From: Chris Down <chris@chrisdown.name>
To: Vasily Averin <vvs@virtuozzo.com>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Michal Hocko <mhocko@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, kernel@openvz.org,
Mel Gorman <mgorman@techsingularity.net>,
Uladzislau Rezki <urezki@gmail.com>
Subject: Re: [PATCH memcg] mm/page_alloc.c: avoid statistic update with 0
Date: Tue, 12 Oct 2021 13:02:01 +0100 [thread overview]
Message-ID: <YWV5OY5I0MhTtsn1@chrisdown.name> (raw)
In-Reply-To: <f52c5cd3-9b74-0fd5-2b7b-83ca21c52b2a@virtuozzo.com>
Vasily Averin writes:
>Yes, it's not a bug, it just makes the kernel a bit more efficient in a very unlikely case.
>However, it looks strange and makes uninformed code reviewers like me worry about possible
>problems inside the affected functions. No one else calls these functions from 0.
This statement is meaningless without data. If you have proof that it makes the
kernel more efficient, then please provide the profiles.
As it is I'd be surprised if this improved things. Either the code is hot
enough that the additional branch is cumbersome, or it's cold enough that it
doesn't even matter.
prev parent reply other threads:[~2021-10-12 12:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-08 9:24 Vasily Averin
2021-10-08 11:47 ` Vlastimil Babka
2021-10-12 10:42 ` Vasily Averin
2021-10-12 11:09 ` David Hildenbrand
2021-10-12 11:38 ` Mel Gorman
2021-10-12 12:02 ` Chris Down [this message]
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