1. 17 Aug, 2015 1 commit
  2. 13 Feb, 2015 1 commit
    • Vladimir Davydov's avatar
      vmscan: per memory cgroup slab shrinkers · cb731d6c
      Vladimir Davydov authored
      This patch adds SHRINKER_MEMCG_AWARE flag.  If a shrinker has this flag
      set, it will be called per memory cgroup.  The memory cgroup to scan
      objects from is passed in shrink_control->memcg.  If the memory cgroup
      is NULL, a memcg aware shrinker is supposed to scan objects from the
      global list.  Unaware shrinkers are only called on global pressure with
      memcg=NULL.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Glauber Costa <glommer@gmail.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Tejun Heo <tj@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cb731d6c
  3. 13 Dec, 2014 1 commit
    • Johannes Weiner's avatar
      mm: vmscan: invoke slab shrinkers from shrink_zone() · 6b4f7799
      Johannes Weiner authored
      The slab shrinkers are currently invoked from the zonelist walkers in
      kswapd, direct reclaim, and zone reclaim, all of which roughly gauge the
      eligible LRU pages and assemble a nodemask to pass to NUMA-aware
      shrinkers, which then again have to walk over the nodemask.  This is
      redundant code, extra runtime work, and fairly inaccurate when it comes to
      the estimation of actually scannable LRU pages.  The code duplication will
      only get worse when making the shrinkers cgroup-aware and requiring them
      to have out-of-band cgroup hierarchy walks as well.
      
      Instead, invoke the shrinkers from shrink_zone(), which is where all
      reclaimers end up, to avoid this duplication.
      
      Take the count for eligible LRU pages out of get_scan_count(), which
      considers many more factors than just the availability of swap space, like
      zone_reclaimable_pages() currently does.  Accumulate the number over all
      visited lruvecs to get the per-zone value.
      
      Some nodes have multiple zones due to memory addressing restrictions.  To
      avoid putting too much pressure on the shrinkers, only invoke them once
      for each such node, using the class zone of the allocation as the pivot
      zone.
      
      For now, this integrates the slab shrinking better into the reclaim logic
      and gets rid of duplicative invocations from kswapd, direct reclaim, and
      zone reclaim.  It also prepares for cgroup-awareness, allowing
      memcg-capable shrinkers to be added at the lruvec level without much
      duplication of both code and runtime work.
      
      This changes kswapd behavior, which used to invoke the shrinkers for each
      zone, but with scan ratios gathered from the entire node, resulting in
      meaningless pressure quantities on multi-zone nodes.
      
      Zone reclaim behavior also changes.  It used to shrink slabs until the
      same amount of pages were shrunk as were reclaimed from the LRUs.  Now it
      merely invokes the shrinkers once with the zone's scan ratio, which makes
      the shrinkers go easier on caches that implement aging and would prefer
      feeding back pressure from recently used slab objects to unused LRU pages.
      
      [vdavydov@parallels.com: assure class zone is populated]
      Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6b4f7799
  4. 06 Jun, 2014 1 commit
  5. 03 Apr, 2014 1 commit
  6. 10 Sep, 2013 1 commit
    • Dave Chinner's avatar
      shrinker: add node awareness · 0ce3d744
      Dave Chinner authored
      Pass the node of the current zone being reclaimed to shrink_slab(),
      allowing the shrinker control nodemask to be set appropriately for node
      aware shrinkers.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarGlauber Costa <glommer@openvz.org>
      Acked-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
      Cc: Arve Hjønnevåg <arve@android.com>
      Cc: Carlos Maiolino <cmaiolino@redhat.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Chuck Lever <chuck.lever@oracle.com>
      Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Gleb Natapov <gleb@redhat.com>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: J. Bruce Fields <bfields@redhat.com>
      Cc: Jan Kara <jack@suse.cz>
      Cc: Jerome Glisse <jglisse@redhat.com>
      Cc: John Stultz <john.stultz@linaro.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Kent Overstreet <koverstreet@google.com>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Thomas Hellstrom <thellstrom@vmware.com>
      Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      0ce3d744
  7. 25 May, 2011 2 commits
  8. 25 Mar, 2011 2 commits
    • Dave Chinner's avatar
      fs: move i_sb_list out from under inode_lock · 55fa6091
      Dave Chinner authored
      Protect the per-sb inode list with a new global lock
      inode_sb_list_lock and use it to protect the list manipulations and
      traversals. This lock replaces the inode_lock as the inodes on the
      list can be validity checked while holding the inode->i_lock and
      hence the inode_lock is no longer needed to protect the list.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      55fa6091
    • Dave Chinner's avatar
      fs: protect inode->i_state with inode->i_lock · 250df6ed
      Dave Chinner authored
      Protect inode state transitions and validity checks with the
      inode->i_lock. This enables us to make inode state transitions
      independently of the inode_lock and is the first step to peeling
      away the inode_lock from the code.
      
      This requires that __iget() is done atomically with i_state checks
      during list traversals so that we don't race with another thread
      marking the inode I_FREEING between the state check and grabbing the
      reference.
      
      Also remove the unlock_new_inode() memory barrier optimisation
      required to avoid taking the inode_lock when clearing I_NEW.
      Simplify the code by simply taking the inode->i_lock around the
      state change and wakeup. Because the wakeup is no longer tricky,
      remove the wake_up_inode() function and open code the wakeup where
      necessary.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      250df6ed
  9. 24 Mar, 2011 1 commit
  10. 09 Aug, 2010 1 commit
    • Al Viro's avatar
      simplify checks for I_CLEAR/I_FREEING · a4ffdde6
      Al Viro authored
      add I_CLEAR instead of replacing I_FREEING with it.  I_CLEAR is
      equivalent to I_FREEING for almost all code looking at either;
      it's there to keep track of having called clear_inode() exactly
      once per inode lifetime, at some point after having set I_FREEING.
      I_CLEAR and I_FREEING never get set at the same time with the
      current code, so we can switch to setting i_flags to I_FREEING | I_CLEAR
      instead of I_CLEAR without loss of information.  As the result of
      such change, checks become simpler and the amount of code that needs
      to know about I_CLEAR shrinks a lot.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      a4ffdde6
  11. 21 May, 2010 4 commits
  12. 24 Sep, 2009 1 commit
  13. 17 Jun, 2009 1 commit
  14. 03 Apr, 2009 1 commit
    • Wu Fengguang's avatar
      vfs: skip I_CLEAR state inodes · b6fac63c
      Wu Fengguang authored
      clear_inode() will switch inode state from I_FREEING to I_CLEAR, and do so
      _outside_ of inode_lock.  So any I_FREEING testing is incomplete without a
      coupled testing of I_CLEAR.
      
      So add I_CLEAR tests to drop_pagecache_sb(), generic_sync_sb_inodes() and
      add_dquot_ref().
      
      Masayoshi MIZUMA discovered the bug in drop_pagecache_sb() and Jan Kara
      reminds fixing the other two cases.
      
      Masayoshi MIZUMA has a nice panic flow:
      
      =====================================================================
                  [process A]               |        [process B]
       |                                    |
       |    prune_icache()                  | drop_pagecache()
       |      spin_lock(&inode_lock)        |   drop_pagecache_sb()
       |      inode->i_state |= I_FREEING;  |       |
       |      spin_unlock(&inode_lock)      |       V
       |          |                         |     spin_lock(&inode_lock)
       |          V                         |         |
       |      dispose_list()                |         |
       |        list_del()                  |         |
       |        clear_inode()               |         |
       |          inode->i_state = I_CLEAR  |         |
       |            |                       |         V
       |            |                       |      if (inode->i_state & (I_FREEING|I_WILL_FREE))
       |            |                       |              continue;           <==== NOT MATCH
       |            |                       |
       |            |                       | (DANGER from here on! Accessing disposing inode!)
       |            |                       |
       |            |                       |      __iget()
       |            |                       |        list_move() <===== PANIC on poisoned list !!
       V            V                       |
      (time)
      =====================================================================
      Reported-by: default avatarMasayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b6fac63c
  15. 27 Mar, 2009 1 commit
    • Nick Piggin's avatar
      fs: avoid I_NEW inodes · aabb8fdb
      Nick Piggin authored
      To be on the safe side, it should be less fragile to exclude I_NEW inodes
      from inode list scans by default (unless there is an important reason to
      have them).
      
      Normally they will get excluded (eg.  by zero refcount or writecount etc),
      however it is a bit fragile for list walkers to know exactly what parts of
      the inode state is set up and valid to test when in I_NEW.  So along these
      lines, move I_NEW checks upward as well (sometimes taking I_FREEING etc
      checks with them too -- this shouldn't be a problem should it?)
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Acked-by: default avatarJan Kara <jack@suse.cz>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      aabb8fdb
  16. 29 Apr, 2008 3 commits
  17. 16 Jul, 2007 1 commit
  18. 11 Feb, 2007 1 commit
  19. 09 Jan, 2006 1 commit
    • Andrew Morton's avatar
      [PATCH] drop-pagecache · 9d0243bc
      Andrew Morton authored
      Add /proc/sys/vm/drop_caches.  When written to, this will cause the kernel to
      discard as much pagecache and/or reclaimable slab objects as it can.  THis
      operation requires root permissions.
      
      It won't drop dirty data, so the user should run `sync' first.
      
      Caveats:
      
      a) Holds inode_lock for exorbitant amounts of time.
      
      b) Needs to be taught about NUMA nodes: propagate these all the way through
         so the discarding can be controlled on a per-node basis.
      
      This is a debugging feature: useful for getting consistent results between
      filesystem benchmarks.  We could possibly put it under a config option, but
      it's less than 300 bytes.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9d0243bc