The commit is pushed to "branch-rh8-4.18.0-80.1.2.vz8.3.x-ovz" and will appear
at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-80.1.2.vz8.3.4
------>
commit 2094ac124375fb67f1e0c00ae80d742a7229e9b4
Author: Kirill Tkhai <ktk...@virtuozzo.com>
Date: Thu Apr 2 17:12:14 2020 +0300
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.
[ktk...@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 <ktk...@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov....@gmail.com>
Tested-by: Shakeel Butt <shake...@google.com>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabi...@virtuozzo.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Guenter Roeck <li...@roeck-us.net>
Cc: "Huang, Ying" <ying.hu...@intel.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Josef Bacik <jba...@fb.com>
Cc: Li RongQing <lirongq...@baidu.com>
Cc: Matthew Wilcox <wi...@infradead.org>
Cc: Matthias Kaehlcke <m...@chromium.org>
Cc: Mel Gorman <mgor...@techsingularity.net>
Cc: Michal Hocko <mho...@kernel.org>
Cc: Minchan Kim <minc...@kernel.org>
Cc: Philippe Ombredanne <pombreda...@nexb.com>
Cc: Roman Gushchin <g...@fb.com>
Cc: Sahitya Tummala <stumm...@codeaurora.org>
Cc: Stephen Rothwell <s...@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Waiman Long <long...@redhat.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
(cherry picked from commit b4c2b231c3ba155623591fb6301ed97b95e1c039)
Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com>
---
include/linux/shrinker.h | 4 +++
mm/vmscan.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 8d912bc91bf5..cec7a37e8193 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -68,6 +68,10 @@ struct shrinker {
/* These are for internal use */
struct list_head list;
+#ifdef CONFIG_MEMCG_KMEM
+ /* ID in shrinker_idr */
+ int id;
+#endif
/* objs pending delete, per node */
atomic_long_t *nr_deferred;
};
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d99fb2be1c36..d14f954ab95b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -182,6 +182,50 @@ 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 cgroup_reclaim(struct scan_control *sc)
{
@@ -281,11 +325,28 @@ 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;
}
@@ -315,6 +376,8 @@ 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);
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