[Devel] [PATCH RHEL7 COMMIT] ms/mm: assign id to every memcg-aware shrinker
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Sep 5 12:37:09 MSK 2018
The commit is pushed to "branch-rh7-3.10.0-862.11.6.vz7.71.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-862.11.6.vz7.71.8
------>
commit 97b77b03f78043cd7fd95f36757c9046db9f50c3
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date: Wed Sep 5 12:37:08 2018 +0300
ms/mm: assign id to every memcg-aware shrinker
ms commit b4c2b231c3ba
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 at 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 at virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev at gmail.com>
Tested-by: Shakeel Butt <shakeelb at google.com>
Cc: Al Viro <viro at zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin at virtuozzo.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Guenter Roeck <linux at roeck-us.net>
Cc: "Huang, Ying" <ying.huang at intel.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Josef Bacik <jbacik at fb.com>
Cc: Li RongQing <lirongqing at baidu.com>
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Matthias Kaehlcke <mka at chromium.org>
Cc: Mel Gorman <mgorman at techsingularity.net>
Cc: Michal Hocko <mhocko at kernel.org>
Cc: Minchan Kim <minchan at kernel.org>
Cc: Philippe Ombredanne <pombredanne at nexb.com>
Cc: Roman Gushchin <guro at fb.com>
Cc: Sahitya Tummala <stummala at codeaurora.org>
Cc: Stephen Rothwell <sfr at canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Waiman Long <longman at redhat.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
=====================
Patchset description:
Port "Improve shrink_slab() scalability" patchset
https://jira.sw.ru/browse/PSBM-88027
This is backport of the patchset improving the performance
of overcommited containers with many memcgs and mounts.
The original set is in Linus' tree, and came into 4.19-rc1.
Kirill Tkhai (12):
mm: assign id to every memcg-aware shrinker
mm/memcontrol.c: move up for_each_mem_cgroup{, _tree} defines
mm, memcg: assign memcg-aware shrinkers bitmap to memcg
fs: propagate shrinker::id to list_lru
mm/list_lru.c: add memcg argument to list_lru_from_kmem()
mm/list_lru: pass dst_memcg argument to memcg_drain_list_lru_node()
mm/list_lru.c: pass lru argument to memcg_drain_list_lru_node()
mm/list_lru.c: set bit in memcg shrinker bitmap on first list_lru item appearance
mm/memcontrol.c: export mem_cgroup_is_root()
mm/vmscan.c: iterate only over charged shrinkers during memcg shrink_slab()
mm: add SHRINK_EMPTY shrinker methods return value
mm/vmscan.c: clear shrinker bit if there are no objects related to memcg
Vladimir Davydov (1):
mm/vmscan.c: generalize shrink_slab() calls in shrink_node()
---
include/linux/shrinker.h | 5 +++-
mm/vmscan.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 5e706a524592..a8bbeaa3c66e 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -53,7 +53,10 @@ struct shrinker {
struct shrink_control *sc);
unsigned long (*scan_objects)(struct shrinker *,
struct shrink_control *sc);
-
+#ifdef CONFIG_MEMCG_KMEM
+ /* ID in shrinker_idr */
+ int id;
+#endif
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
unsigned long flags;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index aefa4bc33062..418154200a76 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -157,6 +157,49 @@ unsigned long vm_total_pages; /* The total number of pages which the VM controls
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 register_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 register_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)
{
@@ -249,10 +292,20 @@ int register_shrinker(struct shrinker *shrinker)
if (!shrinker->nr_deferred)
return -ENOMEM;
+ if (shrinker->flags & SHRINKER_MEMCG_AWARE) {
+ if (register_memcg_shrinker(shrinker))
+ goto free_deferred;
+ }
+
down_write(&shrinker_rwsem);
list_add_tail(&shrinker->list, &shrinker_list);
up_write(&shrinker_rwsem);
return 0;
+
+free_deferred:
+ kfree(shrinker->nr_deferred);
+ shrinker->nr_deferred = NULL;
+ return -ENOMEM;
}
EXPORT_SYMBOL(register_shrinker);
@@ -261,10 +314,17 @@ EXPORT_SYMBOL(register_shrinker);
*/
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);
kfree(shrinker->nr_deferred);
+ shrinker->nr_deferred = NULL;
}
EXPORT_SYMBOL(unregister_shrinker);
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