1. 24 Jul, 2012 1 commit
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  10. 27 Jun, 2012 1 commit
  11. 05 Jun, 2012 2 commits
  12. 03 Jun, 2012 2 commits
  13. 29 May, 2012 13 commits
    • Hugh Dickins's avatar
      mm/memcg: move reclaim_stat into lruvec · 89abfab1
      Hugh Dickins authored
      With mem_cgroup_disabled() now explicit, it becomes clear that the
      zone_reclaim_stat structure actually belongs in lruvec, per-zone when
      memcg is disabled but per-memcg per-zone when it's enabled.
      
      We can delete mem_cgroup_get_reclaim_stat(), and change
      update_page_reclaim_stat() to update just the one set of stats, the one
      which get_scan_count() will actually use.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@openvz.org>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
      Reviewed-by: default avatarMinchan Kim <minchan@kernel.org>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
      Cc: Glauber Costa <glommer@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      89abfab1
    • Hugh Dickins's avatar
      mm/memcg: scanning_global_lru means mem_cgroup_disabled · c3c787e8
      Hugh Dickins authored
      Although one has to admire the skill with which it has been concealed,
      scanning_global_lru(mz) is actually just an interesting way to test
      mem_cgroup_disabled().  Too many developer hours have been wasted on
      confusing it with global_reclaim(): just use mem_cgroup_disabled().
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@openvz.org>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Acked-by: default avatarGlauber Costa <glommer@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c3c787e8
    • Hugh Dickins's avatar
      memcg swap: use mem_cgroup_uncharge_swap() · 86493009
      Hugh Dickins authored
      That stuff __mem_cgroup_commit_charge_swapin() does with a swap entry, it
      has a name and even a declaration: just use mem_cgroup_uncharge_swap().
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      86493009
    • Hugh Dickins's avatar
      memcg swap: mem_cgroup_move_swap_account never needs fixup · e91cbb42
      Hugh Dickins authored
      The need_fixup arg to mem_cgroup_move_swap_account() is always false,
      so just remove it.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e91cbb42
    • KAMEZAWA Hiroyuki's avatar
      memcg: fix/change behavior of shared anon at moving task · 4b91355e
      KAMEZAWA Hiroyuki authored
      This patch changes memcg's behavior at task_move().
      
      At task_move(), the kernel scans a task's page table and move the changes
      for mapped pages from source cgroup to target cgroup.  There has been a
      bug at handling shared anonymous pages for a long time.
      
      Before patch:
        - The spec says 'shared anonymous pages are not moved.'
        - The implementation was 'shared anonymoys pages may be moved'.
          If page_mapcount <=2, shared anonymous pages's charge were moved.
      
      After patch:
        - The spec says 'all anonymous pages are moved'.
        - The implementation is 'all anonymous pages are moved'.
      
      Considering usage of memcg, this will not affect user's experience.
      'shared anonymous' pages only exists between a tree of processes which
      don't do exec().  Moving one of process without exec() seems not sane.
      For example, libcgroup will not be affected by this change.  (Anyway, no
      one noticed the implementation for a long time...)
      
      Below is a discussion log:
      
       - current spec/implementation are complex
       - Now, shared file caches are moved
       - It adds unclear check as page_mapcount(). To do correct check,
         we should check swap users, etc.
       - No one notice this implementation behavior. So, no one get benefit
         from the design.
       - In general, once task is moved to a cgroup for running, it will not
         be moved....
       - Finally, we have control knob as memory.move_charge_at_immigrate.
      
      Here is a patch to allow moving shared pages, completely. This makes
      memcg simpler and fix current broken code.
      Suggested-by: default avatarHugh Dickins <hughd@google.com>
      Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Glauber Costa <glommer@parallels.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4b91355e
    • Gavin Shan's avatar
      mm/memblock: fix memory leak on extending regions · 181eb394
      Gavin Shan authored
      The overall memblock has been organized into the memory regions and
      reserved regions.  Initially, the memory regions and reserved regions are
      stored in the predetermined arrays of "struct memblock _region".  It's
      possible for the arrays to be enlarged when we have newly added regions,
      but no free space left there.  The policy here is to create double-sized
      array either by slab allocator or memblock allocator.  Unfortunately, we
      didn't free the old array, which might be allocated through slab allocator
      before.  That would cause memory leak.
      
      The patch introduces 2 variables to trace where (slab or memblock) the
      memory and reserved regions come from.  The memory for the memory or
      reserved regions will be deallocated by kfree() if that was allocated by
      slab allocator.  Thus to fix the memory leak issue.
      Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      181eb394
    • Gavin Shan's avatar
      mm/memblock: cleanup on duplicate VA/PA conversion · 4e2f0775
      Gavin Shan authored
      The overall memblock has been organized into the memory regions and
      reserved regions.  Initially, the memory regions and reserved regions are
      stored in the predetermined arrays of "struct memblock _region".  It's
      possible for the arrays to be enlarged when we have newly added regions
      for them, but no enough space there.  Under the situation, We will created
      double-sized array to meet the requirement.  However, the original
      implementation converted the VA (Virtual Address) of the newly allocated
      array of regions to PA (Physical Address), then translate back when we
      allocates the new array from slab.  That's actually unnecessary.
      
      The patch removes the duplicate VA/PA conversion.
      Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e2f0775
    • Pravin B Shelar's avatar
      mm: fix slab->page flags corruption · 5bf5f03c
      Pravin B Shelar authored
      Transparent huge pages can change page->flags (PG_compound_lock) without
      taking Slab lock.  Since THP can not break slab pages we can safely access
      compound page without taking compound lock.
      
      Specifically this patch fixes a race between compound_unlock() and slab
      functions which perform page-flags updates.  This can occur when
      get_page()/put_page() is called on a page from slab.
      
      [akpm@linux-foundation.org: tweak comment text, fix comment layout, fix label indenting]
      Reported-by: default avatarAmey Bhide <abhide@nicira.com>
      Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
      Reviewed-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Pekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5bf5f03c
    • KyongHo's avatar
      mm: fix faulty initialization in vmalloc_init() · dbda591d
      KyongHo authored
      The transfer of ->flags causes some of the static mapping virtual
      addresses to be prematurely freed (before the mapping is removed) because
      VM_LAZY_FREE gets "set" if tmp->flags has VM_IOREMAP set.  This might
      cause subsequent vmalloc/ioremap calls to fail because it might allocate
      one of the freed virtual address ranges that aren't unmapped.
      
      va->flags has different types of flags from tmp->flags.  If a region with
      VM_IOREMAP set is registered with vm_area_add_early(), it will be removed
      by __purge_vmap_area_lazy().
      
      Fix vmalloc_init() to correctly initialize vmap_area for the given
      vm_struct.
      
      Also initialise va->vm.  If it is not set, find_vm_area() for the early
      vm regions will always fail.
      Signed-off-by: default avatarKyongHo Cho <pullip.cho@samsung.com>
      Cc: "Olav Haugan" <ohaugan@codeaurora.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dbda591d
    • Andrea Arcangeli's avatar
      mm: pmd_read_atomic: fix 32bit PAE pmd walk vs pmd_populate SMP race condition · 26c19178
      Andrea Arcangeli authored
      When holding the mmap_sem for reading, pmd_offset_map_lock should only
      run on a pmd_t that has been read atomically from the pmdp pointer,
      otherwise we may read only half of it leading to this crash.
      
      PID: 11679  TASK: f06e8000  CPU: 3   COMMAND: "do_race_2_panic"
       #0 [f06a9dd8] crash_kexec at c049b5ec
       #1 [f06a9e2c] oops_end at c083d1c2
       #2 [f06a9e40] no_context at c0433ded
       #3 [f06a9e64] bad_area_nosemaphore at c043401a
       #4 [f06a9e6c] __do_page_fault at c0434493
       #5 [f06a9eec] do_page_fault at c083eb45
       #6 [f06a9f04] error_code (via page_fault) at c083c5d5
          EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP:
          00000000
          DS:  007b     ESI: 9e201000 ES:  007b     EDI: 01fb4700 GS:  00e0
          CS:  0060     EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246
       #7 [f06a9f38] _spin_lock at c083bc14
       #8 [f06a9f44] sys_mincore at c0507b7d
       #9 [f06a9fb0] system_call at c083becd
                               start           len
          EAX: ffffffda  EBX: 9e200000  ECX: 00001000  EDX: 6228537f
          DS:  007b      ESI: 00000000  ES:  007b      EDI: 003d0f00
          SS:  007b      ESP: 62285354  EBP: 62285388  GS:  0033
          CS:  0073      EIP: 00291416  ERR: 000000da  EFLAGS: 00000286
      
      This should be a longstanding bug affecting x86 32bit PAE without THP.
      Only archs with 64bit large pmd_t and 32bit unsigned long should be
      affected.
      
      With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad()
      would partly hide the bug when the pmd transition from none to stable,
      by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is
      enabled a new set of problem arises by the fact could then transition
      freely in any of the none, pmd_trans_huge or pmd_trans_stable states.
      So making the barrier in pmd_none_or_trans_huge_or_clear_bad()
      unconditional isn't good idea and it would be a flakey solution.
      
      This should be fully fixed by introducing a pmd_read_atomic that reads
      the pmd in order with THP disabled, or by reading the pmd atomically
      with cmpxchg8b with THP enabled.
      
      Luckily this new race condition only triggers in the places that must
      already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix
      is localized there but this bug is not related to THP.
      
      NOTE: this can trigger on x86 32bit systems with PAE enabled with more
      than 4G of ram, otherwise the high part of the pmd will never risk to be
      truncated because it would be zero at all times, in turn so hiding the
      SMP race.
      
      This bug was discovered and fully debugged by Ulrich, quote:
      
      ----
      [..]
      pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and
      eax.
      
          496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t
          *pmd)
          497 {
          498         /* depend on compiler for an atomic pmd read */
          499         pmd_t pmdval = *pmd;
      
                                      // edi = pmd pointer
      0xc0507a74 <sys_mincore+548>:   mov    0x8(%esp),%edi
      ...
                                      // edx = PTE page table high address
      0xc0507a84 <sys_mincore+564>:   mov    0x4(%edi),%edx
      ...
                                      // eax = PTE page table low address
      0xc0507a8e <sys_mincore+574>:   mov    (%edi),%eax
      
      [..]
      
      Please note that the PMD is not read atomically. These are two "mov"
      instructions where the high order bits of the PMD entry are fetched
      first. Hence, the above machine code is prone to the following race.
      
      -  The PMD entry {high|low} is 0x0000000000000000.
         The "mov" at 0xc0507a84 loads 0x00000000 into edx.
      
      -  A page fault (on another CPU) sneaks in between the two "mov"
         instructions and instantiates the PMD.
      
      -  The PMD entry {high|low} is now 0x00000003fda38067.
         The "mov" at 0xc0507a8e loads 0xfda38067 into eax.
      ----
      Reported-by: default avatarUlrich Obergfell <uobergfe@redhat.com>
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Petr Matousek <pmatouse@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      26c19178
    • David Rientjes's avatar
      mm, oom: normalize oom scores to oom_score_adj scale only for userspace · a7f638f9
      David Rientjes authored
      The oom_score_adj scale ranges from -1000 to 1000 and represents the
      proportion of memory available to the process at allocation time.  This
      means an oom_score_adj value of 300, for example, will bias a process as
      though it was using an extra 30.0% of available memory and a value of
      -350 will discount 35.0% of available memory from its usage.
      
      The oom killer badness heuristic also uses this scale to report the oom
      score for each eligible process in determining the "best" process to
      kill.  Thus, it can only differentiate each process's memory usage by
      0.1% of system RAM.
      
      On large systems, this can end up being a large amount of memory: 256MB
      on 256GB systems, for example.
      
      This can be fixed by having the badness heuristic to use the actual
      memory usage in scoring threads and then normalizing it to the
      oom_score_adj scale for userspace.  This results in better comparison
      between eligible threads for kill and no change from the userspace
      perspective.
      Suggested-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Tested-by: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a7f638f9
    • Satoru Moriya's avatar
      mm: avoid swapping out with swappiness==0 · fe35004f
      Satoru Moriya authored
      Sometimes we'd like to avoid swapping out anonymous memory.  In
      particular, avoid swapping out pages of important process or process
      groups while there is a reasonable amount of pagecache on RAM so that we
      can satisfy our customers' requirements.
      
      OTOH, we can control how aggressive the kernel will swap memory pages with
      /proc/sys/vm/swappiness for global and
      /sys/fs/cgroup/memory/memory.swappiness for each memcg.
      
      But with current reclaim implementation, the kernel may swap out even if
      we set swappiness=0 and there is pagecache in RAM.
      
      This patch changes the behavior with swappiness==0.  If we set
      swappiness==0, the kernel does not swap out completely (for global reclaim
      until the amount of free pages and filebacked pages in a zone has been
      reduced to something very very small (nr_free + nr_filebacked < high
      watermark)).
      Signed-off-by: default avatarSatoru Moriya <satoru.moriya@hds.com>
      Acked-by: default avatarMinchan Kim <minchan@kernel.org>
      Reviewed-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarJerome Marchand <jmarchan@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fe35004f
    • Dave Hansen's avatar
      hugetlb: fix resv_map leak in error path · c50ac050
      Dave Hansen authored
      When called for anonymous (non-shared) mappings, hugetlb_reserve_pages()
      does a resv_map_alloc().  It depends on code in hugetlbfs's
      vm_ops->close() to release that allocation.
      
      However, in the mmap() failure path, we do a plain unmap_region() without
      the remove_vma() which actually calls vm_ops->close().
      
      This is a decent fix.  This leak could get reintroduced if new code (say,
      after hugetlb_reserve_pages() in hugetlbfs_file_mmap()) decides to return
      an error.  But, I think it would have to unroll the reservation anyway.
      
      Christoph's test case:
      
      	http://marc.info/?l=linux-mm&m=133728900729735
      
      This patch applies to 3.4 and later.  A version for earlier kernels is at
      https://lkml.org/lkml/2012/5/22/418.
      Signed-off-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
      Acked-by: default avatarMel Gorman <mel@csn.ul.ie>
      Acked-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Reported-by: default avatarChristoph Lameter <cl@linux.com>
      Tested-by: default avatarChristoph Lameter <cl@linux.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: <stable@vger.kernel.org>	[2.6.32+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c50ac050