linux_old1/mm
Dave Hansen ef6c5be658 fix incorrect NR_FREE_PAGES accounting (appears like memory leak)
There have been some 3.7-rc reports of vm issues, including some kswapd
bugs and, more importantly, some memory "leaks":

	http://www.spinics.net/lists/linux-mm/msg46187.html
	https://bugzilla.kernel.org/show_bug.cgi?id=50181

Commit 1fb3f8ca0e ("mm: compaction: capture a suitable high-order page
immediately when it is made available") took split_free_page() and
reused it for the compaction code.  It does something curious with
capture_free_page() (previously known as split_free_page()):

  int capture_free_page(struct page *page, int alloc_order,
  ...
          __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));

  -       /* Split into individual pages */
  -       set_page_refcounted(page);
  -       split_page(page, order);
  +       if (alloc_order != order)
  +               expand(zone, page, alloc_order, order,
  +                       &zone->free_area[order], migratetype);

Note that expand() puts the pages _back_ in the allocator, but it does
not bump NR_FREE_PAGES.  We "return" 'alloc_order' worth of pages, but
we accounted for removing 'order' in the __mod_zone_page_state() call.

For the old split_page()-style use (order==alloc_order) the bug will not
trigger.  But, when called from the compaction code where we
occasionally get a larger page out of the buddy allocator than we need,
we will run in to this.

This patch simply changes the NR_FREE_PAGES manipulation to the correct
'alloc_order' instead of 'order'.

I've been able to repeatedly trigger this in my testing environment.
The amount "leaked" very closely tracks the imbalance I see in buddy
pages vs.  NR_FREE_PAGES.  I have confirmed that this patch fixes the
imbalance

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-21 12:33:16 -10:00
..
Kconfig mm: enable CONFIG_COMPACTION by default 2012-10-09 16:22:53 +09:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
Makefile mm: replace vma prio_tree with an interval tree 2012-10-09 16:22:39 +09:00
backing-dev.c backing-dev: use kstrto* in preference to simple_strtoul 2012-08-25 16:58:14 +08:00
bootmem.c revert "mm: fix-up zone present pages" 2012-11-16 14:33:04 -08:00
bounce.c bounce: allow use of bounce pool via config option 2012-07-18 16:40:35 -04:00
cleancache.c ->encode_fh() API change 2012-05-29 23:28:33 -04:00
compaction.c mm: compaction: correct the nr_strict va isolated check for CMA 2012-10-19 14:07:47 -07:00
debug-pagealloc.c mm, x86: Remove debug_pagealloc_enabled 2011-12-06 09:24:07 +01:00
dmapool.c mm: fix implicit stat.h usage in dmapool.c 2011-10-31 09:20:12 -04:00
fadvise.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c readahead: fault retry breaks mmap file read random detection 2012-10-09 16:22:47 +09:00
filemap_xip.c mm: move all mmu notifier invocations to be done outside the PT lock 2012-10-09 16:22:58 +09:00
fremap.c remap_file_pages: correctly handle the case of a NULL vm_ops pointer 2012-10-19 13:37:57 -07:00
frontswap.c frontswap: support exclusive gets if tmem backend is capable 2012-09-21 10:38:12 -04:00
highmem.c mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address 2012-11-16 14:33:04 -08:00
huge_memory.c mm: huge_memory: Fix build error. 2012-10-15 07:59:15 -07:00
hugetlb.c mm: document PageHuge somewhat 2012-10-09 16:23:03 +09:00
hugetlb_cgroup.c hugetlb/cgroup: remove exclude and wakeup rmdir calls from migrate 2012-07-31 18:42:41 -07:00
hwpoison-inject.c memcg: rename config variables 2012-07-31 18:42:43 -07:00
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm, thp: fix mlock statistics 2012-10-09 16:23:03 +09:00
interval_tree.c mm: add CONFIG_DEBUG_VM_RB build option 2012-10-09 16:22:42 +09:00
kmemcheck.c
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c kmemleak: use rbtree instead of prio tree 2012-10-09 16:22:39 +09:00
ksm.c mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end 2012-10-09 16:22:58 +09:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c mm: prepare VM_DONTDUMP for using in drivers 2012-10-09 16:22:18 +09:00
memblock.c x86, mm: Trim memory in memblock to be page aligned 2012-10-24 11:52:21 -07:00
memcontrol.c memcg: fix hotplugged memory zone oops 2012-11-16 14:33:04 -08:00
memory-failure.c mm anon rmap: replace same_anon_vma linked list with an interval tree. 2012-10-09 16:22:41 +09:00
memory.c mm: fix build warning for uninitialized value 2012-11-16 14:33:03 -08:00
memory_hotplug.c revert "mm: fix-up zone present pages" 2012-11-16 14:33:04 -08:00
mempolicy.c mm, mempolicy: fix printing stack contents in numa_maps 2012-10-16 18:00:50 -07:00
mempool.c mempool: add @gfp_mask to mempool_create_node() 2012-06-25 11:53:47 +02:00
migrate.c mm: memcg: fix compaction/migration failing due to memcg limits 2012-07-31 18:42:48 -07:00
mincore.c mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode 2012-03-21 17:54:54 -07:00
mlock.c mm, thp: fix mlock statistics 2012-10-09 16:23:03 +09:00
mm_init.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mmap.c mm: add anon_vma_lock to validate_mm() 2012-11-16 14:33:03 -08:00
mmu_context.c mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat() 2012-03-21 17:54:59 -07:00
mmu_notifier.c mm/mmu_notifier: allocate mmu_notifier in advance 2012-10-25 14:37:53 -07:00
mmzone.c memcg: fix hotplugged memory zone oops 2012-11-16 14:33:04 -08:00
mprotect.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-03-22 09:04:48 -07:00
mremap.c mm: move all mmu notifier invocations to be done outside the PT lock 2012-10-09 16:22:58 +09:00
msync.c
nobootmem.c revert "mm: fix-up zone present pages" 2012-11-16 14:33:04 -08:00
nommu.c mm: replace vma prio_tree with an interval tree 2012-10-09 16:22:39 +09:00
oom_kill.c oom: remove deprecated oom_adj 2012-10-09 16:22:24 +09:00
page-writeback.c CPU hotplug, writeback: Don't call writeback_set_ratelimit() too often during hotplug 2012-09-28 20:27:49 +08:00
page_alloc.c fix incorrect NR_FREE_PAGES accounting (appears like memory leak) 2012-11-21 12:33:16 -10:00
page_cgroup.c memcg: rename config variables 2012-07-31 18:42:43 -07:00
page_io.c mm: add support for direct_IO to highmem pages 2012-07-31 18:42:47 -07:00
page_isolation.c mm/page_alloc: refactor out __alloc_contig_migrate_alloc() 2012-10-09 16:22:52 +09:00
pagewalk.c mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
percpu-km.c percpu: clear memory allocated with the km allocator 2010-10-02 10:28:42 +03:00
percpu-vm.c mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
percpu.c sections: fix section conflicts in mm/percpu.c 2012-10-06 03:04:44 +09:00
pgtable-generic.c thp: introduce pmdp_invalidate() 2012-10-09 16:22:29 +09:00
process_vm_access.c aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector() 2012-05-31 17:49:32 -07:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
rmap.c mm: fix XFS oops due to dirty pages without buffers on s390 2012-10-25 14:37:52 -07:00
shmem.c tmpfs: change final i_blocks BUG to WARNING 2012-11-16 14:33:04 -08:00
slab.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2012-10-07 07:53:13 +09:00
slab.h Revert "mm/sl[aou]b: Move sysfs_slab_add to common" 2012-09-05 12:07:44 +03:00
slab_common.c mm, slab: release slab_mutex earlier in kmem_cache_destroy() 2012-10-10 09:25:08 +03:00
slob.c Merge branch 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc into fixes 2012-10-19 15:40:18 -07:00
slub.c Merge branch 'slab/common-for-cgroups' into slab/for-linus 2012-10-03 09:56:37 +03:00
sparse-vmemmap.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
sparse.c mm/sparse: remove index_init_lock 2012-07-31 18:42:49 -07:00
swap.c mm: remove vma arg from page_evictable 2012-10-09 16:22:55 +09:00
swap_state.c mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages 2012-07-31 18:42:47 -07:00
swapfile.c swapfile: fix name leak in swapoff 2012-11-16 14:33:04 -08:00
truncate.c mm: use clear_page_mlock() in page_remove_rmap() 2012-10-09 16:22:56 +09:00
util.c mm: Use __do_krealloc to do the krealloc job 2012-09-04 10:22:58 +03:00
vmalloc.c mm: use %pK for /proc/vmallocinfo 2012-10-09 16:23:03 +09:00
vmscan.c mm: revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" 2012-11-16 14:33:04 -08:00
vmstat.c mm: remove unevictable_pgs_mlockfreed 2012-10-09 16:22:59 +09:00