From: Johannes Weiner <hannes@cmpxchg.org>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
Michal Hocko <mhocko@kernel.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
Yafang Shao <shaoyafang@didiglobal.com>
Subject: Re: [PATCH v2] mm/memcontrol: keep local VM counters in sync with the hierarchical ones
Date: Thu, 11 Jul 2019 11:19:20 -0400 [thread overview]
Message-ID: <20190711151920.GA20341@cmpxchg.org> (raw)
In-Reply-To: <1562851979-10610-1-git-send-email-laoar.shao@gmail.com>
On Thu, Jul 11, 2019 at 09:32:59AM -0400, Yafang Shao wrote:
> After commit 815744d75152 ("mm: memcontrol: don't batch updates of local VM stats and events"),
> the local VM counters is not in sync with the hierarchical ones.
>
> Bellow is one example in a leaf memcg on my server (with 8 CPUs),
> inactive_file 3567570944
> total_inactive_file 3568029696
> We can find that the deviation is very great, that is because the 'val' in
> __mod_memcg_state() is in pages while the effective value in
> memcg_stat_show() is in bytes.
> So the maximum of this deviation between local VM stats and total VM
> stats can be (32 * number_of_cpu * PAGE_SIZE), that may be an unacceptable
> great value.
>
> We should keep the local VM stats in sync with the total stats.
> In order to keep this behavior the same across counters, this patch updates
> __mod_lruvec_state() and __count_memcg_events() as well.
>
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
> Cc: Yafang Shao <shaoyafang@didiglobal.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
next prev parent reply other threads:[~2019-07-11 15:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-11 13:32 [PATCH v2] mm/memcontrol: keep local VM counters in sync with the hierarchical ones Yafang Shao
2019-07-11 15:19 ` Johannes Weiner [this message]
2019-07-11 23:42 ` Andrew Morton
2019-07-12 1:47 ` Yafang Shao
2019-07-12 5:29 ` Michal Hocko
2019-07-12 6:12 ` Yafang Shao
2019-07-12 6:53 ` Michal Hocko
2019-07-12 7:14 ` Yafang Shao
2019-07-12 7:54 ` Michal Hocko
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=20190711151920.GA20341@cmpxchg.org \
--to=hannes@cmpxchg.org \
--cc=akpm@linux-foundation.org \
--cc=laoar.shao@gmail.com \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=shaoyafang@didiglobal.com \
--cc=vdavydov.dev@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.