From: Shakeel Butt <shakeelb@google.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Tejun Heo <tj@kernel.org>, Roman Gushchin <guro@fb.com>,
Michal Hocko <mhocko@suse.com>, Linux MM <linux-mm@kvack.org>,
Cgroups <cgroups@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Kernel Team <kernel-team@fb.com>
Subject: Re: [PATCH] mm: memcontrol: prevent starvation when writing memory.high
Date: Tue, 12 Jan 2021 12:28:04 -0800 [thread overview]
Message-ID: <CALvZod4qKrwvT7MAKrhemjrBfAAsk=fKa9g8QRij42j0CaF4nw@mail.gmail.com> (raw)
In-Reply-To: <X/3+IgDVb+Jn4XfQ@cmpxchg.org>
On Tue, Jan 12, 2021 at 11:55 AM Johannes Weiner <hannes@cmpxchg.org> wrote:
>
> On Tue, Jan 12, 2021 at 10:59:58AM -0800, Shakeel Butt wrote:
> > On Tue, Jan 12, 2021 at 9:12 AM Johannes Weiner <hannes@cmpxchg.org> wrote:
> > >
> > > When a value is written to a cgroup's memory.high control file, the
> > > write() context first tries to reclaim the cgroup to size before
> > > putting the limit in place for the workload. Concurrent charges from
> > > the workload can keep such a write() looping in reclaim indefinitely.
> > >
> >
> > Is this observed on real workload?
>
> Yes.
>
> On several production hosts running a particularly aggressive
> workload, we've observed writers to memory.high getting stuck for
> minutes while consuming significant amount of CPU.
>
Good to add this in the commit message or at least mentioning that it
happened in production.
> > Any particular reason to remove !reclaimed?
>
> It's purpose so far was to allow successful reclaim to continue
> indefinitely, while restricting no-progress loops to 'nr_retries'.
>
> Without the first part, it doesn't really matter whether reclaim is
> making progress or not: we do a maximum of 'nr_retries' loops until
> the cgroup size meets the new limit, then exit one way or another.
Does it make sense to add this in the commit message as well? I am
fine with either way.
For the patch:
Reviewed-by: Shakeel Butt <shakeelb@google.com>
next prev parent reply other threads:[~2021-01-12 21:55 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 16:30 [PATCH] mm: memcontrol: prevent starvation when writing memory.high Johannes Weiner
2021-01-12 17:03 ` Roman Gushchin
2021-01-12 19:45 ` Johannes Weiner
2021-01-12 20:12 ` Roman Gushchin
2021-01-12 21:11 ` Johannes Weiner
2021-01-12 21:45 ` Roman Gushchin
2021-01-15 15:34 ` Johannes Weiner
2021-01-12 18:59 ` Shakeel Butt
2021-01-12 19:53 ` Johannes Weiner
2021-01-12 20:28 ` Shakeel Butt [this message]
2021-01-13 14:46 ` Michal Hocko
2021-01-15 16:20 ` Johannes Weiner
2021-01-15 17:03 ` Roman Gushchin
2021-01-15 20:55 ` Johannes Weiner
2021-01-15 21:27 ` Roman Gushchin
2021-01-19 16:47 ` Johannes Weiner
2021-01-18 13:12 ` Michal Hocko
2021-01-13 17:25 ` Michal Koutný
2021-01-13 18:06 ` Roman Gushchin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CALvZod4qKrwvT7MAKrhemjrBfAAsk=fKa9g8QRij42j0CaF4nw@mail.gmail.com' \
--to=shakeelb@google.com \
--cc=akpm@linux-foundation.org \
--cc=cgroups@vger.kernel.org \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).