linux/mm
Hugh Dickins 80e1482260 ksm: share anon page without allocating
When ksm pages were unswappable, it made no sense to include them in mem
cgroup accounting; but now that they are swappable (although I see no
strict logical connection) the principle of least surprise implies that
they should be accounted (with the usual dissatisfaction, that a shared
page is accounted to only one of the cgroups using it).

This patch was intended to add mem cgroup accounting where necessary; but
turned inside out, it now avoids allocating a ksm page, instead upgrading
an anon page to ksm - which brings its existing mem cgroup accounting with
it.  Thus mem cgroups don't appear in the patch at all.

This upgrade from PageAnon to PageKsm takes place under page lock (via a
somewhat hacky NULL kpage interface), and audit showed only one place
which needed to cope with the race - page_referenced() is sometimes used
without page lock, so page_lock_anon_vma() needs an ACCESS_ONCE() to be
sure of getting anon_vma and flags together (no problem if the page goes
ksm an instant after, the integrity of that anon_vma list is unaffected).

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wright <chrisw@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:19 -08:00
..
Kconfig mm: stop ptlock enlarging struct page 2009-12-15 08:53:17 -08:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
Makefile percpu: kill legacy percpu allocator 2009-10-02 13:29:29 +09:00
backing-dev.c flusher: Fix PF_FROZEN race 2009-12-03 13:49:43 +01:00
bootmem.c bootmem: Add free_bootmem_late() 2009-11-10 12:31:43 +01:00
bounce.c block: remove some includings of blktrace_api.h 2009-06-16 11:19:36 +02:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
fadvise.c readahead: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
failslab.c kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c 2009-04-03 12:23:01 +02:00
filemap.c kill wait_on_page_writeback_range 2009-12-10 15:02:50 +01:00
filemap_xip.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
fremap.c
highmem.c highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE 2009-11-10 04:15:47 +01:00
hugetlb.c mm: add gfp flags for NODEMASK_ALLOC slab allocations 2009-12-15 08:53:13 -08:00
hwpoison-inject.c HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs 2009-09-16 11:50:17 +02:00
init-mm.c mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
internal.h ksm: fix mlockfreed to munlocked 2009-12-15 08:53:19 -08:00
kmemcheck.c kmemcheck: add hooks for the page allocator 2009-06-15 15:48:33 +02:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c tree-wide: fix typos "aquire" -> "acquire", "cumsumed" -> "consumed" 2009-11-09 09:40:57 +01:00
ksm.c ksm: share anon page without allocating 2009-12-15 08:53:19 -08:00
maccess.c [S390] maccess: add weak attribute to probe_kernel_write 2009-06-12 10:27:37 +02:00
madvise.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-09-24 07:53:22 -07:00
memcontrol.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
memory-failure.c mm: CONFIG_MMU for PG_mlocked 2009-12-15 08:53:17 -08:00
memory.c ksm: let shared pages be swappable 2009-12-15 08:53:19 -08:00
memory_hotplug.c mm: clear node in N_HIGH_MEMORY and stop kswapd when all memory is offlined 2009-12-15 08:53:13 -08:00
mempolicy.c hugetlb: derive huge pages nodes allowed from task mempolicy 2009-12-15 08:53:12 -08:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm: define PAGE_MAPPING_FLAGS 2009-12-15 08:53:17 -08:00
mincore.c
mlock.c ksm: fix mlockfreed to munlocked 2009-12-15 08:53:19 -08:00
mm_init.c
mmap.c mmap: don't return ENOMEM when mapcount is temporarily exceeded in munmap() 2009-12-15 08:53:11 -08:00
mmu_context.c mm: reduce atomic use on use_mm fast path 2009-09-22 07:17:42 -07:00
mmu_notifier.c ksm: add mmu_notifier set_pte_at_notify() 2009-09-22 07:17:31 -07:00
mmzone.c [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 2009-05-18 11:22:24 +01:00
mprotect.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
mremap.c Take arch_mmap_check() into get_unmapped_area() 2009-12-11 06:44:58 -05:00
msync.c
nommu.c NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff() 2009-10-31 12:11:37 -07:00
oom_kill.c oom: dump stack and VM state when oom killer panics 2009-12-15 08:53:10 -08:00
page-writeback.c writeback: remove unused nonblocking and congestion checks 2009-12-03 13:54:25 +01:00
page_alloc.c mm: CONFIG_MMU for PG_mlocked 2009-12-15 08:53:17 -08:00
page_cgroup.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
page_io.c swap: rework map_swap_page() again 2009-12-15 08:53:16 -08:00
page_isolation.c
pagewalk.c
percpu.c Merge branch 'for-linus' into for-next 2009-12-08 10:02:12 +09:00
prio_tree.c
quicklist.c cpumask: use new-style cpumask ops in mm/quicklist. 2009-09-24 09:34:52 +09:30
readahead.c readahead: introduce context readahead algorithm 2009-06-16 19:47:30 -07:00
rmap.c ksm: share anon page without allocating 2009-12-15 08:53:19 -08:00
shmem.c swap_info: note SWAP_MAP_SHMEM 2009-12-15 08:53:16 -08:00
shmem_acl.c shmfs: use 'check_acl' instead of 'permission' 2009-09-08 11:08:46 -07:00
slab.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-14 10:13:22 -08:00
slob.c slab: remove duplicate kmem_cache_init_late() declarations 2009-08-06 11:36:25 +03:00
slub.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-14 10:13:22 -08:00
sparse-vmemmap.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
sparse.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
swap.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
swap_state.c mm: add_to_swap_cache() does not return -EEXIST 2009-09-22 07:17:35 -07:00
swapfile.c ksm: let shared pages be swappable 2009-12-15 08:53:19 -08:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c mm: fix comments for invalidate_inode_pages2() 2009-12-04 15:39:48 +01:00
util.c fix a struct file leak in do_mmap_pgoff() 2009-12-11 06:44:57 -05:00
vmalloc.c vmalloc(): adjust gfp mask passed on nested vmalloc() invocation 2009-12-15 08:53:13 -08:00
vmscan.c vmscan: make consistent of reclaim bale out between do_try_to_free_page and shrink_zone 2009-12-15 08:53:18 -08:00
vmstat.c vmscan: stop kswapd waiting on congestion when the min watermark is not being met 2009-12-15 08:53:16 -08:00