From: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
To: Tim Chen <tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>,
Vladimir Davydov
<vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Dave Hansen <dave.hansen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Ying Huang <ying.huang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 3/3] mm: Fix missing mem cgroup soft limit tree updates
Date: Tue, 9 Feb 2021 17:22:08 -0500 [thread overview]
Message-ID: <YCMLEB/2IscnaGGh@cmpxchg.org> (raw)
In-Reply-To: <3b6e4e9aa8b3ee1466269baf23ed82d90a8f791c.1612902157.git.tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Hello Tim,
On Tue, Feb 09, 2021 at 12:29:47PM -0800, Tim Chen wrote:
> @@ -6849,7 +6850,9 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
> * exclusive access to the page.
> */
>
> - if (ug->memcg != page_memcg(page)) {
> + if (ug->memcg != page_memcg(page) ||
> + /* uncharge batch update soft limit tree on a node basis */
> + (ug->dummy_page && ug->nid != page_to_nid(page))) {
The fix makes sense to me.
However, unconditionally breaking up the batch by node can
unnecessarily regress workloads in cgroups that do not have a soft
limit configured, and cgroup2 which doesn't have soft limits at
all. Consider an interleaving allocation policy for example.
Can you please further gate on memcg->soft_limit != PAGE_COUNTER_MAX,
or at least on !cgroup_subsys_on_dfl(memory_cgrp_subsys)?
Thanks
next prev parent reply other threads:[~2021-02-09 22:22 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 20:29 [PATCH 0/3] Soft limit memory management bug fixes Tim Chen
[not found] ` <cover.1612902157.git.tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2021-02-09 20:29 ` [PATCH 1/3] mm: Fix dropped memcg from mem cgroup soft limit tree Tim Chen
[not found] ` <d50e3bb513845d1f7816b94733576ce6f798682a.1612902157.git.tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2021-02-10 9:47 ` Michal Hocko
2021-02-09 20:29 ` [PATCH 2/3] mm: Force update of mem cgroup soft limit tree on usage excess Tim Chen
[not found] ` <90ef1dbc8ba6112794a3d09ecfed73f385f08eb7.1612902157.git.tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2021-02-10 9:51 ` Michal Hocko
2021-02-09 20:29 ` [PATCH 3/3] mm: Fix missing mem cgroup soft limit tree updates Tim Chen
[not found] ` <3b6e4e9aa8b3ee1466269baf23ed82d90a8f791c.1612902157.git.tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2021-02-09 22:22 ` Johannes Weiner [this message]
[not found] ` <YCMLEB/2IscnaGGh-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
2021-02-09 22:34 ` Tim Chen
2021-02-10 10:08 ` 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=YCMLEB/2IscnaGGh@cmpxchg.org \
--to=hannes-druugvl0lcnafugrpc6u6w@public.gmane.org \
--cc=akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org \
--cc=cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=dave.hansen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org \
--cc=mhocko-AlSwsSmVLrQ@public.gmane.org \
--cc=tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org \
--cc=vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
--cc=ying.huang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.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).