From: Michal Hocko <mhocko@kernel.org>
To: Chris Down <chris@chrisdown.name>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>, Tejun Heo <tj@kernel.org>,
Roman Gushchin <guro@fb.com>, Dennis Zhou <dennis@kernel.org>,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
linux-mm@kvack.org, kernel-team@fb.com
Subject: Re: [PATCH REBASED] mm, memcg: Make scan aggression always exclude protection
Date: Thu, 30 May 2019 08:51:11 +0200 [thread overview]
Message-ID: <20190530065111.GC6703@dhcp22.suse.cz> (raw)
In-Reply-To: <20190530064453.GA110128@chrisdown.name>
On Wed 29-05-19 23:44:53, Chris Down wrote:
> Michal Hocko writes:
> > Maybe I am missing something so correct me if I am wrong but the new
> > calculation actually means that we always allow to scan even min
> > protected memcgs right?
>
> We check if the memcg is min protected as a precondition for coming into
> this function at all, so this generally isn't possible. See the
> mem_cgroup_protected MEMCG_PROT_MIN check in shrink_node.
OK, that is the part I was missing, I got confused by checking the min
limit as well here. Thanks for the clarification. A comment would be
handy or do we really need to consider min at all?
> (Of course, it's possible we race with going within protection thresholds
> again, but this patch doesn't make that any better or worse than the
> previous situation.)
Yeah.
With the above clarified. The code the resulting code is much easier to
follow and the overal logic makes sense to me.
Acked-by: Michal Hocko <mhocko@suse.com>
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-05-30 6:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-28 21:30 [PATCH] mm, memcg: Make scan aggression always exclude protection Chris Down
2019-03-01 0:03 ` Roman Gushchin
2019-03-22 16:03 ` [PATCH REBASED] " Chris Down
2019-03-22 20:10 ` Andrew Morton
2019-03-22 22:00 ` Chris Down
2019-03-22 22:29 ` Roman Gushchin
2019-03-22 22:49 ` Roman Gushchin
2019-03-22 22:51 ` Chris Down
2019-03-22 22:49 ` Chris Down
2019-03-22 23:01 ` Roman Gushchin
2019-03-22 23:51 ` Chris Down
2019-05-30 6:12 ` Michal Hocko
2019-05-30 6:44 ` Chris Down
2019-05-30 6:51 ` Michal Hocko [this message]
2019-05-30 20:52 ` Chris Down
2019-05-31 6:28 ` Michal Hocko
2019-05-31 19:27 ` Chris Down
2019-07-16 17:10 ` Johannes Weiner
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