1. 13 Feb, 2015 27 commits
    • Vladimir Davydov's avatar
      memcg: reparent list_lrus and free kmemcg_id on css offline · 2788cf0c
      Vladimir Davydov authored
      Now, the only reason to keep kmemcg_id till css free is list_lru, which
      uses it to distribute elements between per-memcg lists.  However, it can
      be easily sorted out - we only need to change kmemcg_id of an offline
      cgroup to its parent's id, making further list_lru_add()'s add elements to
      the parent's list, and then move all elements from the offline cgroup's
      list to the one of its parent.  It will work, because a racing
      list_lru_del() does not need to know the list it is deleting the element
      from.  It can decrement the wrong nr_items counter though, but the ongoing
      reparenting will fix it.  After list_lru reparenting is done we are free
      to release kmemcg_id saving a valuable slot in a per-memcg array for new
      cgroups.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2788cf0c
    • Vladimir Davydov's avatar
      list_lru: add helpers to isolate items · 3f97b163
      Vladimir Davydov authored
      Currently, the isolate callback passed to the list_lru_walk family of
      functions is supposed to just delete an item from the list upon returning
      LRU_REMOVED or LRU_REMOVED_RETRY, while nr_items counter is fixed by
      __list_lru_walk_one after the callback returns.  Since the callback is
      allowed to drop the lock after removing an item (it has to return
      LRU_REMOVED_RETRY then), the nr_items can be less than the actual number
      of elements on the list even if we check them under the lock.  This makes
      it difficult to move items from one list_lru_one to another, which is
      required for per-memcg list_lru reparenting - we can't just splice the
      lists, we have to move entries one by one.
      
      This patch therefore introduces helpers that must be used by callback
      functions to isolate items instead of raw list_del/list_move.  These are
      list_lru_isolate and list_lru_isolate_move.  They not only remove the
      entry from the list, but also fix the nr_items counter, making sure
      nr_items always reflects the actual number of elements on the list if
      checked under the appropriate lock.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3f97b163
    • Vladimir Davydov's avatar
      memcg: free memcg_caches slot on css offline · 2a4db7eb
      Vladimir Davydov authored
      We need to look up a kmem_cache in ->memcg_params.memcg_caches arrays only
      on allocations, so there is no need to have the array entries set until
      css free - we can clear them on css offline.  This will allow us to reuse
      array entries more efficiently and avoid costly array relocations.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2a4db7eb
    • Vladimir Davydov's avatar
      slab: use css id for naming per memcg caches · f1008365
      Vladimir Davydov authored
      Currently, we use mem_cgroup->kmemcg_id to guarantee kmem_cache->name
      uniqueness.  This is correct, because kmemcg_id is only released on css
      free after destroying all per memcg caches.
      
      However, I am going to change that and release kmemcg_id on css offline,
      because it is not wise to keep it for so long, wasting valuable entries of
      memcg_cache_params->memcg_caches arrays.  Therefore, to preserve cache
      name uniqueness, let us switch to css->id.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f1008365
    • Vladimir Davydov's avatar
      cgroup: release css->id after css_free · 01e58659
      Vladimir Davydov authored
      Currently, we release css->id in css_release_work_fn, right before calling
      css_free callback, so that when css_free is called, the id may have
      already been reused for a new cgroup.
      
      I am going to use css->id to create unique names for per memcg kmem
      caches.  Since kmem caches are destroyed only on css_free, I need css->id
      to be freed after css_free was called to avoid name clashes.  This patch
      therefore moves css->id removal to css_free_work_fn.  To prevent
      css_from_id from returning a pointer to a stale css, it makes
      css_release_work_fn replace the css ptr at css_idr:css->id with NULL.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      01e58659
    • Vladimir Davydov's avatar
      slab: link memcg caches of the same kind into a list · 426589f5
      Vladimir Davydov authored
      Sometimes, we need to iterate over all memcg copies of a particular root
      kmem cache.  Currently, we use memcg_cache_params->memcg_caches array for
      that, because it contains all existing memcg caches.
      
      However, it's a bad practice to keep all caches, including those that
      belong to offline cgroups, in this array, because it will be growing
      beyond any bounds then.  I'm going to wipe away dead caches from it to
      save space.  To still be able to perform iterations over all memcg caches
      of the same kind, let us link them into a list.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      426589f5
    • Vladimir Davydov's avatar
      slab: embed memcg_cache_params to kmem_cache · f7ce3190
      Vladimir Davydov authored
      Currently, kmem_cache stores a pointer to struct memcg_cache_params
      instead of embedding it.  The rationale is to save memory when kmem
      accounting is disabled.  However, the memcg_cache_params has shrivelled
      drastically since it was first introduced:
      
      * Initially:
      
      struct memcg_cache_params {
      	bool is_root_cache;
      	union {
      		struct kmem_cache *memcg_caches[0];
      		struct {
      			struct mem_cgroup *memcg;
      			struct list_head list;
      			struct kmem_cache *root_cache;
      			bool dead;
      			atomic_t nr_pages;
      			struct work_struct destroy;
      		};
      	};
      };
      
      * Now:
      
      struct memcg_cache_params {
      	bool is_root_cache;
      	union {
      		struct {
      			struct rcu_head rcu_head;
      			struct kmem_cache *memcg_caches[0];
      		};
      		struct {
      			struct mem_cgroup *memcg;
      			struct kmem_cache *root_cache;
      		};
      	};
      };
      
      So the memory saving does not seem to be a clear win anymore.
      
      OTOH, keeping a pointer to memcg_cache_params struct instead of embedding
      it results in touching one more cache line on kmem alloc/free hot paths.
      Besides, it makes linking kmem caches in a list chained by a field of
      struct memcg_cache_params really painful due to a level of indirection,
      while I want to make them linked in the following patch.  That said, let
      us embed it.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      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: Dave Chinner <david@fromorbit.com>
      Cc: Dan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f7ce3190
    • Vladimir Davydov's avatar
      fs: shrinker: always scan at least one object of each type · 49e7e7ff
      Vladimir Davydov authored
      In super_cache_scan() we divide the number of objects of particular type
      by the total number of objects in order to distribute pressure among As a
      result, in some corner cases we can get nr_to_scan=0 even if there are
      some objects to reclaim, e.g.  dentries=1, inodes=1, fs_objects=1,
      nr_to_scan=1/3=0.
      
      This is unacceptable for per memcg kmem accounting, because this means
      that some objects may never get reclaimed after memcg death, preventing it
      from being freed.
      
      This patch therefore assures that super_cache_scan() will scan at least
      one object of each type if any.
      
      [akpm@linux-foundation.org: add comment]
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      49e7e7ff
    • Vladimir Davydov's avatar
      fs: make shrinker memcg aware · 2acb60a0
      Vladimir Davydov authored
      Now, to make any list_lru-based shrinker memcg aware we should only
      initialize its list_lru as memcg aware.  Let's do it for the general FS
      shrinker (super_block::s_shrink).
      
      There are other FS-specific shrinkers that use list_lru for storing
      objects, such as XFS and GFS2 dquot cache shrinkers, but since they
      reclaim objects that are shared among different cgroups, there is no point
      making them memcg aware.  It's a big question whether we should account
      them to memcg at all.
      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>
      2acb60a0
    • Vladimir Davydov's avatar
      list_lru: introduce per-memcg lists · 60d3fd32
      Vladimir Davydov authored
      There are several FS shrinkers, including super_block::s_shrink, that
      keep reclaimable objects in the list_lru structure.  Hence to turn them
      to memcg-aware shrinkers, it is enough to make list_lru per-memcg.
      
      This patch does the trick.  It adds an array of lru lists to the
      list_lru_node structure (per-node part of the list_lru), one for each
      kmem-active memcg, and dispatches every item addition or removal to the
      list corresponding to the memcg which the item is accounted to.  So now
      the list_lru structure is not just per node, but per node and per memcg.
      
      Not all list_lrus need this feature, so this patch also adds a new
      method, list_lru_init_memcg, which initializes a list_lru as memcg
      aware.  Otherwise (i.e.  if initialized with old list_lru_init), the
      list_lru won't have per memcg lists.
      
      Just like per memcg caches arrays, the arrays of per-memcg lists are
      indexed by memcg_cache_id, so we must grow them whenever
      memcg_nr_cache_ids is increased.  So we introduce a callback,
      memcg_update_all_list_lrus, invoked by memcg_alloc_cache_id if the id
      space is full.
      
      The locking is implemented in a manner similar to lruvecs, i.e.  we have
      one lock per node that protects all lists (both global and per cgroup) on
      the node.
      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>
      60d3fd32
    • Vladimir Davydov's avatar
      list_lru: organize all list_lrus to list · c0a5b560
      Vladimir Davydov authored
      To make list_lru memcg aware, we need all list_lrus to be kept on a list
      protected by a mutex, so that we could sleep while walking over the
      list.
      
      Therefore after this change list_lru_destroy may sleep.  Fortunately,
      there is only one user that calls it from an atomic context - it's
      put_super - and we can easily fix it by calling list_lru_destroy before
      put_super in destroy_locked_super - anyway we don't longer need lrus by
      that time.
      
      Another point that should be noted is that list_lru_destroy is allowed
      to be called on an uninitialized zeroed-out object, in which case it is
      a no-op.  Before this patch this was guaranteed by kfree, but now we
      need an explicit check there.
      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>
      c0a5b560
    • Vladimir Davydov's avatar
      list_lru: get rid of ->active_nodes · ff0b67ef
      Vladimir Davydov authored
      The active_nodes mask allows us to skip empty nodes when walking over
      list_lru items from all nodes in list_lru_count/walk.  However, these
      functions are never called from hot paths, so it doesn't seem we need
      such kind of optimization there.  OTOH, removing the mask will make it
      easier to make list_lru per-memcg.
      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>
      ff0b67ef
    • Vladimir Davydov's avatar
      memcg: add rwsem to synchronize against memcg_caches arrays relocation · 05257a1a
      Vladimir Davydov authored
      We need a stable value of memcg_nr_cache_ids in kmem_cache_create()
      (memcg_alloc_cache_params() wants it for root caches), where we only
      hold the slab_mutex and no memcg-related locks.  As a result, we have to
      update memcg_nr_cache_ids under the slab_mutex, which we can only take
      on the slab's side (see memcg_update_array_size).  This looks awkward
      and will become even worse when per-memcg list_lru is introduced, which
      also wants stable access to memcg_nr_cache_ids.
      
      To get rid of this dependency between the memcg_nr_cache_ids and the
      slab_mutex, this patch introduces a special rwsem.  The rwsem is held
      for writing during memcg_caches arrays relocation and memcg_nr_cache_ids
      updates.  Therefore one can take it for reading to get a stable access
      to memcg_caches arrays and/or memcg_nr_cache_ids.
      
      Currently the semaphore is taken for reading only from
      kmem_cache_create, right before taking the slab_mutex, so right now
      there's no much point in using rwsem instead of mutex.  However, once
      list_lru is made per-memcg it will allow list_lru initializations to
      proceed concurrently.
      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>
      05257a1a
    • Vladimir Davydov's avatar
      memcg: rename some cache id related variables · dbcf73e2
      Vladimir Davydov authored
      memcg_limited_groups_array_size, which defines the size of memcg_caches
      arrays, sounds rather cumbersome.  Also it doesn't point anyhow that
      it's related to kmem/caches stuff.  So let's rename it to
      memcg_nr_cache_ids.  It's concise and points us directly to
      memcg_cache_id.
      
      Also, rename kmem_limited_groups to memcg_cache_ida.
      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>
      dbcf73e2
    • 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
    • Vladimir Davydov's avatar
      fs: consolidate {nr,free}_cached_objects args in shrink_control · 4101b624
      Vladimir Davydov authored
      We are going to make FS shrinkers memcg-aware.  To achieve that, we will
      have to pass the memcg to scan to the nr_cached_objects and
      free_cached_objects VFS methods, which currently take only the NUMA node
      to scan.  Since the shrink_control structure already holds the node, and
      the memcg to scan will be added to it when we introduce memcg-aware
      vmscan, let us consolidate the methods' arguments in this structure to
      keep things clean.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Suggested-by: default avatarDave 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>
      4101b624
    • Vladimir Davydov's avatar
      list_lru: introduce list_lru_shrink_{count,walk} · 503c358c
      Vladimir Davydov authored
      Kmem accounting of memcg is unusable now, because it lacks slab shrinker
      support.  That means when we hit the limit we will get ENOMEM w/o any
      chance to recover.  What we should do then is to call shrink_slab, which
      would reclaim old inode/dentry caches from this cgroup.  This is what
      this patch set is intended to do.
      
      Basically, it does two things.  First, it introduces the notion of
      per-memcg slab shrinker.  A shrinker that wants to reclaim objects per
      cgroup should mark itself as SHRINKER_MEMCG_AWARE.  Then it will be
      passed the memory cgroup to scan from in shrink_control->memcg.  For
      such shrinkers shrink_slab iterates over the whole cgroup subtree under
      the target cgroup and calls the shrinker for each kmem-active memory
      cgroup.
      
      Secondly, this patch set makes the list_lru structure per-memcg.  It's
      done transparently to list_lru users - everything they have to do is to
      tell list_lru_init that they want memcg-aware list_lru.  Then the
      list_lru will automatically distribute objects among per-memcg lists
      basing on which cgroup the object is accounted to.  This way to make FS
      shrinkers (icache, dcache) memcg-aware we only need to make them use
      memcg-aware list_lru, and this is what this patch set does.
      
      As before, this patch set only enables per-memcg kmem reclaim when the
      pressure goes from memory.limit, not from memory.kmem.limit.  Handling
      memory.kmem.limit is going to be tricky due to GFP_NOFS allocations, and
      it is still unclear whether we will have this knob in the unified
      hierarchy.
      
      This patch (of 9):
      
      NUMA aware slab shrinkers use the list_lru structure to distribute
      objects coming from different NUMA nodes to different lists.  Whenever
      such a shrinker needs to count or scan objects from a particular node,
      it issues commands like this:
      
              count = list_lru_count_node(lru, sc->nid);
              freed = list_lru_walk_node(lru, sc->nid, isolate_func,
                                         isolate_arg, &sc->nr_to_scan);
      
      where sc is an instance of the shrink_control structure passed to it
      from vmscan.
      
      To simplify this, let's add special list_lru functions to be used by
      shrinkers, list_lru_shrink_count() and list_lru_shrink_walk(), which
      consolidate the nid and nr_to_scan arguments in the shrink_control
      structure.
      
      This will also allow us to avoid patching shrinkers that use list_lru
      when we make shrink_slab() per-memcg - all we will have to do is extend
      the shrink_control structure to include the target memcg and make
      list_lru_shrink_{count,walk} handle this appropriately.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Suggested-by: default avatarDave 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>
      503c358c
    • Mel Gorman's avatar
      mm: numa: avoid unnecessary TLB flushes when setting NUMA hinting entries · 10c1045f
      Mel Gorman authored
      If a PTE or PMD is already marked NUMA when scanning to mark entries for
      NUMA hinting then it is not necessary to update the entry and incur a TLB
      flush penalty.  Avoid the avoidhead where possible.
      Signed-off-by: default avatarMel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      10c1045f
    • Mel Gorman's avatar
      mm: numa: add paranoid check around pte_protnone_numa · c0e7cad9
      Mel Gorman authored
      pte_protnone_numa is only safe to use after VMA checks for PROT_NONE are
      complete.  Treating a real PROT_NONE PTE as a NUMA hinting fault is going
      to result in strangeness so add a check for it.  BUG_ON looks like
      overkill but if this is hit then it's a serious bug that could result in
      corruption so do not even try recovering.  It would have been more
      comprehensive to check VMA flags in pte_protnone_numa but it would have
      made the API ugly just for a debugging check.
      Signed-off-by: default avatarMel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c0e7cad9
    • Mel Gorman's avatar
      x86: mm: restore original pte_special check · c819f37e
      Mel Gorman authored
      Commit b38af472 ("x86,mm: fix pte_special versus pte_numa") adjusted
      the pte_special check to take into account that a special pte had
      SPECIAL and neither PRESENT nor PROTNONE.  Now that NUMA hinting PTEs
      are no longer modifying _PAGE_PRESENT it should be safe to restore the
      original pte_special behaviour.
      Signed-off-by: default avatarMel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c819f37e
    • Mel Gorman's avatar
      mm: numa: do not trap faults on the huge zero page · e944fd67
      Mel Gorman authored
      Faults on the huge zero page are pointless and there is a BUG_ON to catch
      them during fault time.  This patch reintroduces a check that avoids
      marking the zero page PAGE_NONE.
      Signed-off-by: default avatarMel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e944fd67
    • Mel Gorman's avatar
      mm: remove remaining references to NUMA hinting bits and helpers · 21d9ee3e
      Mel Gorman authored
      This patch removes the NUMA PTE bits and associated helpers.  As a
      side-effect it increases the maximum possible swap space on x86-64.
      
      One potential source of problems is races between the marking of PTEs
      PROT_NONE, NUMA hinting faults and migration.  It must be guaranteed that
      a PTE being protected is not faulted in parallel, seen as a pte_none and
      corrupting memory.  The base case is safe but transhuge has problems in
      the past due to an different migration mechanism and a dependance on page
      lock to serialise migrations and warrants a closer look.
      
      task_work hinting update			parallel fault
      ------------------------			--------------
      change_pmd_range
        change_huge_pmd
          __pmd_trans_huge_lock
            pmdp_get_and_clear
      						__handle_mm_fault
      						pmd_none
      						  do_huge_pmd_anonymous_page
      						  read? pmd_lock blocks until hinting complete, fail !pmd_none test
      						  write? __do_huge_pmd_anonymous_page acquires pmd_lock, checks pmd_none
            pmd_modify
            set_pmd_at
      
      task_work hinting update			parallel migration
      ------------------------			------------------
      change_pmd_range
        change_huge_pmd
          __pmd_trans_huge_lock
            pmdp_get_and_clear
      						__handle_mm_fault
      						  do_huge_pmd_numa_page
      						    migrate_misplaced_transhuge_page
      						    pmd_lock waits for updates to complete, recheck pmd_same
            pmd_modify
            set_pmd_at
      
      Both of those are safe and the case where a transhuge page is inserted
      during a protection update is unchanged.  The case where two processes try
      migrating at the same time is unchanged by this series so should still be
      ok.  I could not find a case where we are accidentally depending on the
      PTE not being cleared and flushed.  If one is missed, it'll manifest as
      corruption problems that start triggering shortly after this series is
      merged and only happen when NUMA balancing is enabled.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
      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: Mark Brown <broonie@kernel.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      21d9ee3e
    • Mel Gorman's avatar
      mm: convert p[te|md]_mknonnuma and remaining page table manipulations · 4d942466
      Mel Gorman authored
      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: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Acked-by: default avatarAneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Tested-by: default avatarSasha 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4d942466
    • Mel Gorman's avatar
      ppc64: add paranoid warnings for unexpected DSISR_PROTFAULT · 842915f5
      Mel Gorman authored
      ppc64 should not be depending on DSISR_PROTFAULT and it's unexpected if
      they are triggered.  This patch adds warnings just in case they are being
      accidentally depended upon.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Tested-by: default avatarSasha 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: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Rik van Riel <riel@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      842915f5
    • Mel Gorman's avatar
      mm: convert p[te|md]_numa users to p[te|md]_protnone_numa · 8a0516ed
      Mel Gorman authored
      Convert existing users of pte_numa and friends to the new helper.  Note
      that the kernel is broken after this patch is applied until the other page
      table modifiers are also altered.  This patch layout is to make review
      easier.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Acked-by: default avatarAneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
      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>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8a0516ed
    • Mel Gorman's avatar
      mm: add p[te|md] protnone helpers for use by NUMA balancing · e7bb4b6d
      Mel Gorman authored
      This is a preparatory patch that introduces protnone helpers for automatic
      NUMA balancing.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Acked-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Tested-by: default avatarSasha 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e7bb4b6d
    • Mel Gorman's avatar
      mm: numa: do not dereference pmd outside of the lock during NUMA hinting fault · 5d833062
      Mel Gorman authored
      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: default avatarMel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5d833062
  2. 12 Feb, 2015 13 commits
    • Linus Torvalds's avatar
      Merge tag 'jfs-3.20' of git://github.com/kleikamp/linux-shaggy · 87c9172f
      Linus Torvalds authored
      Pull jfs updates from David Kleikamp:
       "A couple cleanups for jfs"
      
      * tag 'jfs-3.20' of git://github.com/kleikamp/linux-shaggy:
        jfs: Deletion of an unnecessary check before the function call "unload_nls"
        jfs: get rid of homegrown endianness helpers
      87c9172f
    • Linus Torvalds's avatar
      Merge branch 'for-3.20' of git://linux-nfs.org/~bfields/linux · 61845143
      Linus Torvalds authored
      Pull nfsd updates from Bruce Fields:
       "The main change is the pNFS block server support from Christoph, which
        allows an NFS client connected to shared disk to do block IO to the
        shared disk in place of NFS reads and writes.  This also requires xfs
        patches, which should arrive soon through the xfs tree, barring
        unexpected problems.  Support for other filesystems is also possible
        if there's interest.
      
        Thanks also to Chuck Lever for continuing work to get NFS/RDMA into
        shape"
      
      * 'for-3.20' of git://linux-nfs.org/~bfields/linux: (32 commits)
        nfsd: default NFSv4.2 to on
        nfsd: pNFS block layout driver
        exportfs: add methods for block layout exports
        nfsd: add trace events
        nfsd: update documentation for pNFS support
        nfsd: implement pNFS layout recalls
        nfsd: implement pNFS operations
        nfsd: make find_any_file available outside nfs4state.c
        nfsd: make find/get/put file available outside nfs4state.c
        nfsd: make lookup/alloc/unhash_stid available outside nfs4state.c
        nfsd: add fh_fsid_match helper
        nfsd: move nfsd_fh_match to nfsfh.h
        fs: add FL_LAYOUT lease type
        fs: track fl_owner for leases
        nfs: add LAYOUT_TYPE_MAX enum value
        nfsd: factor out a helper to decode nfstime4 values
        sunrpc/lockd: fix references to the BKL
        nfsd: fix year-2038 nfs4 state problem
        svcrdma: Handle additional inline content
        svcrdma: Move read list XDR round-up logic
        ...
      61845143
    • Linus Torvalds's avatar
      Merge tag 'iommu-updates-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu · a26be149
      Linus Torvalds authored
      Pull IOMMU updates from Joerg Roedel:
       "This time with:
      
         - Generic page-table framework for ARM IOMMUs using the LPAE
           page-table format, ARM-SMMU and Renesas IPMMU make use of it
           already.
      
         - Break out the IO virtual address allocator from the Intel IOMMU so
           that it can be used by other DMA-API implementations too.  The
           first user will be the ARM64 common DMA-API implementation for
           IOMMUs
      
         - Device tree support for Renesas IPMMU
      
         - Various fixes and cleanups all over the place"
      
      * tag 'iommu-updates-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (36 commits)
        iommu/amd: Convert non-returned local variable to boolean when relevant
        iommu: Update my email address
        iommu/amd: Use wait_event in put_pasid_state_wait
        iommu/amd: Fix amd_iommu_free_device()
        iommu/arm-smmu: Avoid build warning
        iommu/fsl: Various cleanups
        iommu/fsl: Use %pa to print phys_addr_t
        iommu/omap: Print phys_addr_t using %pa
        iommu: Make more drivers depend on COMPILE_TEST
        iommu/ipmmu-vmsa: Fix IOMMU lookup when multiple IOMMUs are registered
        iommu: Disable on !MMU builds
        iommu/fsl: Remove unused fsl_of_pamu_ids[]
        iommu/fsl: Fix section mismatch
        iommu/ipmmu-vmsa: Use the ARM LPAE page table allocator
        iommu: Fix trace_map() to report original iova and original size
        iommu/arm-smmu: add support for iova_to_phys through ATS1PR
        iopoll: Introduce memory-mapped IO polling macros
        iommu/arm-smmu: don't touch the secure STLBIALL register
        iommu/arm-smmu: make use of generic LPAE allocator
        iommu: io-pgtable-arm: add non-secure quirk
        ...
      a26be149
    • Linus Torvalds's avatar
      Merge tag 'devicetree-for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux · cdd30545
      Linus Torvalds authored
      Pull DeviceTree changes from Rob Herring:
      
       - DT unittests for I2C probing and overlays from Pantelis Antoniou
      
       - Remove DT unittest dependency on OF_DYNAMIC from Gaurav Minocha
      
       - Add Tegra compatible strings missing for newer parts from Paul
         Walmsley
      
       - Various vendor prefix additions
      
      * tag 'devicetree-for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
        of: Add vendor prefix for OmniVision Technologies
        of: Use ovti for Omnivision
        of: Add vendor prefix for Truly Semiconductors Limited
        of: Add vendor prefix for Himax Technologies Inc.
        of/fdt: fix sparse warning
        of: unitest: Add I2C overlay unit tests.
        Documentation: DT: document compatible string existence requirement
        Documentation: DT bindings: add nvidia, tegra132-denver compatible string
        Documentation: DT bindings: add more Tegra chip compatible strings
        of: EXPORT_SYMBOL_GPL of_property_read_u64_array
        of: Fix brace position for struct of_device_id definition
        of/unittest: Remove obsolete code
        dt-bindings: use isil prefix for Intersil in vendor-prefixes.txt
        Add AD Holdings Plc. to vendor-prefixes.
        dt-bindings: Add Silicon Mitus vendor prefix
        Removes OF_UNITTEST dependency on OF_DYNAMIC config symbol
        pinctrl: fix up device tree bindings
        DT: Vendors: Add Everspin
        doc: add bindings document for altera fpga manager
        drivers: of: Export of_reserved_mem_device_{init,release}
      cdd30545
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm · 42cf0f20
      Linus Torvalds authored
      Pull ARM updates from Russell King:
      
       - clang assembly fixes from Ard
      
       - optimisations and cleanups for Aurora L2 cache support
      
       - efficient L2 cache support for secure monitor API on Exynos SoCs
      
       - debug menu cleanup from Daniel Thompson to allow better behaviour for
         multiplatform kernels
      
       - StrongARM SA11x0 conversion to irq domains, and pxa_timer
      
       - kprobes updates for older ARM CPUs
      
       - move probes support out of arch/arm/kernel to arch/arm/probes
      
       - add inline asm support for the rbit (reverse bits) instruction
      
       - provide an ARM mode secondary CPU entry point (for Qualcomm CPUs)
      
       - remove the unused ARMv3 user access code
      
       - add driver_override support to AMBA Primecell bus
      
      * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (55 commits)
        ARM: 8256/1: driver coamba: add device binding path 'driver_override'
        ARM: 8301/1: qcom: Use secondary_startup_arm()
        ARM: 8302/1: Add a secondary_startup that assumes ARM mode
        ARM: 8300/1: teach __asmeq that r11 == fp and r12 == ip
        ARM: kprobes: Fix compilation error caused by superfluous '*'
        ARM: 8297/1: cache-l2x0: optimize aurora range operations
        ARM: 8296/1: cache-l2x0: clean up aurora cache handling
        ARM: 8284/1: sa1100: clear RCSR_SMR on resume
        ARM: 8283/1: sa1100: collie: clear PWER register on machine init
        ARM: 8282/1: sa1100: use handle_domain_irq
        ARM: 8281/1: sa1100: move GPIO-related IRQ code to gpio driver
        ARM: 8280/1: sa1100: switch to irq_domain_add_simple()
        ARM: 8279/1: sa1100: merge both GPIO irqdomains
        ARM: 8278/1: sa1100: split irq handling for low GPIOs
        ARM: 8291/1: replace magic number with PAGE_SHIFT macro in fixup_pv code
        ARM: 8290/1: decompressor: fix a wrong comment
        ARM: 8286/1: mm: Fix dma_contiguous_reserve comment
        ARM: 8248/1: pm: remove outdated comment
        ARM: 8274/1: Fix DEBUG_LL for multi-platform kernels (without PL01X)
        ARM: 8273/1: Seperate DEBUG_UART_PHYS from DEBUG_LL on EP93XX
        ...
      42cf0f20
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32 · a2f0bb03
      Linus Torvalds authored
      Pull AVR32 update from Hans-Christian Egtvedt.
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32:
        avr32: update all default configurations
        avr32: remove fake at91 cpu identification
        avr32: wire up missing syscalls
      a2f0bb03
    • Linus Torvalds's avatar
      Merge tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 41cbc01f
      Linus Torvalds authored
      Pull tracing updates from Steven Rostedt:
       "The updates included in this pull request for ftrace are:
      
         o Several clean ups to the code
      
           One such clean up was to convert to 64 bit time keeping, in the
           ring buffer benchmark code.
      
         o Adding of __print_array() helper macro for TRACE_EVENT()
      
         o Updating the sample/trace_events/ to add samples of different ways
           to make trace events.  Lots of features have been added since the
           sample code was made, and these features are mostly unknown.
           Developers have been making their own hacks to do things that are
           already available.
      
         o Performance improvements.  Most notably, I found a performance bug
           where a waiter that is waiting for a full page from the ring buffer
           will see that a full page is not available, and go to sleep.  The
           sched event caused by it going to sleep would cause it to wake up
           again.  It would see that there was still not a full page, and go
           back to sleep again, and that would wake it up again, until finally
           it would see a full page.  This change has been marked for stable.
      
        Other improvements include removing global locks from fast paths"
      
      * tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
        ring-buffer: Do not wake up a splice waiter when page is not full
        tracing: Fix unmapping loop in tracing_mark_write
        tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()
        tracing: Add TRACE_EVENT_FN example
        tracing: Add TRACE_EVENT_CONDITION sample
        tracing: Update the TRACE_EVENT fields available in the sample code
        tracing: Separate out initializing top level dir from instances
        tracing: Make tracing_init_dentry_tr() static
        trace: Use 64-bit timekeeping
        tracing: Add array printing helper
        tracing: Remove newline from trace_printk warning banner
        tracing: Use IS_ERR() check for return value of tracing_init_dentry()
        tracing: Remove unneeded includes of debugfs.h and fs.h
        tracing: Remove taking of trace_types_lock in pipe files
        tracing: Add ref count to tracer for when they are being read by pipe
      41cbc01f
    • Linus Torvalds's avatar
      Merge tag 'ktest-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest · 12df4289
      Linus Torvalds authored
      Pull ktest updates from Steven Rostedt:
       "The following ktest updates were done:
      
         o Added timings to various parts of the test (build, install, boot,
           tests) and report them so that the users can keep track of changes.
      
         o Josh Poimboeuf fixed the console output to work better with virtual
           machine targets.
      
         o Various clean ups and fixes"
      
      * tag 'ktest-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
        ktest: Place quotes around item variable
        ktest: Cleanup terminal on dodie() failure
        ktest: Print build,install,boot,test times at success and failure
        ktest: Enable user input to the console
        ktest: Give console process a dedicated tty
        ktest: Rename start_monitor_and_boot to start_monitor_and_install
        ktest: Show times for build, install, boot and test
        ktest: Restore tty settings after closing console
        ktest: Add timings for commands
      12df4289
    • Linus Torvalds's avatar
      Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security · 8cc748aa
      Linus Torvalds authored
      Pull security layer updates from James Morris:
       "Highlights:
      
         - Smack adds secmark support for Netfilter
         - /proc/keys is now mandatory if CONFIG_KEYS=y
         - TPM gets its own device class
         - Added TPM 2.0 support
         - Smack file hook rework (all Smack users should review this!)"
      
      * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (64 commits)
        cipso: don't use IPCB() to locate the CIPSO IP option
        SELinux: fix error code in policydb_init()
        selinux: add security in-core xattr support for pstore and debugfs
        selinux: quiet the filesystem labeling behavior message
        selinux: Remove unused function avc_sidcmp()
        ima: /proc/keys is now mandatory
        Smack: Repair netfilter dependency
        X.509: silence asn1 compiler debug output
        X.509: shut up about included cert for silent build
        KEYS: Make /proc/keys unconditional if CONFIG_KEYS=y
        MAINTAINERS: email update
        tpm/tpm_tis: Add missing ifdef CONFIG_ACPI for pnp_acpi_device
        smack: fix possible use after frees in task_security() callers
        smack: Add missing logging in bidirectional UDS connect check
        Smack: secmark support for netfilter
        Smack: Rework file hooks
        tpm: fix format string error in tpm-chip.c
        char/tpm/tpm_crb: fix build error
        smack: Fix a bidirectional UDS connect check typo
        smack: introduce a special case for tmpfs in smack_d_instantiate()
        ...
      8cc748aa
    • Linus Torvalds's avatar
      Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit · 7184487f
      Linus Torvalds authored
      Pull audit fix from Paul Moore:
       "Just one patch from the audit tree for v3.20, and a very minor one at
        that.
      
        The patch simply removes an old, unused field from the audit_krule
        structure, a private audit-only struct.  In audit related news, we did
        a proper overhaul of the audit pathname code and removed the nasty
        getname()/putname() hacks for audit, you should see those patches in
        Al's vfs tree if you haven't already.
      
        That's it for audit this time, let's hope for a quiet -rcX series"
      
      * 'upstream' of git://git.infradead.org/users/pcmoore/audit:
        audit: remove vestiges of vers_ops
      7184487f
    • Rob Herring's avatar
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 59d53737
      Linus Torvalds authored
      Merge second set of updates from Andrew Morton:
       "More of MM"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits)
        mm/nommu.c: fix arithmetic overflow in __vm_enough_memory()
        mm/mmap.c: fix arithmetic overflow in __vm_enough_memory()
        vmstat: Reduce time interval to stat update on idle cpu
        mm/page_owner.c: remove unnecessary stack_trace field
        Documentation/filesystems/proc.txt: describe /proc/<pid>/map_files
        mm: incorporate read-only pages into transparent huge pages
        vmstat: do not use deferrable delayed work for vmstat_update
        mm: more aggressive page stealing for UNMOVABLE allocations
        mm: always steal split buddies in fallback allocations
        mm: when stealing freepages, also take pages created by splitting buddy page
        mincore: apply page table walker on do_mincore()
        mm: /proc/pid/clear_refs: avoid split_huge_page()
        mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
        mempolicy: apply page table walker on queue_pages_range()
        arch/powerpc/mm/subpage-prot.c: use walk->vma and walk_page_vma()
        memcg: cleanup preparation for page table walk
        numa_maps: remove numa_maps->vma
        numa_maps: fix typo in gather_hugetbl_stats
        pagemap: use walk->vma instead of calling find_vma()
        clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()
        ...
      59d53737
    • Linus Torvalds's avatar
      Merge tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux · d3f180ea
      Linus Torvalds authored
      Pull powerpc updates from Michael Ellerman:
      
       - Update of all defconfigs
      
       - Addition of a bunch of config options to modernise our defconfigs
      
       - Some PS3 updates from Geoff
      
       - Optimised memcmp for 64 bit from Anton
      
       - Fix for kprobes that allows 'perf probe' to work from Naveen
      
       - Several cxl updates from Ian & Ryan
      
       - Expanded support for the '24x7' PMU from Cody & Sukadev
      
       - Freescale updates from Scott:
          "Highlights include 8xx optimizations, some more work on datapath
           device tree content, e300 machine check support, t1040 corenet
           error reporting, and various cleanups and fixes"
      
      * tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (102 commits)
        cxl: Add missing return statement after handling AFU errror
        cxl: Fail AFU initialisation if an invalid configuration record is found
        cxl: Export optional AFU configuration record in sysfs
        powerpc/mm: Warn on flushing tlb page in kernel context
        powerpc/powernv: Add OPAL soft-poweroff routine
        powerpc/perf/hv-24x7: Document sysfs event description entries
        powerpc/perf/hv-gpci: add the remaining gpci requests
        powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated
        powerpc/perf/hv-24x7: parse catalog and populate sysfs with events
        perf: define EVENT_DEFINE_RANGE_FORMAT_LITE helper
        perf: add PMU_EVENT_ATTR_STRING() helper
        perf: provide sysfs_show for struct perf_pmu_events_attr
        powerpc/kernel: Avoid initializing device-tree pointer twice
        powerpc: Remove old compile time disabled syscall tracing code
        powerpc/kernel: Make syscall_exit a local label
        cxl: Fix device_node reference counting
        powerpc/mm: bail out early when flushing TLB page
        powerpc: defconfigs: add MTD_SPI_NOR (new dependency for M25P80)
        perf/powerpc: reset event hw state when adding it to the PMU
        powerpc/qe: Use strlcpy()
        ...
      d3f180ea