet, but you can see them in the xarray-conv branch if you're interested" * 'xarray' of git://git.infradead.org/users/willy/linux-dax: (90 commits) radix tree: Remove multiorder support radix tree test: Convert multiorder tests to XArray radix tree tests: Convert item_delete_rcu to XArray radix tree tests: Convert item_kill_tree to XArray radix tree tests: Move item_insert_order radix tree test suite: Remove multiorder benchmarking radix tree test suite: Remove __item_insert memremap: Convert to XArray xarray: Add range store functionality xarray: Move multiorder_check to in-kernel tests xarray: Move multiorder_shrink to kernel tests xarray: Move multiorder account test in-kernel radix tree test suite: Convert iteration test to XArray radix tree test suite: Convert tag_tagged_items to XArray radix tree: Remove radix_tree_clear_tags radix tree: Remove radix_tree_maybe_preload_order radix tree: Remove split/join code radix tree: Remove radix_tree_update_node_t page cache: Finish XArray conversion dax: Convert page fault handlers to XArray ... |
|
|
Andrea Arcangeli
|
7eef5f97c1 |
mm: thp: relocate flush_cache_range() in migrate_misplaced_transhuge_page()
There should be no cache left by the time we overwrite the old transhuge pmd with the new one. It's already too late to flush through the virtual address because we already copied the page data to the new physical address. So flush the cache before the data copy. Also delete the "end" variable to shutoff a "unused variable" warning on x86 where flush_cache_range() is a noop. Link: http://lkml.kernel.org/r/20181015202311.7209-1-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Jerome Glisse <jglisse@redhat.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> |
|
|
Andrea Arcangeli
|
7066f0f933 |
mm: thp: fix mmu_notifier in migrate_misplaced_transhuge_page()
change_huge_pmd() after arming the numa/protnone pmd doesn't flush the TLB
right away. do_huge_pmd_numa_page() flushes the TLB before calling
migrate_misplaced_transhuge_page(). By the time do_huge_pmd_numa_page()
runs some CPU could still access the page through the TLB.
change_huge_pmd() before arming the numa/protnone transhuge pmd calls
mmu_notifier_invalidate_range_start(). So there's no need of
mmu_notifier_invalidate_range_start()/mmu_notifier_invalidate_range_only_end()
sequence in migrate_misplaced_transhuge_page() too, because by the time
migrate_misplaced_transhuge_page() runs, the pmd mapping has already been
invalidated in the secondary MMUs. It has to or if a secondary MMU can
still write to the page, the migrate_page_copy() would lose data.
However an explicit mmu_notifier_invalidate_range() is needed before
migrate_misplaced_transhuge_page() starts copying the data of the
transhuge page or the below can happen for MMU notifier users sharing the
primary MMU pagetables and only implementing ->invalidate_range:
CPU0 CPU1 GPU sharing linux pagetables using
only ->invalidate_range
----------- ------------ ---------
GPU secondary MMU writes to the page
mapped by the transhuge pmd
change_pmd_range()
mmu..._range_start()
->invalidate_range_start() noop
change_huge_pmd()
set_pmd_at(numa/protnone)
pmd_unlock()
do_huge_pmd_numa_page()
CPU TLB flush globally (1)
CPU cannot write to page
migrate_misplaced_transhuge_page()
GPU writes to the page...
migrate_page_copy()
...GPU stops writing to the page
CPU TLB flush (2)
mmu..._range_end() (3)
->invalidate_range_stop() noop
->invalidate_range()
GPU secondary MMU is invalidated
and cannot write to the page anymore
(too late)
Just like we need a CPU TLB flush (1) because the TLB flush (2) arrives
too late, we also need a mmu_notifier_invalidate_range() before calling
migrate_misplaced_transhuge_page(), because the ->invalidate_range() in
(3) also arrives too late.
This requirement is the result of the lazy optimization in
change_huge_pmd() that releases the pmd_lock without first flushing the
TLB and without first calling mmu_notifier_invalidate_range().
Even converting the removed mmu_notifier_invalidate_range_only_end() into
a mmu_notifier_invalidate_range_end() would not have been enough to fix
this, because it run after migrate_page_copy().
After the hugepage data copy is done migrate_misplaced_transhuge_page()
can proceed and call set_pmd_at without having to flush the TLB nor any
secondary MMUs because the secondary MMU invalidate, just like the CPU TLB
flush, has to happen before the migrate_page_copy() is called or it would
be a bug in the first place (and it was for drivers using
->invalidate_range()).
KVM is unaffected because it doesn't implement ->invalidate_range().
The standard PAGE_SIZEd migrate_misplaced_page is less accelerated and
uses the generic migrate_pages which transitions the pte from
numa/protnone to a migration entry in try_to_unmap_one() and flushes TLBs
and all mmu notifiers there before copying the page.
Link: http://lkml.kernel.org/r/20181013002430.698-3-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Andrea Arcangeli
|
d7c3393413 |
mm: thp: fix MADV_DONTNEED vs migrate_misplaced_transhuge_page race condition
Patch series "migrate_misplaced_transhuge_page race conditions". Aaron found a new instance of the THP MADV_DONTNEED race against pmdp_clear_flush* variants, that was apparently left unfixed. While looking into the race found by Aaron, I may have found two more issues in migrate_misplaced_transhuge_page. These race conditions would not cause kernel instability, but they'd corrupt userland data or leave data non zero after MADV_DONTNEED. I did only minor testing, and I don't expect to be able to reproduce this (especially the lack of ->invalidate_range before migrate_page_copy, requires the latest iommu hardware or infiniband to reproduce). The last patch is noop for x86 and it needs further review from maintainers of archs that implement flush_cache_range() (not in CC yet). To avoid confusion, it's not the first patch that introduces the bug fixed in the second patch, even before removing the pmdp_huge_clear_flush_notify, that _notify suffix was called after migrate_page_copy already run. This patch (of 3): This is a corollary of |
|
|
Johannes Weiner
|
1899ad18c6 |
mm: workingset: tell cache transitions from workingset thrashing
Refaults happen during transitions between workingsets as well as in-place thrashing. Knowing the difference between the two has a range of applications, including measuring the impact of memory shortage on the system performance, as well as the ability to smarter balance pressure between the filesystem cache and the swap-backed workingset. During workingset transitions, inactive cache refaults and pushes out established active cache. When that active cache isn't stale, however, and also ends up refaulting, that's bonafide thrashing. Introduce a new page flag that tells on eviction whether the page has been active or not in its lifetime. This bit is then stored in the shadow entry, to classify refaults as transitioning or thrashing. How many page->flags does this leave us with on 32-bit? 20 bits are always page flags 21 if you have an MMU 23 with the zone bits for DMA, Normal, HighMem, Movable 29 with the sparsemem section bits 30 if PAE is enabled 31 with this patch. So on 32-bit PAE, that leaves 1 bit for distinguishing two NUMA nodes. If that's not enough, the system can switch to discontigmem and re-gain the 6 or 7 sparsemem section bits. Link: http://lkml.kernel.org/r/20180828172258.3185-3-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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Matthew Wilcox
|
89eb946a74 |
mm: Convert page migration to XArray
Signed-off-by: Matthew Wilcox <willy@infradead.org> |
|
|
Greg Kroah-Hartman
|
091a1eaa0e |
Merge branch 'akpm'
* akpm: mm: madvise(MADV_DODUMP): allow hugetlbfs pages ocfs2: fix locking for res->tracking and dlm->tracking_list mm/vmscan.c: fix int overflow in callers of do_shrink_slab() mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly mm/vmstat.c: fix outdated vmstat_text proc: restrict kernel stack dumps to root mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes mm/migrate.c: split only transparent huge pages when allocation fails ipc/shm.c: use ERR_CAST() for shm_lock() error return mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl mm, thp: fix mlocking THP page with migration enabled ocfs2: fix crash in ocfs2_duplicate_clusters_by_page() hugetlb: take PMD sharing into account when flushing tlb/caches mm: migration: fix migration of huge PMD shared pages |
|
|
Anshuman Khandual
|
e6112fc300 |
mm/migrate.c: split only transparent huge pages when allocation fails
split_huge_page_to_list() fails on HugeTLB pages. I was experimenting
with moving 32MB contig HugeTLB pages on arm64 (with a debug patch
applied) and hit the following stack trace when the kernel crashed.
[ 3732.462797] Call trace:
[ 3732.462835] split_huge_page_to_list+0x3b0/0x858
[ 3732.462913] migrate_pages+0x728/0xc20
[ 3732.462999] soft_offline_page+0x448/0x8b0
[ 3732.463097] __arm64_sys_madvise+0x724/0x850
[ 3732.463197] el0_svc_handler+0x74/0x110
[ 3732.463297] el0_svc+0x8/0xc
[ 3732.463347] Code: d1000400 f90b0e60 f2fbd5a2 a94982a1 (f9000420)
When unmap_and_move[_huge_page]() fails due to lack of memory, the
splitting should happen only for transparent huge pages not for HugeTLB
pages. PageTransHuge() returns true for both THP and HugeTLB pages.
Hence the conditonal check should test PagesHuge() flag to make sure that
given pages is not a HugeTLB one.
Link: http://lkml.kernel.org/r/1537798495-4996-1-git-send-email-anshuman.khandual@arm.com
Fixes:
|
|
|
Kirill A. Shutemov
|
e125fe405a |
mm, thp: fix mlocking THP page with migration enabled
A transparent huge page is represented by a single entry on an LRU list.
Therefore, we can only make unevictable an entire compound page, not
individual subpages.
If a user tries to mlock() part of a huge page, we want the rest of the
page to be reclaimable.
We handle this by keeping PTE-mapped huge pages on normal LRU lists: the
PMD on border of VM_LOCKED VMA will be split into PTE table.
Introduction of THP migration breaks[1] the rules around mlocking THP
pages. If we had a single PMD mapping of the page in mlocked VMA, the
page will get mlocked, regardless of PTE mappings of the page.
For tmpfs/shmem it's easy to fix by checking PageDoubleMap() in
remove_migration_pmd().
Anon THP pages can only be shared between processes via fork(). Mlocked
page can only be shared if parent mlocked it before forking, otherwise CoW
will be triggered on mlock().
For Anon-THP, we can fix the issue by munlocking the page on removing PTE
migration entry for the page. PTEs for the page will always come after
mlocked PMD: rmap walks VMAs from oldest to newest.
Test-case:
#include <unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <linux/mempolicy.h>
#include <numaif.h>
int main(void)
{
unsigned long nodemask = 4;
void *addr;
addr = mmap((void *)0x20000000UL, 2UL << 20, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKED, -1, 0);
if (fork()) {
wait(NULL);
return 0;
}
mlock(addr, 4UL << 10);
mbind(addr, 2UL << 20, MPOL_PREFERRED | MPOL_F_RELATIVE_NODES,
&nodemask, 4, MPOL_MF_MOVE);
return 0;
}
[1] https://lkml.kernel.org/r/CAOMGZ=G52R-30rZvhGxEbkTw7rLLwBGadVYeo--iizcD3upL3A@mail.gmail.com
Link: http://lkml.kernel.org/r/20180917133816.43995-1-kirill.shutemov@linux.intel.com
Fixes:
|
|
|
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>
|
|
|
Srikar Dronamraju
|
7534612123 |
mm/migrate: Use spin_trylock() while resetting rate limit
Since this spinlock will only serialize the migrate rate limiting, convert the spin_lock() to a spin_trylock(). If another thread is updating, this task can move on. Specjbb2005 results (8 warehouses) Higher bops are better 2 Socket - 2 Node Haswell - X86 JVMS Prev Current %Change 4 205332 198512 -3.32145 1 319785 313559 -1.94693 2 Socket - 4 Node Power8 - PowerNV JVMS Prev Current %Change 8 74912 74761.9 -0.200368 1 206585 214874 4.01239 2 Socket - 2 Node Power9 - PowerNV JVMS Prev Current %Change 4 189162 180536 -4.56011 1 213760 210281 -1.62753 4 Socket - 4 Node Power7 - PowerVM JVMS Prev Current %Change 8 58736.8 56511.4 -3.78877 1 105419 104899 -0.49327 Avoiding stretching of window intervals may be the reason for the regression. Also code now uses READ_ONCE/WRITE_ONCE. That may also be hurting performance to some extent. Some events stats before and after applying the patch. perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86 Event Before After cs 14,285,708 13,818,546 migrations 1,180,621 1,149,960 faults 339,114 385,583 cache-misses 55,205,631,894 55,259,546,768 sched:sched_move_numa 843 2,257 sched:sched_stick_numa 6 9 sched:sched_swap_numa 219 512 migrate:mm_migrate_pages 365 2,225 vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86 Event Before After numa_hint_faults 26907 72692 numa_hint_faults_local 24279 62270 numa_hit 239771 238762 numa_huge_pte_updates 0 48 numa_interleave 68 75 numa_local 239688 238676 numa_other 83 86 numa_pages_migrated 363 2225 numa_pte_updates 27415 98557 perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86 Event Before After cs 3,202,779 3,173,490 migrations 37,186 36,966 faults 106,076 108,776 cache-misses 12,024,873,744 12,200,075,320 sched:sched_move_numa 931 1,264 sched:sched_stick_numa 0 0 sched:sched_swap_numa 1 0 migrate:mm_migrate_pages 637 899 vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86 Event Before After numa_hint_faults 17409 21109 numa_hint_faults_local 14367 17120 numa_hit 73953 72934 numa_huge_pte_updates 20 42 numa_interleave 25 33 numa_local 73892 72866 numa_other 61 68 numa_pages_migrated 668 915 numa_pte_updates 27276 42326 perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV Event Before After cs 8,474,013 8,312,022 migrations 254,934 231,705 faults 320,506 310,242 cache-misses 110,580,458 402,324,573 sched:sched_move_numa 725 193 sched:sched_stick_numa 0 0 sched:sched_swap_numa 7 3 migrate:mm_migrate_pages 145 93 vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV Event Before After numa_hint_faults 22797 11838 numa_hint_faults_local 21539 11216 numa_hit 89308 90689 numa_huge_pte_updates 0 0 numa_interleave 865 1579 numa_local 88955 89634 numa_other 353 1055 numa_pages_migrated 149 92 numa_pte_updates 22930 12109 perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV Event Before After cs 2,195,628 2,170,481 migrations 11,179 10,126 faults 149,656 160,962 cache-misses 8,117,515 10,834,845 sched:sched_move_numa 49 10 sched:sched_stick_numa 0 0 sched:sched_swap_numa 0 0 migrate:mm_migrate_pages 5 2 vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV Event Before After numa_hint_faults 3577 403 numa_hint_faults_local 3476 358 numa_hit 26142 25898 numa_huge_pte_updates 0 0 numa_interleave 358 207 numa_local 26042 25860 numa_other 100 38 numa_pages_migrated 5 2 numa_pte_updates 3587 400 perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM Event Before After cs 100,602,296 110,339,633 migrations 4,135,630 4,139,812 faults 789,256 863,622 cache-misses 226,160,621,058 231,838,045,660 sched:sched_move_numa 1,366 2,196 sched:sched_stick_numa 16 33 sched:sched_swap_numa 374 544 migrate:mm_migrate_pages 1,350 2,469 vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM Event Before After numa_hint_faults 47857 85748 numa_hint_faults_local 39768 66831 numa_hit 240165 242213 numa_huge_pte_updates 0 0 numa_interleave 0 0 numa_local 240165 242211 numa_other 0 2 numa_pages_migrated 1224 2376 numa_pte_updates 48354 86233 perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM Event Before After cs 58,515,496 59,331,057 migrations 564,845 552,019 faults 245,807 266,586 cache-misses 73,603,757,976 73,796,312,990 sched:sched_move_numa 996 981 sched:sched_stick_numa 10 54 sched:sched_swap_numa 193 286 migrate:mm_migrate_pages 646 713 vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM Event Before After numa_hint_faults 13422 14807 numa_hint_faults_local 5619 5738 numa_hit 36118 36230 numa_huge_pte_updates 0 0 numa_interleave 0 0 numa_local 36116 36228 numa_other 2 2 numa_pages_migrated 616 703 numa_pte_updates 13374 14742 Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jirka Hladky <jhladky@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Galbraith <efault@gmx.de> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1537552141-27815-6-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
|
|
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> |
|
|
Naoya Horiguchi
|
6bc9b56433 |
mm: fix race on soft-offlining free huge pages
Patch series "mm: soft-offline: fix race against page allocation".
Xishi recently reported the issue about race on reusing the target pages
of soft offlining. Discussion and analysis showed that we need make
sure that setting PG_hwpoison should be done in the right place under
zone->lock for soft offline. 1/2 handles free hugepage's case, and 2/2
hanldes free buddy page's case.
This patch (of 2):
There's a race condition between soft offline and hugetlb_fault which
causes unexpected process killing and/or hugetlb allocation failure.
The process killing is caused by the following flow:
CPU 0 CPU 1 CPU 2
soft offline
get_any_page
// find the hugetlb is free
mmap a hugetlb file
page fault
...
hugetlb_fault
hugetlb_no_page
alloc_huge_page
// succeed
soft_offline_free_page
// set hwpoison flag
mmap the hugetlb file
page fault
...
hugetlb_fault
hugetlb_no_page
find_lock_page
return VM_FAULT_HWPOISON
mm_fault_error
do_sigbus
// kill the process
The hugetlb allocation failure comes from the following flow:
CPU 0 CPU 1
mmap a hugetlb file
// reserve all free page but don't fault-in
soft offline
get_any_page
// find the hugetlb is free
soft_offline_free_page
// set hwpoison flag
dissolve_free_huge_page
// fail because all free hugepages are reserved
page fault
...
hugetlb_fault
hugetlb_no_page
alloc_huge_page
...
dequeue_huge_page_node_exact
// ignore hwpoisoned hugepage
// and finally fail due to no-mem
The root cause of this is that current soft-offline code is written based
on an assumption that PageHWPoison flag should be set at first to avoid
accessing the corrupted data. This makes sense for memory_failure() or
hard offline, but does not for soft offline because soft offline is about
corrected (not uncorrected) error and is safe from data lost. This patch
changes soft offline semantics where it sets PageHWPoison flag only after
containment of the error page completes successfully.
Link: http://lkml.kernel.org/r/1531452366-11661-2-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>
Suggested-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>
|
|
|
Nick Desaulniers
|
815f0ddb34 |
include/linux/compiler*.h: make compiler-*.h mutually exclusive
Commit |
|
|
Dave Jiang
|
e1fb4a0864 |
dax: remove VM_MIXEDMAP for fsdax and device dax
This patch is reworked from an earlier patch that Dan has posted: https://patchwork.kernel.org/patch/10131727/ VM_MIXEDMAP is used by dax to direct mm paths like vm_normal_page() that the memory page it is dealing with is not typical memory from the linear map. The get_user_pages_fast() path, since it does not resolve the vma, is already using {pte,pmd}_devmap() as a stand-in for VM_MIXEDMAP, so we use that as a VM_MIXEDMAP replacement in some locations. In the cases where there is no pte to consult we fallback to using vma_is_dax() to detect the VM_MIXEDMAP special case. Now that we have explicit driver pfn_t-flag opt-in/opt-out for get_user_pages() support for DAX we can stop setting VM_MIXEDMAP. This also means we no longer need to worry about safely manipulating vm_flags in a future where we support dynamically changing the dax mode of a file. DAX should also now be supported with madvise_behavior(), vma_merge(), and copy_page_range(). This patch has been tested against ndctl unit test. It has also been tested against xfstests commit: 625515d using fake pmem created by memmap and no additional issues have been observed. Link: http://lkml.kernel.org/r/152847720311.55924.16999195879201817653.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Naoya Horiguchi
|
013567be19 |
mm: migrate: fix double call of radix_tree_replace_slot()
radix_tree_replace_slot() is called twice for head page, it's obviously
a bug. Let's fix it.
Link: http://lkml.kernel.org/r/20180423072101.GA12157@hori1.linux.bs1.fc.nec.co.jp
Fixes:
|
|
|
Naoya Horiguchi
|
e71769ae52 |
mm: enable thp migration for shmem thp
My testing for the latest kernel supporting thp migration showed an
infinite loop in offlining the memory block that is filled with shmem
thps. We can get out of the loop with a signal, but kernel should return
with failure in this case.
What happens in the loop is that scan_movable_pages() repeats returning
the same pfn without any progress. That's because page migration always
fails for shmem thps.
In memory offline code, memory blocks containing unmovable pages should be
prevented from being offline targets by has_unmovable_pages() inside
start_isolate_page_range(). So it's possible to change migratability for
non-anonymous thps to avoid the issue, but it introduces more complex and
thp-specific handling in migration code, so it might not good.
So this patch is suggesting to fix the issue by enabling thp migration for
shmem thp. Both of anon/shmem thp are migratable so we don't need
precheck about the type of thps.
Link: http://lkml.kernel.org/r/20180406030706.GA2434@hori1.linux.bs1.fc.nec.co.jp
Fixes: commit
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Michal Hocko
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8f175cf5c9 |
mm: fix do_pages_move status handling
Li Wang has reported that LTP move_pages04 test fails with the current
tree:
LTP move_pages04:
TFAIL : move_pages04.c:143: status[1] is EPERM, expected EFAULT
The test allocates an array of two pages, one is present while the other
is not (resp. backed by zero page) and it expects EFAULT for the second
page as the man page suggests. We are reporting EPERM which doesn't make
any sense and this is a result of a bug from cf5f16b23ec9 ("mm: unclutter
THP migration").
do_pages_move tries to handle as many pages in one batch as possible so we
queue all pages with the same node target together and that corresponds to
[start, i] range which is then used to update status array.
add_page_for_migration will correctly notice the zero (resp. !present)
page and returns with EFAULT which gets written to the status. But if
this is the last page in the array we do not update start and so the last
store_status after the loop will overwrite the range of the last batch
with NUMA_NO_NODE (which corresponds to EPERM).
Fix this by simply bailing out from the last flush if the pagelist is
empty as there is clearly nothing more to do.
Link: http://lkml.kernel.org/r/20180418121255.334-1-mhocko@kernel.org
Fixes: cf5f16b23ec9 ("mm: unclutter THP migration")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Li Wang <liwang@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox
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b93b016313 |
page cache: use xa_lock
Remove the address_space ->tree_lock and use the xa_lock newly added to the radix_tree_root. Rename the address_space ->page_tree to ->i_pages, since we don't really care that it's a tree. [willy@infradead.org: fix nds32, fs/dax.c] Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Jeff Layton <jlayton@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> 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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Michal Hocko
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94723aafb9 |
mm: unclutter THP migration
THP migration is hacked into the generic migration with rather surprising semantic. The migration allocation callback is supposed to check whether the THP can be migrated at once and if that is not the case then it allocates a simple page to migrate. unmap_and_move then fixes that up by spliting the THP into small pages while moving the head page to the newly allocated order-0 page. Remaning pages are moved to the LRU list by split_huge_page. The same happens if the THP allocation fails. This is really ugly and error prone [1]. I also believe that split_huge_page to the LRU lists is inherently wrong because all tail pages are not migrated. Some callers will just work around that by retrying (e.g. memory hotplug). There are other pfn walkers which are simply broken though. e.g. madvise_inject_error will migrate head and then advances next pfn by the huge page size. do_move_page_to_node_array, queue_pages_range (migrate_pages, mbind), will simply split the THP before migration if the THP migration is not supported then falls back to single page migration but it doesn't handle tail pages if the THP migration path is not able to allocate a fresh THP so we end up with ENOMEM and fail the whole migration which is a questionable behavior. Page compaction doesn't try to migrate large pages so it should be immune. This patch tries to unclutter the situation by moving the special THP handling up to the migrate_pages layer where it actually belongs. We simply split the THP page into the existing list if unmap_and_move fails with ENOMEM and retry. So we will _always_ migrate all THP subpages and specific migrate_pages users do not have to deal with this case in a special way. [1] http://lkml.kernel.org/r/20171121021855.50525-1-zi.yan@sent.com Link: http://lkml.kernel.org/r/20180103082555.14592-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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
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666feb21a0 |
mm, migrate: remove reason argument from new_page_t
No allocation callback is using this argument anymore. new_page_node used to use this parameter to convey node_id resp. migration error up to move_pages code (do_move_page_to_node_array). The error status never made it into the final status field and we have a better way to communicate node id to the status field now. All other allocation callbacks simply ignored the argument so we can drop it finally. [mhocko@suse.com: fix migration callback] Link: http://lkml.kernel.org/r/20180105085259.GH2801@dhcp22.suse.cz [akpm@linux-foundation.org: fix alloc_misplaced_dst_page()] [mhocko@kernel.org: fix build] Link: http://lkml.kernel.org/r/20180103091134.GB11319@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20180103082555.14592-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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
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a49bd4d716 |
mm, numa: rework do_pages_move
Patch series "unclutter thp migration" Motivation: THP migration is hacked into the generic migration with rather surprising semantic. The migration allocation callback is supposed to check whether the THP can be migrated at once and if that is not the case then it allocates a simple page to migrate. unmap_and_move then fixes that up by splitting the THP into small pages while moving the head page to the newly allocated order-0 page. Remaining pages are moved to the LRU list by split_huge_page. The same happens if the THP allocation fails. This is really ugly and error prone [2]. I also believe that split_huge_page to the LRU lists is inherently wrong because all tail pages are not migrated. Some callers will just work around that by retrying (e.g. memory hotplug). There are other pfn walkers which are simply broken though. e.g. madvise_inject_error will migrate head and then advances next pfn by the huge page size. do_move_page_to_node_array, queue_pages_range (migrate_pages, mbind), will simply split the THP before migration if the THP migration is not supported then falls back to single page migration but it doesn't handle tail pages if the THP migration path is not able to allocate a fresh THP so we end up with ENOMEM and fail the whole migration which is a questionable behavior. Page compaction doesn't try to migrate large pages so it should be immune. The first patch reworks do_pages_move which relies on a very ugly calling semantic when the return status is pushed to the migration path via private pointer. It uses pre allocated fixed size batching to achieve that. We simply cannot do the same if a THP is to be split during the migration path which is done in the patch 3. Patch 2 is follow up cleanup which removes the mentioned return status calling convention ugliness. On a side note: There are some semantic issues I have encountered on the way when working on patch 1 but I am not addressing them here. E.g. trying to move THP tail pages will result in either success or EBUSY (the later one more likely once we isolate head from the LRU list). Hugetlb reports EACCESS on tail pages. Some errors are reported via status parameter but migration failures are not even though the original `reason' argument suggests there was an intention to do so. From a quick look into git history this never worked. I have tried to keep the semantic unchanged. Then there is a relatively minor thing that the page isolation might fail because of pages not being on the LRU - e.g. because they are sitting on the per-cpu LRU caches. Easily fixable. This patch (of 3): do_pages_move is supposed to move user defined memory (an array of addresses) to the user defined numa nodes (an array of nodes one for each address). The user provided status array then contains resulting numa node for each address or an error. The semantic of this function is little bit confusing because only some errors are reported back. Notably migrate_pages error is only reported via the return value. This patch doesn't try to address these semantic nuances but rather change the underlying implementation. Currently we are processing user input (which can be really large) in batches which are stored to a temporarily allocated page. Each address is resolved to its struct page and stored to page_to_node structure along with the requested target numa node. The array of these structures is then conveyed down the page migration path via private argument. new_page_node then finds the corresponding structure and allocates the proper target page. What is the problem with the current implementation and why to change it? Apart from being quite ugly it also doesn't cope with unexpected pages showing up on the migration list inside migrate_pages path. That doesn't happen currently but the follow up patch would like to make the thp migration code more clear and that would need to split a THP into the list for some cases. How does the new implementation work? Well, instead of batching into a fixed size array we simply batch all pages that should be migrated to the same node and isolate all of them into a linked list which doesn't require any additional storage. This should work reasonably well because page migration usually migrates larger ranges of memory to a specific node. So the common case should work equally well as the current implementation. Even if somebody constructs an input where the target numa nodes would be interleaved we shouldn't see a large performance impact because page migration alone doesn't really benefit from batching. mmap_sem batching for the lookup is quite questionable and isolate_lru_page which would benefit from batching is not using it even in the current implementation. Link: http://lkml.kernel.org/r/20180103082555.14592-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.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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Ralph Campbell
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07707125ae |
mm/migrate: properly preserve write attribute in special migrate entry
Use of pte_write(pte) is only valid for present pte, the common code which set the migration entry can be reach for both valid present pte and special swap entry (for device memory). Fix the code to use the mpfn value which properly handle both cases. On x86 this did not have any bad side effect because pte write bit is below PAGE_BIT_GLOBAL and thus special swap entry have it set to 0 which in turn means we were always creating read only special migration entry. So once migration did finish we always write protected the CPU page table entry (moreover this is only an issue when migrating from device memory to system memory). End effect is that CPU write access would fault again and restore write permission. This behaviour isn't too bad; it just burns CPU cycles by forcing CPU to take a second fault on write access. ie, double faulting the same address. There is no corruption or incorrect states (it behaves as a COWed page from a fork with a mapcount of 1). Link: http://lkml.kernel.org/r/20180402023506.12180-1-jglisse@redhat.com Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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09a913a7a9 |
sched/numa: avoid trapping faults and attempting migration of file-backed dirty pages
change_pte_range is called from task work context to mark PTEs for
receiving NUMA faulting hints. If the marked pages are dirty then
migration may fail. Some filesystems cannot migrate dirty pages without
blocking so are skipped in MIGRATE_ASYNC mode which just wastes CPU.
Even when they can, it can be a waste of cycles when the pages are
shared forcing higher scan rates. This patch avoids marking shared
dirty pages for hinting faults but also will skip a migration if the
page was dirtied after the scanner updated a clean page.
This is most noticeable running the NASA Parallel Benchmark when backed
by btrfs, the default root filesystem for some distributions, but also
noticeable when using XFS.
The following are results from a 4-socket machine running a 4.16-rc4
kernel with some scheduler patches that are pending for the next merge
window.
4.16.0-rc4 4.16.0-rc4
schedtip-20180309 nodirty-v1
Time cg.D 459.07 ( 0.00%) 444.21 ( 3.24%)
Time ep.D 76.96 ( 0.00%) 77.69 ( -0.95%)
Time is.D 25.55 ( 0.00%) 27.85 ( -9.00%)
Time lu.D 601.58 ( 0.00%) 596.87 ( 0.78%)
Time mg.D 107.73 ( 0.00%) 108.22 ( -0.45%)
is.D regresses slightly in terms of absolute time but note that that
particular load varies quite a bit from run to run. The more relevant
observation is the total system CPU usage.
4.16.0-rc4 4.16.0-rc4
schedtip-20180309 nodirty-v1
User 71471.91 70627.04
System 11078.96 8256.13
Elapsed 661.66 632.74
That is a substantial drop in system CPU usage and overall the workload
completes faster. The NUMA balancing statistics are also interesting
NUMA base PTE updates 111407972 139848884
NUMA huge PMD updates 206506 264869
NUMA page range updates 217139044 275461812
NUMA hint faults 4300924 3719784
NUMA hint local faults 3012539 3416618
NUMA hint local percent 70 91
NUMA pages migrated 1517487 1358420
While more PTEs are scanned due to changes in what faults are gathered,
it's clear that a far higher percentage of faults are local as the bulk
of the remote hits were dirty pages that, in this case with btrfs, had
no chance of migrating.
The following is a comparison when using XFS as that is a more realistic
filesystem choice for a data partition
4.16.0-rc4 4.16.0-rc4
schedtip-20180309 nodirty-v1r47
Time cg.D 485.28 ( 0.00%) 442.62 ( 8.79%)
Time ep.D 77.68 ( 0.00%) 77.54 ( 0.18%)
Time is.D 26.44 ( 0.00%) 24.79 ( 6.24%)
Time lu.D 597.46 ( 0.00%) 597.11 ( 0.06%)
Time mg.D 142.65 ( 0.00%) 105.83 ( 25.81%)
That is a reasonable gain on two relatively long-lived workloads. While
not presented, there is also a substantial drop in system CPu usage and
the NUMA balancing stats show similar improvements in locality as btrfs
did.
Link: http://lkml.kernel.org/r/20180326094334.zserdec62gwmmfqf@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dominik Brodowski
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7addf44388 |
mm: add kernel_move_pages() helper, move compat syscall to mm/migrate.c
Move compat_sys_move_pages() to mm/migrate.c and make it call a newly introduced helper -- kernel_move_pages() -- instead of the syscall. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> |
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Michal Hocko
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ab5ac90aec |
mm, hugetlb: do not rely on overcommit limit during migration
hugepage migration relies on __alloc_buddy_huge_page to get a new page. This has 2 main disadvantages. 1) it doesn't allow to migrate any huge page if the pool is used completely which is not an exceptional case as the pool is static and unused memory is just wasted. 2) it leads to a weird semantic when migration between two numa nodes might increase the pool size of the destination NUMA node while the page is in use. The issue is caused by per NUMA node surplus pages tracking (see free_huge_page). Address both issues by changing the way how we allocate and account pages allocated for migration. Those should temporal by definition. So we mark them that way (we will abuse page flags in the 3rd page) and update free_huge_page to free such pages to the page allocator. Page migration path then just transfers the temporal status from the new page to the old one which will be freed on the last reference. The global surplus count will never change during this path but we still have to be careful when migrating a per-node suprlus page. This is now handled in move_hugetlb_state which is called from the migration path and it copies the hugetlb specific page state and fixes up the accounting when needed Rename __alloc_buddy_huge_page to __alloc_surplus_huge_page to better reflect its purpose. The new allocation routine for the migration path is __alloc_migrate_huge_page. The user visible effect of this patch is that migrated pages are really temporal and they travel between NUMA nodes as per the migration request: Before migration /sys/devices/system/node/node0/hugepages/hugepages-2048kB/free_hugepages:0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:1 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/surplus_hugepages:0 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/free_hugepages:0 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/surplus_hugepages:0 After /sys/devices/system/node/node0/hugepages/hugepages-2048kB/free_hugepages:0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/surplus_hugepages:0 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/free_hugepages:0 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:1 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/surplus_hugepages:0 with the previous implementation, both nodes would have nr_hugepages:1 until the page is freed. Link: http://lkml.kernel.org/r/20180103093213.26329-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds
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f55e1014f9 |
Revert "mm, thp: Do not make pmd/pud dirty without a reason"
This reverts commit
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Kirill A. Shutemov
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152e93af3c |
mm, thp: Do not make pmd/pud dirty without a reason
Currently we make page table entries dirty all the time regardless of access type and don't even consider if the mapping is write-protected. The reasoning is that we don't really need dirty tracking on THP and making the entry dirty upfront may save some time on first write to the page. Unfortunately, such approach may result in false-positive can_follow_write_pmd() for huge zero page or read-only shmem file. Let's only make page dirty only if we about to write to the page anyway (as we do for small pages). I've restructured the code to make entry dirty inside maybe_p[mu]d_mkwrite(). It also takes into account if the vma is write-protected. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse
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4645b9fe84 |
mm/mmu_notifier: avoid call to invalidate_range() in range_end()
This is an optimization patch that only affect mmu_notifier users which
rely on the invalidate_range() callback. This patch avoids calling that
callback twice in a row from inside __mmu_notifier_invalidate_range_end
Existing pattern (before this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_end()
mmu_notifier_invalidate_range()
New pattern (after this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_only_end()
We call the invalidate_range callback after clearing the page table
under the page table lock and we skip the call to invalidate_range
inside the __mmu_notifier_invalidate_range_end() function.
Idea from Andrea Arcangeli
Link: http://lkml.kernel.org/r/20171017031003.7481-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Greg Kroah-Hartman
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b24413180f |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Mark Hairgrove
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e20d103b6c |
mm/migrate: fix indexing bug (off by one) and avoid out of bound access
Index was incremented before last use and thus the second array could
dereference to an invalid address (not mentioning the fact that it did
not properly clear the entry we intended to clear).
Link: http://lkml.kernel.org/r/1506973525-16491-1-git-send-email-jglisse@redhat.com
Fixes:
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Jérôme Glisse
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6b368cd4a4 |
mm/hmm: avoid bloating arch that do not make use of HMM
This moves all new code including new page migration helper behind kernel Kconfig option so that there is no codee bloat for arch or user that do not want to use HMM or any of its associated features. arm allyesconfig (without all the patchset, then with and this patch): text data bss dec hex filename 83721896 46511131 27582964 157815991 96814b7 ../without/vmlinux 83722364 46511131 27582964 157816459 968168b vmlinux [jglisse@redhat.com: struct hmm is only use by HMM mirror functionality] Link: http://lkml.kernel.org/r/20170825213133.27286-1-jglisse@redhat.com [sfr@canb.auug.org.au: fix build (arm multi_v7_defconfig)] Link: http://lkml.kernel.org/r/20170828181849.323ab81b@canb.auug.org.au Link: http://lkml.kernel.org/r/20170818032858.7447-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dan Williams <dan.j.williams@intel.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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Jérôme Glisse
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df6ad69838 |
mm/device-public-memory: device memory cache coherent with CPU
Platform with advance system bus (like CAPI or CCIX) allow device memory to be accessible from CPU in a cache coherent fashion. Add a new type of ZONE_DEVICE to represent such memory. The use case are the same as for the un-addressable device memory but without all the corners cases. Link: http://lkml.kernel.org/r/20170817000548.32038-19-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse
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8315ada7f0 |
mm/migrate: allow migrate_vma() to alloc new page on empty entry
This allows callers of migrate_vma() to allocate new page for empty CPU page table entry (pte_none or back by zero page). This is only for anonymous memory and it won't allow new page to be instanced if the userfaultfd is armed. This is useful to device driver that want to migrate a range of virtual address and would rather allocate new memory than having to fault later on. Link: http://lkml.kernel.org/r/20170817000548.32038-18-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse
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a5430dda8a |
mm/migrate: support un-addressable ZONE_DEVICE page in migration
Allow to unmap and restore special swap entry of un-addressable ZONE_DEVICE memory. Link: http://lkml.kernel.org/r/20170817000548.32038-17-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse
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8c3328f1f3 |
mm/migrate: migrate_vma() unmap page from vma while collecting pages
Common case for migration of virtual address range is page are map only once inside the vma in which migration is taking place. Because we already walk the CPU page table for that range we can directly do the unmap there and setup special migration swap entry. Link: http://lkml.kernel.org/r/20170817000548.32038-16-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse
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8763cb45ab |
mm/migrate: new memory migration helper for use with device memory
This patch add a new memory migration helpers, which migrate memory backing a range of virtual address of a process to different memory (which can be allocated through special allocator). It differs from numa migration by working on a range of virtual address and thus by doing migration in chunk that can be large enough to use DMA engine or special copy offloading engine. Expected users are any one with heterogeneous memory where different memory have different characteristics (latency, bandwidth, ...). As an example IBM platform with CAPI bus can make use of this feature to migrate between regular memory and CAPI device memory. New CPU architecture with a pool of high performance memory not manage as cache but presented as regular memory (while being faster and with lower latency than DDR) will also be prime user of this patch. Migration to private device memory will be useful for device that have large pool of such like GPU, NVidia plans to use HMM for that. Link: http://lkml.kernel.org/r/20170817000548.32038-15-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse
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2916ecc0f9 |
mm/migrate: new migrate mode MIGRATE_SYNC_NO_COPY
Introduce a new migration mode that allow to offload the copy to a device
DMA engine. This changes the workflow of migration and not all
address_space migratepage callback can support this.
This is intended to be use by migrate_vma() which itself is use for thing
like HMM (see include/linux/hmm.h).
No additional per-filesystem migratepage testing is needed. I disables
MIGRATE_SYNC_NO_COPY in all problematic migratepage() callback and i
added comment in those to explain why (part of this patch). The commit
message is unclear it should say that any callback that wish to support
this new mode need to be aware of the difference in the migration flow
from other mode.
Some of these callbacks do extra locking while copying (aio, zsmalloc,
balloon, ...) and for DMA to be effective you want to copy multiple
pages in one DMA operations. But in the problematic case you can not
easily hold the extra lock accross multiple call to this callback.
Usual flow is:
For each page {
1 - lock page
2 - call migratepage() callback
3 - (extra locking in some migratepage() callback)
4 - migrate page state (freeze refcount, update page cache, buffer
head, ...)
5 - copy page
6 - (unlock any extra lock of migratepage() callback)
7 - return from migratepage() callback
8 - unlock page
}
The new mode MIGRATE_SYNC_NO_COPY:
1 - lock multiple pages
For each page {
2 - call migratepage() callback
3 - abort in all problematic migratepage() callback
4 - migrate page state (freeze refcount, update page cache, buffer
head, ...)
} // finished all calls to migratepage() callback
5 - DMA copy multiple pages
6 - unlock all the pages
To support MIGRATE_SYNC_NO_COPY in the problematic case we would need a
new callback migratepages() (for instance) that deals with multiple
pages in one transaction.
Because the problematic cases are not important for current usage I did
not wanted to complexify this patchset even more for no good reason.
Link: http://lkml.kernel.org/r/20170817000548.32038-14-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Evgeny Baskakov <ebaskakov@nvidia.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mark Hairgrove <mhairgrove@nvidia.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Sherry Cheung <SCheung@nvidia.com>
Cc: Subhash Gutti <sgutti@nvidia.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Bob Liu <liubo95@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Naoya Horiguchi
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e8db67eb0d |
mm: migrate: move_pages() supports thp migration
This patch enables thp migration for move_pages(2). Link: http://lkml.kernel.org/r/20170717193955.20207-10-zi.yan@sent.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> 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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Zi Yan
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616b837153 |
mm: thp: enable thp migration in generic path
Add thp migration's core code, including conversions between a PMD entry and a swap entry, setting PMD migration entry, removing PMD migration entry, and waiting on PMD migration entries. This patch makes it possible to support thp migration. If you fail to allocate a destination page as a thp, you just split the source thp as we do now, and then enter the normal page migration. If you succeed to allocate destination thp, you enter thp migration. Subsequent patches actually enable thp migration for each caller of page migration by allowing its get_new_page() callback to allocate thps. [zi.yan@cs.rutgers.edu: fix gcc-4.9.0 -Wmissing-braces warning] Link: http://lkml.kernel.org/r/A0ABA698-7486-46C3-B209-E95A9048B22C@cs.rutgers.edu [akpm@linux-foundation.org: fix x86_64 allnoconfig warning] Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> 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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Linus Torvalds
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197e7e5213 |
Sanitize 'move_pages()' permission checks
The 'move_paghes()' system call was introduced long long ago with the same permission checks as for sending a signal (except using CAP_SYS_NICE instead of CAP_SYS_KILL for the overriding capability). That turns out to not be a great choice - while the system call really only moves physical page allocations around (and you need other capabilities to do a lot of it), you can check the return value to map out some the virtual address choices and defeat ASLR of a binary that still shares your uid. So change the access checks to the more common 'ptrace_may_access()' model instead. This tightens the access checks for the uid, and also effectively changes the CAP_SYS_NICE check to CAP_SYS_PTRACE, but it's unlikely that anybody really _uses_ this legacy system call any more (we hav ebetter NUMA placement models these days), so I expect nobody to notice. Famous last words. Reported-by: Otto Ebeling <otto.ebeling@iki.fi> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Nadav Amit
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a9b802500e |
Revert "mm: numa: defer TLB flush for THP migration as long as possible"
While deferring TLB flushes is a good practice, the reverted patch
caused pending TLB flushes to be checked while the page-table lock is
not taken. As a result, in architectures with weak memory model (PPC),
Linux may miss a memory-barrier, miss the fact TLB flushes are pending,
and cause (in theory) a memory corruption.
Since the alternative of using smp_mb__after_unlock_lock() was
considered a bit open-coded, and the performance impact is expected to
be small, the previous patch is reverted.
This reverts
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Will Deacon
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f4e177d126 |
mm/migrate.c: stabilise page count when migrating transparent hugepages
When migrating a transparent hugepage, migrate_misplaced_transhuge_page guards itself against a concurrent fastgup of the page by checking that the page count is equal to 2 before and after installing the new pmd. If the page count changes, then the pmd is reverted back to the original entry, however there is a small window where the new (possibly writable) pmd is installed and the underlying page could be written by userspace. Restoring the old pmd could therefore result in loss of data. This patch fixes the problem by freezing the page count whilst updating the page tables, which protects against a concurrent fastgup without the need to restore the old pmd in the failure case (since the page count can no longer change under our feet). Link: http://lkml.kernel.org/r/1497349722-6731-4-git-send-email-will.deacon@arm.com Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Steve Capper <steve.capper@arm.com> 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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Anshuman Khandual
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c3114a84f7 |
mm: hugetlb: soft-offline: dissolve source hugepage after successful migration
Currently hugepage migrated by soft-offline (i.e. due to correctable memory errors) is contained as a hugepage, which means many non-error pages in it are unreusable, i.e. wasted. This patch solves this issue by dissolving source hugepages into buddy. As done in previous patch, PageHWPoison is set only on a head page of the error hugepage. Then in dissoliving we move the PageHWPoison flag to the raw error page so that all healthy subpages return back to buddy. [arnd@arndb.de: fix warnings: replace some macros with inline functions] Link: http://lkml.kernel.org/r/20170609102544.2947326-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1496305019-5493-5-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: 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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Aneesh Kumar K.V
|
383321ab85 |
mm/hugetlb/migration: use set_huge_pte_at instead of set_pte_at
Patch series "HugeTLB migration support for PPC64", v2. This patch (of 9): The right interface to use to set a hugetlb pte entry is set_huge_pte_at. Use that instead of set_pte_at. Link: http://lkml.kernel.org/r/1494926612-23928-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Minchan Kim
|
e4b8222271 |
mm: make rmap_one boolean function
rmap_one's return value controls whether rmap_work should contine to scan other ptes or not so it's target for changing to boolean. Return true if the scan should be continued. Otherwise, return false to stop the scanning. This patch makes rmap_one's return value to boolean. Link: http://lkml.kernel.org/r/1489555493-14659-10-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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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Shaohua Li
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d44d363f65 |
mm: don't assume anonymous pages have SwapBacked flag
There are a few places the code assumes anonymous pages should have SwapBacked flag set. MADV_FREE pages are anonymous pages but we are going to add them to LRU_INACTIVE_FILE list and clear SwapBacked flag for them. The assumption doesn't hold any more, so fix them. Link: http://lkml.kernel.org/r/3945232c0df3dd6c4ef001976f35a95f18dcb407.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.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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Johannes Weiner
|
15038d0de9 |
mm: remove unnecessary reclaimability check from NUMA balancing target
NUMA balancing already checks the watermarks of the target node to decide whether it's a suitable balancing target. Whether the node is reclaimable or not is irrelevant when we don't intend to reclaim. Link: http://lkml.kernel.org/r/20170228214007.5621-5-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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Rabin Vincent
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fc280fe871 |
mm: prevent NR_ISOLATE_* stats from going negative
Commit |
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Naoya Horiguchi
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4b0ece6fa0 |
mm: migrate: fix remove_migration_pte() for ksm pages
I found that calling page migration for ksm pages causes the following
bug:
page:ffffea0004d51180 count:2 mapcount:2 mapping:ffff88013c785141 index:0x913
flags: 0x57ffffc0040068(uptodate|lru|active|swapbacked)
raw: 0057ffffc0040068 ffff88013c785141 0000000000000913 0000000200000001
raw: ffffea0004d5f9e0 ffffea0004d53f60 0000000000000000 ffff88007d81b800
page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
page->mem_cgroup:ffff88007d81b800
------------[ cut here ]------------
kernel BUG at /src/linux-dev/mm/rmap.c:1086!
invalid opcode: 0000 [#1] SMP
Modules linked in: ppdev parport_pc virtio_balloon i2c_piix4 pcspkr parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi ata_piix 8139too libata virtio_blk 8139cp crc32c_intel mii virtio_pci virtio_ring serio_raw virtio floppy dm_mirror dm_region_hash dm_log dm_mod
CPU: 0 PID: 3162 Comm: bash Not tainted 4.11.0-rc2-mm1+ #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:do_page_add_anon_rmap+0x1ba/0x260
RSP: 0018:ffffc90002473b30 EFLAGS: 00010282
RAX: 0000000000000021 RBX: ffffea0004d51180 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff88007dc0dfe0
RBP: ffffc90002473b58 R08: 00000000fffffffe R09: 00000000000001c1
R10: 0000000000000005 R11: 00000000000001c0 R12: ffff880139ab3d80
R13: 0000000000000000 R14: 0000700000000200 R15: 0000160000000000
FS: 00007f5195f50740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd450287000 CR3: 000000007a08e000 CR4: 00000000001406f0
Call Trace:
page_add_anon_rmap+0x18/0x20
remove_migration_pte+0x220/0x2c0
rmap_walk_ksm+0x143/0x220
rmap_walk+0x55/0x60
remove_migration_ptes+0x53/0x80
migrate_pages+0x8ed/0xb60
soft_offline_page+0x309/0x8d0
store_soft_offline_page+0xaf/0xf0
dev_attr_store+0x18/0x30
sysfs_kf_write+0x3a/0x50
kernfs_fop_write+0xff/0x180
__vfs_write+0x37/0x160
vfs_write+0xb2/0x1b0
SyS_write+0x55/0xc0
do_syscall_64+0x67/0x180
entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7f51956339e0
RSP: 002b:00007ffcfa0dffc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f51956339e0
RDX: 000000000000000c RSI: 00007f5195f53000 RDI: 0000000000000001
RBP: 00007f5195f53000 R08: 000000000000000a R09: 00007f5195f50740
R10: 000000000000000b R11: 0000000000000246 R12: 00007f5195907400
R13: 000000000000000c R14: 0000000000000001 R15: 0000000000000000
Code: fe ff ff 48 81 c2 00 02 00 00 48 89 55 d8 e8 2e c3 fd ff 48 8b 55 d8 e9 42 ff ff ff 48 c7 c6 e0 52 a1 81 48 89 df e8 46 ad fe ff <0f> 0b 48 83 e8 01 e9 7f fe ff ff 48 83 e8 01 e9 96 fe ff ff 48
RIP: do_page_add_anon_rmap+0x1ba/0x260 RSP: ffffc90002473b30
---[ end trace a679d00f4af2df48 ]---
Kernel panic - not syncing: Fatal exception
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception
The problem is in the following lines:
new = page - pvmw.page->index +
linear_page_index(vma, pvmw.address);
The 'new' is calculated with 'page' which is given by the caller as a
destination page and some offset adjustment for thp. But this doesn't
properly work for ksm pages because pvmw.page->index doesn't change for
each address but linear_page_index() changes, which means that 'new'
points to different pages for each addresses backed by the ksm page. As
a result, we try to set totally unrelated pages as destination pages,
and that causes kernel crash.
This patch fixes the miscalculation and makes ksm page migration work
fine.
Fixes:
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Ingo Molnar
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6e84f31522 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h>
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Kirill A. Shutemov
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3fe87967c5 |
mm: convert remove_migration_pte() to use page_vma_mapped_walk()
remove_migration_pte() also can easily be converted to page_vma_mapped_walk(). [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170129173858.45174-13-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.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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Yisheng Xie
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9e5bcd610f |
mm/migration: make isolate_movable_page() return int type
Patch series "HWPOISON: soft offlining for non-lru movable page", v6.
After Minchan's commit
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Nicholas Piggin
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6326fec112 |
mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked
A page is not added to the swap cache without being swap backed, so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Andrew Lutomirski <luto@kernel.org> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Johannes Weiner
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6d75f366b9 |
lib: radix-tree: check accounting of existing slot replacement users
The bug in khugepaged fixed earlier in this series shows that radix tree slot replacement is fragile; and it will become more so when not only NULL<->!NULL transitions need to be caught but transitions from and to exceptional entries as well. We need checks. Re-implement radix_tree_replace_slot() on top of the sanity-checked __radix_tree_replace(). This requires existing callers to also pass the radix tree root, but it'll warn us when somebody replaces slots with contents that need proper accounting (transitions between NULL entries, real entries, exceptional entries) and where a replacement through the slot pointer would corrupt the radix tree node counts. Link: http://lkml.kernel.org/r/20161117193021.GB23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Ming Ling
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6afcf8ef0c |
mm, compaction: fix NR_ISOLATED_* stats for pfn based migration
Since commit |
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Andrea Arcangeli
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6d2329f887 |
mm: vm_page_prot: update with WRITE_ONCE/READ_ONCE
vma->vm_page_prot is read lockless from the rmap_walk, it may be updated concurrently and this prevents the risk of reading intermediate values. Link: http://lkml.kernel.org/r/1474660305-19222-1-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.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
|
2516035499 |
mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations
After the previous patch, we can distinguish costly allocations that
should be really lightweight, such as THP page faults, with
__GFP_NORETRY. This means we don't need to recognize khugepaged
allocations via PF_KTHREAD anymore. We can also change THP page faults
in areas where madvise(MADV_HUGEPAGE) was used to try as hard as
khugepaged, as the process has indicated that it benefits from THP's and
is willing to pay some initial latency costs.
We can also make the flags handling less cryptic by distinguishing
GFP_TRANSHUGE_LIGHT (no reclaim at all, default mode in page fault) from
GFP_TRANSHUGE (only direct reclaim, khugepaged default). Adding
__GFP_NORETRY or __GFP_KSWAPD_RECLAIM is done where needed.
The patch effectively changes the current GFP_TRANSHUGE users as
follows:
* get_huge_zero_page() - the zero page lifetime should be relatively
long and it's shared by multiple users, so it's worth spending some
effort on it. We use GFP_TRANSHUGE, and __GFP_NORETRY is not added.
This also restores direct reclaim to this allocation, which was
unintentionally removed by commit e4a49efe4e7e ("mm: thp: set THP defrag
by default to madvise and add a stall-free defrag option")
* alloc_hugepage_khugepaged_gfpmask() - this is khugepaged, so latency
is not an issue. So if khugepaged "defrag" is enabled (the default), do
reclaim via GFP_TRANSHUGE without __GFP_NORETRY. We can remove the
PF_KTHREAD check from page alloc.
As a side-effect, khugepaged will now no longer check if the initial
compaction was deferred or contended. This is OK, as khugepaged sleep
times between collapsion attempts are long enough to prevent noticeable
disruption, so we should allow it to spend some effort.
* migrate_misplaced_transhuge_page() - already was masking out
__GFP_RECLAIM, so just convert to GFP_TRANSHUGE_LIGHT which is
equivalent.
* alloc_hugepage_direct_gfpmask() - vma's with VM_HUGEPAGE (via madvise)
are now allocating without __GFP_NORETRY. Other vma's keep using
__GFP_NORETRY if direct reclaim/compaction is at all allowed (by default
it's allowed only for madvised vma's). The rest is conversion to
GFP_TRANSHUGE(_LIGHT).
[mhocko@suse.com: suggested GFP_TRANSHUGE_LIGHT]
Link: http://lkml.kernel.org/r/20160721073614.24395-7-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: 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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Mel Gorman
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5a1c84b404 |
mm: remove reclaim and compaction retry approximations
If per-zone LRU accounting is available then there is no point approximating whether reclaim and compaction should retry based on pgdat statistics. This is effectively a revert of "mm, vmstat: remove zone and node double accounting by approximating retries" with the difference that inactive/active stats are still available. This preserves the history of why the approximation was retried and why it had to be reverted to handle OOM kills on 32-bit systems. Link: http://lkml.kernel.org/r/1469110261-7365-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> 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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Mel Gorman
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bca6759258 |
mm, vmstat: remove zone and node double accounting by approximating retries
The number of LRU pages, dirty pages and writeback pages must be
accounted for on both zones and nodes because of the reclaim retry
logic, compaction retry logic and highmem calculations all depending on
per-zone stats.
Many lowmem allocations are immune from OOM kill due to a check in
__alloc_pages_may_oom for (ac->high_zoneidx < ZONE_NORMAL) since commit
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Mel Gorman
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11fb998986 |
mm: move most file-based accounting to the node
There are now a number of accounting oddities such as mapped file pages being accounted for on the node while the total number of file pages are accounted on the zone. This can be coped with to some extent but it's confusing so this patch moves the relevant file-based accounted. Due to throttling logic in the page allocator for reliable OOM detection, it is still necessary to track dirty and writeback pages on a per-zone basis. [mgorman@techsingularity.net: fix NR_ZONE_WRITE_PENDING accounting] Link: http://lkml.kernel.org/r/1468404004-5085-5-git-send-email-mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1467970510-21195-20-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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4b9d0fab71 |
mm: rename NR_ANON_PAGES to NR_ANON_MAPPED
NR_FILE_PAGES is the number of file pages. NR_FILE_MAPPED is the number of mapped file pages. NR_ANON_PAGES is the number of mapped anon pages. This is unhelpful naming as it's easy to confuse NR_FILE_MAPPED and NR_ANON_PAGES for mapped pages. This patch renames NR_ANON_PAGES so we have NR_FILE_PAGES is the number of file pages. NR_FILE_MAPPED is the number of mapped file pages. NR_ANON_MAPPED is the number of mapped anon pages. Link: http://lkml.kernel.org/r/1467970510-21195-19-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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599d0c954f |
mm, vmscan: move LRU lists to node
This moves the LRU lists from the zone to the node and related data such as counters, tracing, congestion tracking and writeback tracking. Unfortunately, due to reclaim and compaction retry logic, it is necessary to account for the number of LRU pages on both zone and node logic. Most reclaim logic is based on the node counters but the retry logic uses the zone counters which do not distinguish inactive and active sizes. It would be possible to leave the LRU counters on a per-zone basis but it's a heavier calculation across multiple cache lines that is much more frequent than the retry checks. Other than the LRU counters, this is mostly a mechanical patch but note that it introduces a number of anomalies. For example, the scans are per-zone but using per-node counters. We also mark a node as congested when a zone is congested. This causes weird problems that are fixed later but is easier to review. In the event that there is excessive overhead on 32-bit systems due to the nodes being on LRU then there are two potential solutions 1. Long-term isolation of highmem pages when reclaim is lowmem When pages are skipped, they are immediately added back onto the LRU list. If lowmem reclaim persisted for long periods of time, the same highmem pages get continually scanned. The idea would be that lowmem keeps those pages on a separate list until a reclaim for highmem pages arrives that splices the highmem pages back onto the LRU. It potentially could be implemented similar to the UNEVICTABLE list. That would reduce the skip rate with the potential corner case is that highmem pages have to be scanned and reclaimed to free lowmem slab pages. 2. Linear scan lowmem pages if the initial LRU shrink fails This will break LRU ordering but may be preferable and faster during memory pressure than skipping LRU pages. Link: http://lkml.kernel.org/r/1467970510-21195-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Kirill A. Shutemov
|
1010245964 |
mm: introduce do_set_pmd()
With postponed page table allocation we have chance to setup huge pages. do_set_pte() calls do_set_pmd() if following criteria met: - page is compound; - pmd entry in pmd_none(); - vma has suitable size and alignment; Link: http://lkml.kernel.org/r/1466021202-61880-12-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Kirill A. Shutemov
|
dd78fedde4 |
rmap: support file thp
Naive approach: on mapping/unmapping the page as compound we update ->_mapcount on each 4k page. That's not efficient, but it's not obvious how we can optimize this. We can look into optimization later. PG_double_map optimization doesn't work for file pages since lifecycle of file pages is different comparing to anon pages: file page can be mapped again at any time. Link: http://lkml.kernel.org/r/1466021202-61880-11-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Minchan Kim
|
b1123ea6d3 |
mm: balloon: use general non-lru movable page feature
Now, VM has a feature to migrate non-lru movable pages so balloon
doesn't need custom migration hooks in migrate.c and compaction.c.
Instead, this patch implements the page->mapping->a_ops->
{isolate|migrate|putback} functions.
With that, we could remove hooks for ballooning in general migration
functions and make balloon compaction simple.
[akpm@linux-foundation.org: compaction.h requires that the includer first include node.h]
Link: http://lkml.kernel.org/r/1464736881-24886-4-git-send-email-minchan@kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Minchan Kim
|
bda807d444 |
mm: migrate: support non-lru movable page migration
We have allowed migration for only LRU pages until now and it was enough to make high-order pages. But recently, embedded system(e.g., webOS, android) uses lots of non-movable pages(e.g., zram, GPU memory) so we have seen several reports about troubles of small high-order allocation. For fixing the problem, there were several efforts (e,g,. enhance compaction algorithm, SLUB fallback to 0-order page, reserved memory, vmalloc and so on) but if there are lots of non-movable pages in system, their solutions are void in the long run. So, this patch is to support facility to change non-movable pages with movable. For the feature, this patch introduces functions related to migration to address_space_operations as well as some page flags. If a driver want to make own pages movable, it should define three functions which are function pointers of struct address_space_operations. 1. bool (*isolate_page) (struct page *page, isolate_mode_t mode); What VM expects on isolate_page function of driver is to return *true* if driver isolates page successfully. On returing true, VM marks the page as PG_isolated so concurrent isolation in several CPUs skip the page for isolation. If a driver cannot isolate the page, it should return *false*. Once page is successfully isolated, VM uses page.lru fields so driver shouldn't expect to preserve values in that fields. 2. int (*migratepage) (struct address_space *mapping, struct page *newpage, struct page *oldpage, enum migrate_mode); After isolation, VM calls migratepage of driver with isolated page. The function of migratepage is to move content of the old page to new page and set up fields of struct page newpage. Keep in mind that you should indicate to the VM the oldpage is no longer movable via __ClearPageMovable() under page_lock if you migrated the oldpage successfully and returns 0. If driver cannot migrate the page at the moment, driver can return -EAGAIN. On -EAGAIN, VM will retry page migration in a short time because VM interprets -EAGAIN as "temporal migration failure". On returning any error except -EAGAIN, VM will give up the page migration without retrying in this time. Driver shouldn't touch page.lru field VM using in the functions. 3. void (*putback_page)(struct page *); If migration fails on isolated page, VM should return the isolated page to the driver so VM calls driver's putback_page with migration failed page. In this function, driver should put the isolated page back to the own data structure. 4. non-lru movable page flags There are two page flags for supporting non-lru movable page. * PG_movable Driver should use the below function to make page movable under page_lock. void __SetPageMovable(struct page *page, struct address_space *mapping) It needs argument of address_space for registering migration family functions which will be called by VM. Exactly speaking, PG_movable is not a real flag of struct page. Rather than, VM reuses page->mapping's lower bits to represent it. #define PAGE_MAPPING_MOVABLE 0x2 page->mapping = page->mapping | PAGE_MAPPING_MOVABLE; so driver shouldn't access page->mapping directly. Instead, driver should use page_mapping which mask off the low two bits of page->mapping so it can get right struct address_space. For testing of non-lru movable page, VM supports __PageMovable function. However, it doesn't guarantee to identify non-lru movable page because page->mapping field is unified with other variables in struct page. As well, if driver releases the page after isolation by VM, page->mapping doesn't have stable value although it has PAGE_MAPPING_MOVABLE (Look at __ClearPageMovable). But __PageMovable is cheap to catch whether page is LRU or non-lru movable once the page has been isolated. Because LRU pages never can have PAGE_MAPPING_MOVABLE in page->mapping. It is also good for just peeking to test non-lru movable pages before more expensive checking with lock_page in pfn scanning to select victim. For guaranteeing non-lru movable page, VM provides PageMovable function. Unlike __PageMovable, PageMovable functions validates page->mapping and mapping->a_ops->isolate_page under lock_page. The lock_page prevents sudden destroying of page->mapping. Driver using __SetPageMovable should clear the flag via __ClearMovablePage under page_lock before the releasing the page. * PG_isolated To prevent concurrent isolation among several CPUs, VM marks isolated page as PG_isolated under lock_page. So if a CPU encounters PG_isolated non-lru movable page, it can skip it. Driver doesn't need to manipulate the flag because VM will set/clear it automatically. Keep in mind that if driver sees PG_isolated page, it means the page have been isolated by VM so it shouldn't touch page.lru field. PG_isolated is alias with PG_reclaim flag so driver shouldn't use the flag for own purpose. [opensource.ganesh@gmail.com: mm/compaction: remove local variable is_lru] Link: http://lkml.kernel.org/r/20160618014841.GA7422@leo-test Link: http://lkml.kernel.org/r/1464736881-24886-3-git-send-email-minchan@kernel.org Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: John Einar Reitan <john.reitan@foss.arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Minchan Kim
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c6c919eb90 |
mm: use put_page() to free page instead of putback_lru_page()
Recently, I got many reports about perfermance degradation in embedded
system(Android mobile phone, webOS TV and so on) and easy fork fail.
The problem was fragmentation caused by zram and GPU driver mainly.
With memory pressure, their pages were spread out all of pageblock and
it cannot be migrated with current compaction algorithm which supports
only LRU pages. In the end, compaction cannot work well so reclaimer
shrinks all of working set pages. It made system very slow and even to
fail to fork easily which requires order-[2 or 3] allocations.
Other pain point is that they cannot use CMA memory space so when OOM
kill happens, I can see many free pages in CMA area, which is not memory
efficient. In our product which has big CMA memory, it reclaims zones
too exccessively to allocate GPU and zram page although there are lots
of free space in CMA so system becomes very slow easily.
To solve these problem, this patch tries to add facility to migrate
non-lru pages via introducing new functions and page flags to help
migration.
struct address_space_operations {
..
..
bool (*isolate_page)(struct page *, isolate_mode_t);
void (*putback_page)(struct page *);
..
}
new page flags
PG_movable
PG_isolated
For details, please read description in "mm: migrate: support non-lru
movable page migration".
Originally, Gioh Kim had tried to support this feature but he moved so I
took over the work. I took many code from his work and changed a little
bit and Konstantin Khlebnikov helped Gioh a lot so he should deserve to
have many credit, too.
And I should mention Chulmin who have tested this patchset heavily so I
can find many bugs from him. :)
Thanks, Gioh, Konstantin and Chulmin!
This patchset consists of five parts.
1. clean up migration
mm: use put_page to free page instead of putback_lru_page
2. add non-lru page migration feature
mm: migrate: support non-lru movable page migration
3. rework KVM memory-ballooning
mm: balloon: use general non-lru movable page feature
4. zsmalloc refactoring for preparing page migration
zsmalloc: keep max_object in size_class
zsmalloc: use bit_spin_lock
zsmalloc: use accessor
zsmalloc: factor page chain functionality out
zsmalloc: introduce zspage structure
zsmalloc: separate free_zspage from putback_zspage
zsmalloc: use freeobj for index
5. zsmalloc page migration
zsmalloc: page migration support
zram: use __GFP_MOVABLE for memory allocation
This patch (of 12):
Procedure of page migration is as follows:
First of all, it should isolate a page from LRU and try to migrate the
page. If it is successful, it releases the page for freeing.
Otherwise, it should put the page back to LRU list.
For LRU pages, we have used putback_lru_page for both freeing and
putback to LRU list. It's okay because put_page is aware of LRU list so
if it releases last refcount of the page, it removes the page from LRU
list. However, It makes unnecessary operations (e.g., lru_cache_add,
pagevec and flags operations. It would be not significant but no worth
to do) and harder to support new non-lru page migration because put_page
isn't aware of non-lru page's data structure.
To solve the problem, we can add new hook in put_page with PageMovable
flags check but it can increase overhead in hot path and needs new
locking scheme to stabilize the flag check with put_page.
So, this patch cleans it up to divide two semantic(ie, put and putback).
If migration is successful, use put_page instead of putback_lru_page and
use putback_lru_page only on failure. That makes code more readable and
doesn't add overhead in put_page.
Comment from Vlastimil
"Yeah, and compaction (perhaps also other migration users) has to drain
the lru pvec... Getting rid of this stuff is worth even by itself."
Link: http://lkml.kernel.org/r/1464736881-24886-2-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Richard Weinberger
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1118dce773 |
mm: Export migrate_page_move_mapping and migrate_page_copy
Export these symbols such that UBIFS can implement ->migratepage. Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Christoph Hellwig <hch@lst.de> |
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David Rientjes
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dfef2ef402 |
mm, migrate: increment fail count on ENOMEM
If page migration fails due to -ENOMEM, nr_failed should still be incremented for proper statistics. This was encountered recently when all page migration vmstats showed 0, and inferred that migrate_pages() was never called, although in reality the first page migration failed because compaction_alloc() failed to find a migration target. This patch increments nr_failed so the vmstat is properly accounted on ENOMEM. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1605191510230.32658@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> 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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Hugh Dickins
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fa9949da59 |
mm: use __SetPageSwapBacked and dont ClearPageSwapBacked
v3.16 commit
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Minchan Kim
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d7e69488bd |
mm/hwpoison: fix wrong num_poisoned_pages accounting
Currently, migration code increses num_poisoned_pages on *failed* migration page as well as successfully migrated one at the trial of memory-failure. It will make the stat wrong. As well, it marks the page as PG_HWPoison even if the migration trial failed. It would mean we cannot recover the corrupted page using memory-failure facility. This patches fixes it. Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.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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Kirill A. Shutemov
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e388466de4 |
mm: make remove_migration_ptes() beyond mm/migration.c
Make remove_migration_ptes() available to be used in split_huge_page(). New parameter 'locked' added: as with try_to_umap() we need a way to indicate that caller holds rmap lock. We also shouldn't try to mlock() pte-mapped huge pages: pte-mapeed THP pages are never mlocked. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.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
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fe896d1878 |
mm: introduce page reference manipulation functions
The success of CMA allocation largely depends on the success of migration and key factor of it is page reference count. Until now, page reference is manipulated by direct calling atomic functions so we cannot follow up who and where manipulate it. Then, it is hard to find actual reason of CMA allocation failure. CMA allocation should be guaranteed to succeed so finding offending place is really important. In this patch, call sites where page reference is manipulated are converted to introduced wrapper function. This is preparation step to add tracepoint to each page reference manipulation function. With this facility, we can easily find reason of CMA allocation failure. There is no functional change in this patch. In addition, this patch also converts reference read sites. It will help a second step that renames page._count to something else and prevents later attempt to direct access to it (Suggested by Andrew). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aneesh Kumar K.V
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458aa76d13 |
mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range
We remove one instace of flush_tlb_range here. That was added by commit
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Johannes Weiner
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74485cf2bc |
mm: migrate: consolidate mem_cgroup_migrate() calls
Rather than scattering mem_cgroup_migrate() calls all over the place, have a single call from a safe place where every migration operation eventually ends up in - migrate_page_copy(). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@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
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6a93ca8fde |
mm: migrate: do not touch page->mem_cgroup of live pages
Changing a page's memcg association complicates dealing with the page, so we want to limit this as much as possible. Page migration e.g. does not have to do that. Just like page cache replacement, it can forcibly charge a replacement page, and then uncharge the old page when it gets freed. Temporarily overcharging the cgroup by a single page is not an issue in practice, and charging is so cheap nowadays that this is much preferrable to the headache of messing with live pages. The only place that still changes the page->mem_cgroup binding of live pages is when pages move along with a task to another cgroup. But that path isolates the page from the LRU, takes the page lock, and the move lock (lock_page_memcg()). That means page->mem_cgroup is always stable in callers that have the page isolated from the LRU or locked. Lighter unlocked paths, like writeback accounting, can use lock_page_memcg(). [akpm@linux-foundation.org: fix build] [vdavydov@virtuozzo.com: fix lockdep splat] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: 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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Vlastimil Babka
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7cd12b4abf |
mm, page_owner: track and print last migrate reason
During migration, page_owner info is now copied with the rest of the page, so the stacktrace leading to free page allocation during migration is overwritten. For debugging purposes, it might be however useful to know that the page has been migrated since its initial allocation. This might happen many times during the lifetime for different reasons and fully tracking this, especially with stacktraces would incur extra memory costs. As a compromise, store and print the migrate_reason of the last migration that occurred to the page. This is enough to distinguish compaction, numa balancing etc. Example page_owner entry after the patch: Page allocated via order 0, mask 0x24200ca(GFP_HIGHUSER_MOVABLE) PFN 628753 type Movable Block 1228 type Movable Flags 0x1fffff80040030(dirty|lru|swapbacked) [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230 [<ffffffff811b6325>] alloc_pages_vma+0xb5/0x250 [<ffffffff81177491>] shmem_alloc_page+0x61/0x90 [<ffffffff8117a438>] shmem_getpage_gfp+0x678/0x960 [<ffffffff8117c2b9>] shmem_fallocate+0x329/0x440 [<ffffffff811de600>] vfs_fallocate+0x140/0x230 [<ffffffff811df434>] SyS_fallocate+0x44/0x70 [<ffffffff8158cc2e>] entry_SYSCALL_64_fastpath+0x12/0x71 Page has been migrated, last migrate reason: compaction Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: 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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Vlastimil Babka
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d435edca92 |
mm, page_owner: copy page owner info during migration
The page_owner mechanism stores gfp_flags of an allocation and stack
trace that lead to it. During page migration, the original information
is practically replaced by the allocation of free page as the migration
target. Arguably this is less useful and might lead to all the
page_owner info for migratable pages gradually converge towards
compaction or numa balancing migrations. It has also lead to
inaccuracies such as one fixed by commit
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Mel Gorman
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8479eba778 |
mm: numa: quickly fail allocations for NUMA balancing on full nodes
Commit |
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Kirill A. Shutemov
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9a982250f7 |
thp: introduce deferred_split_huge_page()
Currently we don't split huge page on partial unmap. It's not an ideal situation. It can lead to memory overhead. Furtunately, we can detect partial unmap on page_remove_rmap(). But we cannot call split_huge_page() from there due to locking context. It's also counterproductive to do directly from munmap() codepath: in many cases we will hit this from exit(2) and splitting the huge page just to free it up in small pages is not what we really want. The patch introduce deferred_split_huge_page() which put the huge page into queue for splitting. The splitting itself will happen when we get memory pressure via shrinker interface. The page will be dropped from list on freeing through compound page destructor. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.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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Kirill A. Shutemov
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4d2fa96548 |
thp, mm: split_huge_page(): caller need to lock page
We're going to use migration entries instead of compound_lock() to stabilize page refcounts. Setup and remove migration entries require page to be locked. Some of split_huge_page() callers already have the page locked. Let's require everybody to lock the page before calling split_huge_page(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.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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Kirill A. Shutemov
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53f9263bab |
mm: rework mapcount accounting to enable 4k mapping of THPs
We're going to allow mapping of individual 4k pages of THP compound. It means we need to track mapcount on per small page basis. Straight-forward approach is to use ->_mapcount in all subpages to track how many time this subpage is mapped with PMDs or PTEs combined. But this is rather expensive: mapping or unmapping of a THP page with PMD would require HPAGE_PMD_NR atomic operations instead of single we have now. The idea is to store separately how many times the page was mapped as whole -- compound_mapcount. This frees up ->_mapcount in subpages to track PTE mapcount. We use the same approach as with compound page destructor and compound order to store compound_mapcount: use space in first tail page, ->mapping this time. Any time we map/unmap whole compound page (THP or hugetlb) -- we increment/decrement compound_mapcount. When we map part of compound page with PTE we operate on ->_mapcount of the subpage. page_mapcount() counts both: PTE and PMD mappings of the page. Basically, we have mapcount for a subpage spread over two counters. It makes tricky to detect when last mapcount for a page goes away. We introduced PageDoubleMap() for this. When we split THP PMD for the first time and there's other PMD mapping left we offset up ->_mapcount in all subpages by one and set PG_double_map on the compound page. These additional references go away with last compound_mapcount. This approach provides a way to detect when last mapcount goes away on per small page basis without introducing new overhead for most common cases. [akpm@linux-foundation.org: fix typo in comment] [mhocko@suse.com: ignore partial THP when moving task] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-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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Kirill A. Shutemov
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d281ee6145 |
rmap: add argument to charge compound page
We're going to allow mapping of individual 4k pages of THP compound page. It means we cannot rely on PageTransHuge() check to decide if map/unmap small page or THP. The patch adds new argument to rmap functions to indicate whether we want to operate on whole compound page or only the small page. [n-horiguchi@ah.jp.nec.com: fix mapcount mismatch in hugepage migration] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Kirill A. Shutemov
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48c935ad88 |
page-flags: define PG_locked behavior on compound pages
lock_page() must operate on the whole compound page. It doesn't make much sense to lock part of compound page. Change code to use head page's PG_locked, if tail page is passed. This patch also gets rid of custom helper functions -- __set_page_locked() and __clear_page_locked(). They are replaced with helpers generated by __SETPAGEFLAG/__CLEARPAGEFLAG. Tail pages to these helper would trigger VM_BUG_ON(). SLUB uses PG_locked as a bit spin locked. IIUC, tail pages should never appear there. VM_BUG_ON() is added to make sure that this assumption is correct. [akpm@linux-foundation.org: fix fs/cifs/file.c] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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71baba4b92 |
mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM
__GFP_WAIT was used to signal that the caller was in atomic context and could not sleep. Now it is possible to distinguish between true atomic context and callers that are not willing to sleep. The latter should clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing __GFP_WAIT behaves differently, there is a risk that people will clear the wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly indicate what it does -- setting it allows all reclaim activity, clearing them prevents it. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@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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Mel Gorman
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d0164adc89 |
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@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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Hugh Dickins
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42cb14b110 |
mm: migrate dirty page without clear_page_dirty_for_io etc
clear_page_dirty_for_io() has accumulated writeback and memcg subtleties since v2.6.16 first introduced page migration; and the set_page_dirty() which completed its migration of PageDirty, later had to be moderated to __set_page_dirty_nobuffers(); then PageSwapBacked had to skip that too. No actual problems seen with this procedure recently, but if you look into what the clear_page_dirty_for_io(page)+set_page_dirty(newpage) is actually achieving, it turns out to be nothing more than moving the PageDirty flag, and its NR_FILE_DIRTY stat from one zone to another. It would be good to avoid a pile of irrelevant decrementations and incrementations, and improper event counting, and unnecessary descent of the radix_tree under tree_lock (to set the PAGECACHE_TAG_DIRTY which radix_tree_replace_slot() left in place anyway). Do the NR_FILE_DIRTY movement, like the other stats movements, while interrupts still disabled in migrate_page_move_mapping(); and don't even bother if the zone is the same. Do the PageDirty movement there under tree_lock too, where old page is frozen and newpage not yet visible: bearing in mind that as soon as newpage becomes visible in radix_tree, an un-page-locked set_page_dirty() might interfere (or perhaps that's just not possible: anything doing so should already hold an additional reference to the old page, preventing its migration; but play safe). But we do still need to transfer PageDirty in migrate_page_copy(), for those who don't go the mapping route through migrate_page_move_mapping(). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@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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Hugh Dickins
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cf4b769abb |
mm: page migration avoid touching newpage until no going back
We have had trouble in the past from the way in which page migration's
newpage is initialized in dribs and drabs - see commit
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Hugh Dickins
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03f15c86c8 |
mm: simplify page migration's anon_vma comment and flow
__unmap_and_move() contains a long stale comment on page_get_anon_vma() and PageSwapCache(), with an odd control flow that's hard to follow. Mostly this reflects our confusion about the lifetime of an anon_vma, in the early days of page migration, before we could take a reference to one. Nowadays this seems quite straightforward: cut it all down to essentials. I cannot see the relevance of swapcache here at all, so don't treat it any differently: I believe the old comment reflects in part our anon_vma confusions, and in part the original v2.6.16 page migration technique, which used actual swap to migrate anon instead of swap-like migration entries. Why should a swapcache page not be migrated with the aid of migration entry ptes like everything else? So lose that comment now, and enable migration entries for swapcache in the next patch. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@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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Hugh Dickins
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5c3f9a6737 |
mm: page migration remove_migration_ptes at lock+unlock level
Clean up page migration a little more by calling remove_migration_ptes() from the same level, on success or on failure, from __unmap_and_move() or from unmap_and_move_huge_page(). Don't reset page->mapping of a PageAnon old page in move_to_new_page(), leave that to when the page is freed. Except for here in page migration, it has been an invariant that a PageAnon (bit set in page->mapping) page stays PageAnon until it is freed, and I think we're safer to keep to that. And with the above rearrangement, it's necessary because zap_pte_range() wants to identify whether a migration entry represents a file or an anon page, to update the appropriate rss stats without waiting on it. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@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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Hugh Dickins
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7db7671f83 |
mm: page migration trylock newpage at same level as oldpage
Clean up page migration a little by moving the trylock of newpage from move_to_new_page() into __unmap_and_move(), where the old page has been locked. Adjust unmap_and_move_huge_page() and balloon_page_migrate() accordingly. But make one kind-of-functional change on the way: whereas trylock of newpage used to BUG() if it failed, now simply return -EAGAIN if so. Cutting out BUG()s is good, right? But, to be honest, this is really to extend the usefulness of the custom put_new_page feature, allowing a pool of new pages to be shared perhaps with racing uses. Use an "else" instead of that "skip_unmap" label. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Hugh Dickins
|
2def7424c9 |
mm: page migration use the put_new_page whenever necessary
I don't know of any problem from the way it's used in our current tree, but there is one defect in page migration's custom put_new_page feature. An unused newpage is expected to be released with the put_new_page(), but there was one MIGRATEPAGE_SUCCESS (0) path which released it with putback_lru_page(): which can be very wrong for a custom pool. Fixed more easily by resetting put_new_page once it won't be needed, than by adding a further flag to modify the rc test. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@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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Hugh Dickins
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14e0f9bcc9 |
mm: correct a couple of page migration comments
It's migrate.c not migration,c, and nowadays putback_movable_pages() not putback_lru_pages(). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Hugh Dickins
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45637bab30 |
mm: rename mem_cgroup_migrate to mem_cgroup_replace_page
After v4.3's commit
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Hugh Dickins
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51afb12ba8 |
mm: page migration fix PageMlocked on migrated pages
Commit
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Vlastimil Babka
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f2f81fb2b7 |
mm, migrate: count pages failing all retries in vmstat and tracepoint
Migration tries up to 10 times to migrate pages that return -EAGAIN until it gives up. If some pages fail all retries, they are counted towards the number of failed pages that migrate_pages() returns. They should also be counted in the /proc/vmstat pgmigrate_fail and in the mm_migrate_pages tracepoint. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Greg Thelen
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0610c25daa |
memcg: fix dirty page migration
The problem starts with a file backed dirty page which is charged to a
memcg. Then page migration is used to move oldpage to newpage.
Migration:
- copies the oldpage's data to newpage
- clears oldpage.PG_dirty
- sets newpage.PG_dirty
- uncharges oldpage from memcg
- charges newpage to memcg
Clearing oldpage.PG_dirty decrements the charged memcg's dirty page
count.
However, because newpage is not yet charged, setting newpage.PG_dirty
does not increment the memcg's dirty page count. After migration
completes newpage.PG_dirty is eventually cleared, often in
account_page_cleaned(). At this time newpage is charged to a memcg so
the memcg's dirty page count is decremented which causes underflow
because the count was not previously incremented by migration. This
underflow causes balance_dirty_pages() to see a very large unsigned
number of dirty memcg pages which leads to aggressive throttling of
buffered writes by processes in non root memcg.
This issue:
- can harm performance of non root memcg buffered writes.
- can report too small (even negative) values in
memory.stat[(total_)dirty] counters of all memcg, including the root.
To avoid polluting migrate.c with #ifdef CONFIG_MEMCG checks, introduce
page_memcg() and set_page_memcg() helpers.
Test:
0) setup and enter limited memcg
mkdir /sys/fs/cgroup/test
echo 1G > /sys/fs/cgroup/test/memory.limit_in_bytes
echo $$ > /sys/fs/cgroup/test/cgroup.procs
1) buffered writes baseline
dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
sync
grep ^dirty /sys/fs/cgroup/test/memory.stat
2) buffered writes with compaction antagonist to induce migration
yes 1 > /proc/sys/vm/compact_memory &
rm -rf /data/tmp/foo
dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
kill %
sync
grep ^dirty /sys/fs/cgroup/test/memory.stat
3) buffered writes without antagonist, should match baseline
rm -rf /data/tmp/foo
dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
sync
grep ^dirty /sys/fs/cgroup/test/memory.stat
(speed, dirty residue)
unpatched patched
1) 841 MB/s 0 dirty pages 886 MB/s 0 dirty pages
2) 611 MB/s -33427456 dirty pages 793 MB/s 0 dirty pages
3) 114 MB/s -33427456 dirty pages 891 MB/s 0 dirty pages
Notice that unpatched baseline performance (1) fell after
migration (3): 841 -> 114 MB/s. In the patched kernel, post
migration performance matches baseline.
Fixes:
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Naoya Horiguchi
|
3aaa76e125 |
mm: migrate: hugetlb: putback destination hugepage to active list
Since commit |
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Vladimir Davydov
|
33c3fc71c8 |
mm: introduce idle page tracking
Knowing the portion of memory that is not used by a certain application or
memory cgroup (idle memory) can be useful for partitioning the system
efficiently, e.g. by setting memory cgroup limits appropriately.
Currently, the only means to estimate the amount of idle memory provided
by the kernel is /proc/PID/{clear_refs,smaps}: the user can clear the
access bit for all pages mapped to a particular process by writing 1 to
clear_refs, wait for some time, and then count smaps:Referenced. However,
this method has two serious shortcomings:
- it does not count unmapped file pages
- it affects the reclaimer logic
To overcome these drawbacks, this patch introduces two new page flags,
Idle and Young, and a new sysfs file, /sys/kernel/mm/page_idle/bitmap.
A page's Idle flag can only be set from userspace by setting bit in
/sys/kernel/mm/page_idle/bitmap at the offset corresponding to the page,
and it is cleared whenever the page is accessed either through page tables
(it is cleared in page_referenced() in this case) or using the read(2)
system call (mark_page_accessed()). Thus by setting the Idle flag for
pages of a particular workload, which can be found e.g. by reading
/proc/PID/pagemap, waiting for some time to let the workload access its
working set, and then reading the bitmap file, one can estimate the amount
of pages that are not used by the workload.
The Young page flag is used to avoid interference with the memory
reclaimer. A page's Young flag is set whenever the Access bit of a page
table entry pointing to the page is cleared by writing to the bitmap file.
If page_referenced() is called on a Young page, it will add 1 to its
return value, therefore concealing the fact that the Access bit was
cleared.
Note, since there is no room for extra page flags on 32 bit, this feature
uses extended page flags when compiled on 32 bit.
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: kpageidle requires an MMU]
[akpm@linux-foundation.org: decouple from page-flags rework]
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.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
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96db800f5d |
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
alloc_pages_exact_node() was introduced in commit |
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Wanpeng Li
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da1b13ccfb |
mm/hwpoison: fix race between soft_offline_page and unpoison_memory
Wanpeng Li reported a race between soft_offline_page() and unpoison_memory(), which causes the following kernel panic: BUG: Bad page state in process bash pfn:97000 page:ffffea00025c0000 count:0 mapcount:1 mapping: (null) index:0x7f4fdbe00 flags: 0x1fffff80080048(uptodate|active|swapbacked) page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set bad because of flags: flags: 0x40(active) Modules linked in: snd_hda_codec_hdmi i915 rpcsec_gss_krb5 nfsv4 dns_resolver bnep rfcomm nfsd bluetooth auth_rpcgss nfs_acl nfs rfkill lockd grace sunrpc i2c_algo_bit drm_kms_helper snd_hda_codec_realtek snd_hda_codec_generic drm snd_hda_intel fscache snd_hda_codec x86_pkg_temp_thermal coretemp kvm_intel snd_hda_core snd_hwdep kvm snd_pcm snd_seq_dummy snd_seq_oss crct10dif_pclmul snd_seq_midi crc32_pclmul snd_seq_midi_event ghash_clmulni_intel snd_rawmidi aesni_intel lrw gf128mul snd_seq glue_helper ablk_helper snd_seq_device cryptd fuse snd_timer dcdbas serio_raw mei_me parport_pc snd mei ppdev i2c_core video lp soundcore parport lpc_ich shpchp mfd_core ext4 mbcache jbd2 sd_mod e1000e ahci ptp libahci crc32c_intel libata pps_core CPU: 3 PID: 2211 Comm: bash Not tainted 4.2.0-rc5-mm1+ #45 Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015 Call Trace: dump_stack+0x48/0x5c bad_page+0xe6/0x140 free_pages_prepare+0x2f9/0x320 ? uncharge_list+0xdd/0x100 free_hot_cold_page+0x40/0x170 __put_single_page+0x20/0x30 put_page+0x25/0x40 unmap_and_move+0x1a6/0x1f0 migrate_pages+0x100/0x1d0 ? kill_procs+0x100/0x100 ? unlock_page+0x6f/0x90 __soft_offline_page+0x127/0x2a0 soft_offline_page+0xa6/0x200 This race is explained like below: CPU0 CPU1 soft_offline_page __soft_offline_page TestSetPageHWPoison unpoison_memory PageHWPoison check (true) TestClearPageHWPoison put_page -> release refcount held by get_hwpoison_page in unpoison_memory put_page -> release refcount held by isolate_lru_page in __soft_offline_page migrate_pages The second put_page() releases refcount held by isolate_lru_page() which will lead to unmap_and_move() releases the last refcount of page and w/ mapcount still 1 since try_to_unmap() is not called if there is only one user map the page. Anyway, the page refcount and mapcount will still mess if the page is mapped by multiple users. This race was introduced by commit |
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Kirill A. Shutemov
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d899844e9c |
mm: fix status code which move_pages() returns for zero page
The manpage for move_pages(2) specifies that status code for zero page is supposed to be -EFAULT. Currently kernel return -ENOENT in this case. follow_page() can do it for us, if we would ask for FOLL_DUMP. The use of FOLL_DUMP also means that the upper layer page tables pages are no longer allocated. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: 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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Naoya Horiguchi
|
4491f71260 |
mm/memory-failure: set PageHWPoison before migrate_pages()
Now page freeing code doesn't consider PageHWPoison as a bad page, so by setting it before completing the page containment, we can prevent the error page from being reused just after successful page migration. I added TTU_IGNORE_HWPOISON for try_to_unmap() to make sure that the page table entry is transformed into migration entry, not to hwpoison entry. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dean Nelson <dnelson@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Hugh Dickins <hughd@google.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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Naoya Horiguchi
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f4c18e6f7b |
mm: check __PG_HWPOISON separately from PAGE_FLAGS_CHECK_AT_*
The race condition addressed in commit |
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Aneesh Kumar K.V
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8809aa2d28 |
mm: clarify that the function operates on hugepage pte
We have confusing functions to clear pmd, pmd_clear_* and pmd_clear. Add _huge_ to pmdp_clear functions so that we are clear that they operate on hugepage pte. We don't bother about other functions like pmdp_set_wrprotect, pmdp_clear_flush_young, because they operate on PTE bits and hence indicate they are operating on hugepage ptes Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Naoya Horiguchi
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add05cecef |
mm: soft-offline: don't free target page in successful page migration
Stress testing showed that soft offline events for a process iterating
"mmap-pagefault-munmap" loop can trigger
VM_BUG_ON(PAGE_FLAGS_CHECK_AT_PREP) in __free_one_page():
Soft offlining page 0x70fe1 at 0x70100008d000
Soft offlining page 0x705fb at 0x70300008d000
page:ffffea0001c3f840 count:0 mapcount:0 mapping: (null) index:0x2
flags: 0x1fffff80800000(hwpoison)
page dumped because: VM_BUG_ON_PAGE(page->flags & ((1 << 25) - 1))
------------[ cut here ]------------
kernel BUG at /src/linux-dev/mm/page_alloc.c:585!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
Modules linked in: cfg80211 rfkill crc32c_intel microcode ppdev parport_pc pcspkr serio_raw virtio_balloon parport i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi floppy
CPU: 3 PID: 1779 Comm: test_base_madv_ Not tainted 4.0.0-v4.0-150511-1451-00009-g82360a3730e6 #139
RIP: free_pcppages_bulk+0x52a/0x6f0
Call Trace:
drain_pages_zone+0x3d/0x50
drain_local_pages+0x1d/0x30
on_each_cpu_mask+0x46/0x80
drain_all_pages+0x14b/0x1e0
soft_offline_page+0x432/0x6e0
SyS_madvise+0x73c/0x780
system_call_fastpath+0x12/0x17
Code: ff 89 45 b4 48 8b 45 c0 48 83 b8 a8 00 00 00 00 0f 85 e3 fb ff ff 0f 1f 00 0f 0b 48 8b 7d 90 48 c7 c6 e8 95 a6 81 e8 e6 32 02 00 <0f> 0b 8b 45 cc 49 89 47 30 41 8b 47 18 83 f8 ff 0f 85 10 ff ff
RIP [<ffffffff811a806a>] free_pcppages_bulk+0x52a/0x6f0
RSP <ffff88007a117d28>
---[ end trace 53926436e76d1f35 ]---
When soft offline successfully migrates page, the source page is supposed
to be freed. But there is a race condition where a source page looks
isolated (i.e. the refcount is 0 and the PageHWPoison is set) but
somewhat linked to pcplist. Then another soft offline event calls
drain_all_pages() and tries to free such hwpoisoned page, which is
forbidden.
This odd page state seems to happen due to the race between put_page() in
putback_lru_page() and __pagevec_lru_add_fn(). But I don't want to play
with tweaking drain code as done in commit
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Naoya Horiguchi
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b3b3a99c53 |
mm/migrate: check-before-clear PageSwapCache
With the page flag sanitization patchset, an invalid usage of ClearPageSwapCache() is detected in migration_page_copy(). migrate_page_copy() is shared by both normal and hugepage (both thp and hugetlb) code path, so let's check PageSwapCache() and clear it if it's set to avoid misuse of the invalid clear operation. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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2a8e700264 |
mm: numa: remove migrate_ratelimited
This code is dead since commit
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Geert Uytterhoeven
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ef2a5153b4 |
mm/migrate: mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3
With gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1) :
mm/migrate.c: In function `migrate_pages':
mm/migrate.c:1148:1: internal compiler error: in push_minipool_fix, at config/arm/arm.c:13500
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccPoM1tr.out file, please attach this to your bugreport.
make[1]: *** [mm/migrate.o] Error 1
make: *** [mm/migrate.o] Error 2
Mark unmap_and_move() (which is used in a single place only) "noinline"
to work around this compiler bug.
[akpm@linux-foundation.org: make it conditional on gcc-4.7.3 and arm]
[khilman@kernel.org: fine-tune compiler versions]
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Kevin Hilman <khilman@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Lina Iyer <lina.iyer@linaro.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
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4d94246699 |
mm: convert p[te|md]_mknonnuma and remaining page table manipulations
With PROT_NONE, the traditional page table manipulation functions are sufficient. [andre.przywara@arm.com: fix compiler warning in pmdp_invalidate()] [akpm@linux-foundation.org: fix build with STRICT_MM_TYPECHECKS] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Jones <davej@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Mackerras <paulus@samba.org> 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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Mel Gorman
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5d83306213 |
mm: numa: do not dereference pmd outside of the lock during NUMA hinting fault
Automatic NUMA balancing depends on being able to protect PTEs to trap a
fault and gather reference locality information. Very broadly speaking
it would mark PTEs as not present and use another bit to distinguish
between NUMA hinting faults and other types of faults. It was
universally loved by everybody and caused no problems whatsoever. That
last sentence might be a lie.
This series is very heavily based on patches from Linus and Aneesh to
replace the existing PTE/PMD NUMA helper functions with normal change
protections. I did alter and add parts of it but I consider them
relatively minor contributions. At their suggestion, acked-bys are in
there but I've no problem converting them to Signed-off-by if requested.
AFAIK, this has received no testing on ppc64 and I'm depending on Aneesh
for that. I tested trinity under kvm-tool and passed and ran a few
other basic tests. At the time of writing, only the short-lived tests
have completed but testing of V2 indicated that long-term testing had no
surprises. In most cases I'm leaving out detail as it's not that
interesting.
specjbb single JVM: There was negligible performance difference in the
benchmark itself for short runs. However, system activity is
higher and interrupts are much higher over time -- possibly TLB
flushes. Migrations are also higher. Overall, this is more overhead
but considering the problems faced with the old approach I think
we just have to suck it up and find another way of reducing the
overhead.
specjbb multi JVM: Negligible performance difference to the actual benchmark
but like the single JVM case, the system overhead is noticeably
higher. Again, interrupts are a major factor.
autonumabench: This was all over the place and about all that can be
reasonably concluded is that it's different but not necessarily
better or worse.
autonumabench
3.18.0-rc5 3.18.0-rc5
mmotm-20141119 protnone-v3r3
User NUMA01 32380.24 ( 0.00%) 21642.92 ( 33.16%)
User NUMA01_THEADLOCAL 22481.02 ( 0.00%) 22283.22 ( 0.88%)
User NUMA02 3137.00 ( 0.00%) 3116.54 ( 0.65%)
User NUMA02_SMT 1614.03 ( 0.00%) 1543.53 ( 4.37%)
System NUMA01 322.97 ( 0.00%) 1465.89 (-353.88%)
System NUMA01_THEADLOCAL 91.87 ( 0.00%) 49.32 ( 46.32%)
System NUMA02 37.83 ( 0.00%) 14.61 ( 61.38%)
System NUMA02_SMT 7.36 ( 0.00%) 7.45 ( -1.22%)
Elapsed NUMA01 716.63 ( 0.00%) 599.29 ( 16.37%)
Elapsed NUMA01_THEADLOCAL 553.98 ( 0.00%) 539.94 ( 2.53%)
Elapsed NUMA02 83.85 ( 0.00%) 83.04 ( 0.97%)
Elapsed NUMA02_SMT 86.57 ( 0.00%) 79.15 ( 8.57%)
CPU NUMA01 4563.00 ( 0.00%) 3855.00 ( 15.52%)
CPU NUMA01_THEADLOCAL 4074.00 ( 0.00%) 4136.00 ( -1.52%)
CPU NUMA02 3785.00 ( 0.00%) 3770.00 ( 0.40%)
CPU NUMA02_SMT 1872.00 ( 0.00%) 1959.00 ( -4.65%)
System CPU usage of NUMA01 is worse but it's an adverse workload on this
machine so I'm reluctant to conclude that it's a problem that matters. On
the other workloads that are sensible on this machine, system CPU usage is
great. Overall time to complete the benchmark is comparable
3.18.0-rc5 3.18.0-rc5
mmotm-20141119protnone-v3r3
User 59612.50 48586.44
System 460.22 1537.45
Elapsed 1442.20 1304.29
NUMA alloc hit 5075182 5743353
NUMA alloc miss 0 0
NUMA interleave hit 0 0
NUMA alloc local 5075174 5743339
NUMA base PTE updates 637061448 443106883
NUMA huge PMD updates 1243434 864747
NUMA page range updates 1273699656 885857347
NUMA hint faults 1658116 1214277
NUMA hint local faults 959487 754113
NUMA hint local percent 57 62
NUMA pages migrated 5467056 61676398
The NUMA pages migrated look terrible but when I looked at a graph of the
activity over time I see that the massive spike in migration activity was
during NUMA01. This correlates with high system CPU usage and could be
simply down to bad luck but any modifications that affect that workload
would be related to scan rates and migrations, not the protection
mechanism. For all other workloads, migration activity was comparable.
Overall, headline performance figures are comparable but the overhead is
higher, mostly in interrupts. To some extent, higher overhead from this
approach was anticipated but not to this degree. It's going to be
necessary to reduce this again with a separate series in the future. It's
still worth going ahead with this series though as it's likely to avoid
constant headaches with Xen and is probably easier to maintain.
This patch (of 10):
A transhuge NUMA hinting fault may find the page is migrating and should
wait until migration completes. The check is race-prone because the pmd
is deferenced outside of the page lock and while the race is tiny, it'll
be larger if the PMD is cleared while marking PMDs for hinting fault.
This patch closes the race.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Naoya Horiguchi
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e66f17ff71 |
mm/hugetlb: take page table lock in follow_huge_pmd()
We have a race condition between move_pages() and freeing hugepages, where
move_pages() calls follow_page(FOLL_GET) for hugepages internally and
tries to get its refcount without preventing concurrent freeing. This
race crashes the kernel, so this patch fixes it by moving FOLL_GET code
for hugepages into follow_huge_pmd() with taking the page table lock.
This patch intentionally removes page==NULL check after pte_page.
This is justified because pte_page() never returns NULL for any
architectures or configurations.
This patch changes the behavior of follow_huge_pmd() for tail pages and
then tail pages can be pinned/returned. So the caller must be changed to
properly handle the returned tail pages.
We could have a choice to add the similar locking to
follow_huge_(addr|pud) for consistency, but it's not necessary because
currently these functions don't support FOLL_GET flag, so let's leave it
for future development.
Here is the reproducer:
$ cat movepages.c
#include <stdio.h>
#include <stdlib.h>
#include <numaif.h>
#define ADDR_INPUT 0x700000000000UL
#define HPS 0x200000
#define PS 0x1000
int main(int argc, char *argv[]) {
int i;
int nr_hp = strtol(argv[1], NULL, 0);
int nr_p = nr_hp * HPS / PS;
int ret;
void **addrs;
int *status;
int *nodes;
pid_t pid;
pid = strtol(argv[2], NULL, 0);
addrs = malloc(sizeof(char *) * nr_p + 1);
status = malloc(sizeof(char *) * nr_p + 1);
nodes = malloc(sizeof(char *) * nr_p + 1);
while (1) {
for (i = 0; i < nr_p; i++) {
addrs[i] = (void *)ADDR_INPUT + i * PS;
nodes[i] = 1;
status[i] = 0;
}
ret = numa_move_pages(pid, nr_p, addrs, nodes, status,
MPOL_MF_MOVE_ALL);
if (ret == -1)
err("move_pages");
for (i = 0; i < nr_p; i++) {
addrs[i] = (void *)ADDR_INPUT + i * PS;
nodes[i] = 0;
status[i] = 0;
}
ret = numa_move_pages(pid, nr_p, addrs, nodes, status,
MPOL_MF_MOVE_ALL);
if (ret == -1)
err("move_pages");
}
return 0;
}
$ cat hugepage.c
#include <stdio.h>
#include <sys/mman.h>
#include <string.h>
#define ADDR_INPUT 0x700000000000UL
#define HPS 0x200000
int main(int argc, char *argv[]) {
int nr_hp = strtol(argv[1], NULL, 0);
char *p;
while (1) {
p = mmap((void *)ADDR_INPUT, nr_hp * HPS, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
if (p != (void *)ADDR_INPUT) {
perror("mmap");
break;
}
memset(p, 0, nr_hp * HPS);
munmap(p, nr_hp * HPS);
}
}
$ sysctl vm.nr_hugepages=40
$ ./hugepage 10 &
$ ./movepages 10 $(pgrep -f hugepage)
Fixes:
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Kirill A. Shutemov
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27ba0644ea |
rmap: drop support of non-linear mappings
We don't create non-linear mappings anymore. Let's drop code which handles them in rmap. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |