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authorKirill Tkhai <ktkhai@virtuozzo.com>2018-08-17 15:47:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-17 16:20:30 -0700
commitb4c2b231c3ba155623591fb6301ed97b95e1c039 (patch)
tree531384204bd56bc90a2e1136065576f100b50672 /mm
parent84c07d11aa619c6d24c682f469b10f344f0c02aa (diff)
downloadlinux-stericsson-b4c2b231c3ba155623591fb6301ed97b95e1c039.tar.gz
mm: assign id to every memcg-aware shrinker
Introduce shrinker::id number, which is used to enumerate memcg-aware shrinkers. The number start from 0, and the code tries to maintain it as small as possible. This will be used to represent a memcg-aware shrinkers in memcg shrinkers map. Since all memcg-aware shrinkers are based on list_lru, which is per-memcg in case of !CONFIG_MEMCG_KMEM only, the new functionality will be under this config option. [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112546435.4097.10607140323811756557.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063054586.1818.6041047871606697364.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Tested-by: Shakeel Butt <shakeelb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <jbacik@fb.com> Cc: Li RongQing <lirongqing@baidu.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Roman Gushchin <guro@fb.com> Cc: Sahitya Tummala <stummala@codeaurora.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmscan.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index a00d94530e57..5cb4f779ea4a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -169,6 +169,50 @@ unsigned long vm_total_pages;
static LIST_HEAD(shrinker_list);
static DECLARE_RWSEM(shrinker_rwsem);
+#ifdef CONFIG_MEMCG_KMEM
+static DEFINE_IDR(shrinker_idr);
+static int shrinker_nr_max;
+
+static int prealloc_memcg_shrinker(struct shrinker *shrinker)
+{
+ int id, ret = -ENOMEM;
+
+ down_write(&shrinker_rwsem);
+ /* This may call shrinker, so it must use down_read_trylock() */
+ id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL);
+ if (id < 0)
+ goto unlock;
+
+ if (id >= shrinker_nr_max)
+ shrinker_nr_max = id + 1;
+ shrinker->id = id;
+ ret = 0;
+unlock:
+ up_write(&shrinker_rwsem);
+ return ret;
+}
+
+static void unregister_memcg_shrinker(struct shrinker *shrinker)
+{
+ int id = shrinker->id;
+
+ BUG_ON(id < 0);
+
+ down_write(&shrinker_rwsem);
+ idr_remove(&shrinker_idr, id);
+ up_write(&shrinker_rwsem);
+}
+#else /* CONFIG_MEMCG_KMEM */
+static int prealloc_memcg_shrinker(struct shrinker *shrinker)
+{
+ return 0;
+}
+
+static void unregister_memcg_shrinker(struct shrinker *shrinker)
+{
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
#ifdef CONFIG_MEMCG
static bool global_reclaim(struct scan_control *sc)
{
@@ -313,11 +357,28 @@ int prealloc_shrinker(struct shrinker *shrinker)
shrinker->nr_deferred = kzalloc(size, GFP_KERNEL);
if (!shrinker->nr_deferred)
return -ENOMEM;
+
+ if (shrinker->flags & SHRINKER_MEMCG_AWARE) {
+ if (prealloc_memcg_shrinker(shrinker))
+ goto free_deferred;
+ }
+
return 0;
+
+free_deferred:
+ kfree(shrinker->nr_deferred);
+ shrinker->nr_deferred = NULL;
+ return -ENOMEM;
}
void free_prealloced_shrinker(struct shrinker *shrinker)
{
+ if (!shrinker->nr_deferred)
+ return;
+
+ if (shrinker->flags & SHRINKER_MEMCG_AWARE)
+ unregister_memcg_shrinker(shrinker);
+
kfree(shrinker->nr_deferred);
shrinker->nr_deferred = NULL;
}
@@ -347,6 +408,8 @@ void unregister_shrinker(struct shrinker *shrinker)
{
if (!shrinker->nr_deferred)
return;
+ if (shrinker->flags & SHRINKER_MEMCG_AWARE)
+ unregister_memcg_shrinker(shrinker);
down_write(&shrinker_rwsem);
list_del(&shrinker->list);
up_write(&shrinker_rwsem);