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From: Muchun Song <songmuchun@bytedance.com>
To: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com,
	akpm@linux-foundation.org
Cc: cgroups@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org,
	Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH 1/4] mm: memcontrol: remove memcg check from memcg_oom_recover
Date: Sat, 13 Feb 2021 01:01:56 +0800	[thread overview]
Message-ID: <20210212170159.32153-1-songmuchun@bytedance.com> (raw)

The memcg_oom_recover() almost never do anything but the test (because
oom_disabled is a rarely used) is just waste of cycles in some hot
paths (e.g. kmem uncharge). And it is very small, so it is better to
make it inline. Also, the parameter of memcg cannot be NULL, so removing
the check can reduce useless check.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/memcontrol.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8c035846c7a4..7afca9677693 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1925,7 +1925,7 @@ static int memcg_oom_wake_function(wait_queue_entry_t *wait,
 	return autoremove_wake_function(wait, mode, sync, arg);
 }
 
-static void memcg_oom_recover(struct mem_cgroup *memcg)
+static inline void memcg_oom_recover(struct mem_cgroup *memcg)
 {
 	/*
 	 * For the following lockless ->under_oom test, the only required
@@ -1935,7 +1935,7 @@ static void memcg_oom_recover(struct mem_cgroup *memcg)
 	 * achieved by invoking mem_cgroup_mark_under_oom() before
 	 * triggering notification.
 	 */
-	if (memcg && memcg->under_oom)
+	if (memcg->under_oom)
 		__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
 }
 
-- 
2.11.0


WARNING: multiple messages have this Message-ID (diff)
From: Muchun Song <songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>
To: hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org,
	mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Muchun Song <songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>
Subject: [PATCH 1/4] mm: memcontrol: remove memcg check from memcg_oom_recover
Date: Sat, 13 Feb 2021 01:01:56 +0800	[thread overview]
Message-ID: <20210212170159.32153-1-songmuchun@bytedance.com> (raw)

The memcg_oom_recover() almost never do anything but the test (because
oom_disabled is a rarely used) is just waste of cycles in some hot
paths (e.g. kmem uncharge). And it is very small, so it is better to
make it inline. Also, the parameter of memcg cannot be NULL, so removing
the check can reduce useless check.

Signed-off-by: Muchun Song <songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>
---
 mm/memcontrol.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8c035846c7a4..7afca9677693 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1925,7 +1925,7 @@ static int memcg_oom_wake_function(wait_queue_entry_t *wait,
 	return autoremove_wake_function(wait, mode, sync, arg);
 }
 
-static void memcg_oom_recover(struct mem_cgroup *memcg)
+static inline void memcg_oom_recover(struct mem_cgroup *memcg)
 {
 	/*
 	 * For the following lockless ->under_oom test, the only required
@@ -1935,7 +1935,7 @@ static void memcg_oom_recover(struct mem_cgroup *memcg)
 	 * achieved by invoking mem_cgroup_mark_under_oom() before
 	 * triggering notification.
 	 */
-	if (memcg && memcg->under_oom)
+	if (memcg->under_oom)
 		__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
 }
 
-- 
2.11.0


             reply	other threads:[~2021-02-12 17:03 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-12 17:01 Muchun Song [this message]
2021-02-12 17:01 ` [PATCH 1/4] mm: memcontrol: remove memcg check from memcg_oom_recover Muchun Song
2021-02-12 17:01 ` [PATCH 2/4] mm: memcontrol: add missing memcg_oom_recover() when uncharge slab page Muchun Song
2021-02-12 17:01   ` Muchun Song
2021-02-15  9:37   ` Michal Hocko
2021-02-15  9:37     ` Michal Hocko
2021-02-12 17:01 ` [PATCH 3/4] mm: memcontrol: bail out early when id is zero Muchun Song
2021-02-12 17:01   ` Muchun Song
2021-02-15  9:39   ` Michal Hocko
2021-02-15  9:39     ` Michal Hocko
2021-02-15 10:09     ` [External] " Muchun Song
2021-02-15 10:09       ` Muchun Song
2021-02-15 10:09       ` Muchun Song
2021-02-15 10:27       ` Michal Hocko
2021-02-15 10:27         ` Michal Hocko
2021-02-15 11:34         ` Muchun Song
2021-02-15 11:34           ` Muchun Song
2021-02-15 11:34           ` Muchun Song
2021-02-12 17:01 ` [PATCH 4/4] mm: memcontrol: fix swap uncharge on cgroup v2 Muchun Song
2021-02-12 17:01   ` Muchun Song
2021-02-12 18:56   ` Shakeel Butt
2021-02-12 18:56     ` Shakeel Butt
2021-02-13  6:48     ` [External] " Muchun Song
2021-02-13  6:48       ` Muchun Song
2021-02-16 17:16       ` Shakeel Butt
2021-02-16 17:16         ` Shakeel Butt
2021-02-16 17:16         ` Shakeel Butt
2021-02-15  9:47   ` Michal Hocko
2021-02-15  9:47     ` Michal Hocko
2021-02-15 10:15     ` [External] " Muchun Song
2021-02-15 10:15       ` Muchun Song
2021-02-15 10:15       ` Muchun Song
2021-02-15 10:24       ` Michal Hocko
2021-02-15 10:24         ` Michal Hocko
2021-02-16 16:59   ` Johannes Weiner
2021-02-16 17:17     ` Shakeel Butt
2021-02-16 17:17       ` Shakeel Butt
2021-02-16 17:17       ` Shakeel Butt
2021-02-16 17:19     ` Michal Hocko
2021-02-16 17:19       ` Michal Hocko
2021-02-16 17:28     ` Johannes Weiner
2021-02-16 17:28       ` Johannes Weiner
2021-02-17  5:15       ` [External] " Muchun Song
2021-02-17  5:15         ` Muchun Song
2021-02-17  5:15         ` Muchun Song
2021-02-17  5:11     ` Muchun Song
2021-02-17  5:11       ` Muchun Song
2021-02-17  5:11       ` Muchun Song
2021-02-15  9:24 ` [PATCH 1/4] mm: memcontrol: remove memcg check from memcg_oom_recover Michal Hocko
2021-02-15  9:24   ` Michal Hocko

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