From: Shakeel Butt <shakeelb@google.com>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>,
Johannes Weiner <hannes@cmpxchg.org>, Tejun Heo <tj@kernel.org>,
Jan Kara <jack@suse.cz>,
Roman Gushchin <roman.gushchin@linux.dev>,
Michal Hocko <mhocko@kernel.org>,
Muchun Song <muchun.song@linux.dev>,
cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: writeback: ratelimit stat flush from mem_cgroup_wb_stats
Date: Mon, 22 Jan 2024 10:19:10 -0800 [thread overview]
Message-ID: <CALvZod4XUrQMxptBo56Fm6-ETQy_DtVq-g4NKokVvSyGwDOnxg@mail.gmail.com> (raw)
In-Reply-To: <jazycqhefxn6oigmt6mitn2cfoonscbdwqxy5g7gs2j74w3ia5@qwcu3v7kmk4h>
On Mon, Jan 22, 2024 at 7:20 AM Michal Koutný <mkoutny@suse.com> wrote:
>
> Hello.
>
> On Thu, Jan 18, 2024 at 06:42:35PM +0000, Shakeel Butt <shakeelb@google.com> wrote:
> > One of our workloads (Postgres 14) has regressed when migrated from 5.10
> > to 6.1 upstream kernel. The regression can be reproduced by sysbench's
> > oltp_write_only benchmark.
> > It seems like the always on rstat flush in
> > mem_cgroup_wb_stats() is causing the regression.
>
> Is the affected benchmark running in a non-root cgroup?
>
> I'm asking whether this would warrant a
> Fixes: fd25a9e0e23b ("memcg: unify memcg stat flushing")
> that introduced the global flush (in v6.1) but it was removed later in
> 7d7ef0a4686a ("mm: memcg: restore subtree stats flushing")
> (so v6.8 could be possibly unaffected).
>
Yes, the benchmark and the workload were running in non-root cgroups.
Regarding the Fixes, please note that the regression was still there
with 7d7ef0a4686a ("mm: memcg: restore subtree stats flushing"), so I
would say that our first conversion to rstat infra would most probably
have the issue as well which was 2d146aa3aa84 ("mm: memcontrol: switch
to rstat").
So, the following fixes tag makes sense to me:
Fixes: 2d146aa3aa84 ("mm: memcontrol: switch to rstat")
prev parent reply other threads:[~2024-01-22 18:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-18 18:42 [PATCH] mm: writeback: ratelimit stat flush from mem_cgroup_wb_stats Shakeel Butt
2024-01-18 19:19 ` Johannes Weiner
2024-01-18 22:42 ` Roman Gushchin
2024-01-22 15:20 ` Michal Koutný
2024-01-22 18:19 ` Shakeel Butt [this message]
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=CALvZod4XUrQMxptBo56Fm6-ETQy_DtVq-g4NKokVvSyGwDOnxg@mail.gmail.com \
--to=shakeelb@google.com \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=cgroups@vger.kernel.org \
--cc=hannes@cmpxchg.org \
--cc=jack@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mkoutny@suse.com \
--cc=muchun.song@linux.dev \
--cc=roman.gushchin@linux.dev \
--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).