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From: Wei Yang <richard.weiyang@gmail.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,
	Wei Yang <richard.weiyang@gmail.com>
Subject: [Patch v2 1/3] mm/memcg: set memcg after css verified and got reference
Date: Wed, 30 Mar 2022 23:47:17 +0000	[thread overview]
Message-ID: <20220330234719.18340-2-richard.weiyang@gmail.com> (raw)
In-Reply-To: <20220330234719.18340-1-richard.weiyang@gmail.com>

Instead of reset memcg when css is either not verified or not got
reference, we can set it after these process.

No functional change, just simplified the code a little.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 mm/memcontrol.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index dc193e83794d..eed9916cdce5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1057,15 +1057,10 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 		 * is provided by the caller, so we know it's alive
 		 * and kicking, and don't take an extra reference.
 		 */
-		memcg = mem_cgroup_from_css(css);
-
-		if (css == &root->css)
-			break;
-
-		if (css_tryget(css))
+		if (css == &root->css || css_tryget(css)) {
+			memcg = mem_cgroup_from_css(css);
 			break;
-
-		memcg = NULL;
+		}
 	}
 
 	if (reclaim) {
-- 
2.33.1



WARNING: multiple messages have this Message-ID (diff)
From: Wei Yang <richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@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,
	Wei Yang
	<richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: [Patch v2 1/3] mm/memcg: set memcg after css verified and got reference
Date: Wed, 30 Mar 2022 23:47:17 +0000	[thread overview]
Message-ID: <20220330234719.18340-2-richard.weiyang@gmail.com> (raw)
In-Reply-To: <20220330234719.18340-1-richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Instead of reset memcg when css is either not verified or not got
reference, we can set it after these process.

No functional change, just simplified the code a little.

Signed-off-by: Wei Yang <richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Acked-by: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
---
 mm/memcontrol.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index dc193e83794d..eed9916cdce5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1057,15 +1057,10 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 		 * is provided by the caller, so we know it's alive
 		 * and kicking, and don't take an extra reference.
 		 */
-		memcg = mem_cgroup_from_css(css);
-
-		if (css == &root->css)
-			break;
-
-		if (css_tryget(css))
+		if (css == &root->css || css_tryget(css)) {
+			memcg = mem_cgroup_from_css(css);
 			break;
-
-		memcg = NULL;
+		}
 	}
 
 	if (reclaim) {
-- 
2.33.1


  reply	other threads:[~2022-03-30 23:47 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-30 23:47 [Patch v2 0/3] mm/memcg: some cleanup for mem_cgroup_iter() Wei Yang
2022-03-30 23:47 ` Wei Yang
2022-03-30 23:47 ` Wei Yang [this message]
2022-03-30 23:47   ` [Patch v2 1/3] mm/memcg: set memcg after css verified and got reference Wei Yang
2022-03-31  0:20   ` Roman Gushchin
2022-03-31  0:20     ` Roman Gushchin
2022-03-30 23:47 ` [Patch v2 2/3] mm/memcg: set pos explicitly for reclaim and !reclaim Wei Yang
2022-03-30 23:47   ` Wei Yang
2022-03-31  0:21   ` Roman Gushchin
2022-03-31  0:21     ` Roman Gushchin
2022-03-31 15:03   ` Johannes Weiner
2022-03-31 15:03     ` Johannes Weiner
2022-03-30 23:47 ` [Patch v2 3/3] mm/memcg: move generation assignment and comparison together Wei Yang
2022-03-30 23:47   ` Wei Yang
2022-03-31  0:28   ` Roman Gushchin
2022-03-31  0:28     ` Roman Gushchin

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