From: Michal Hocko <mhocko@suse.com>
To: "Huang, Ying" <ying.huang@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
Yang Shi <shy828301@gmail.com>, Wei Xu <weixugc@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Feng Tang <feng.tang@intel.com>
Subject: Re: memcg reclaim demotion wrt. isolation
Date: Wed, 14 Dec 2022 10:49:33 +0100 [thread overview]
Message-ID: <Y5mcLdBioMG+G9WS@dhcp22.suse.cz> (raw)
In-Reply-To: <87o7s6g09b.fsf@yhuang6-desk2.ccr.corp.intel.com>
On Wed 14-12-22 10:57:52, Huang, Ying wrote:
> Michal Hocko <mhocko@suse.com> writes:
[...]
> > This makes sense but I suspect that this wasn't intended also for
> > memcg triggered reclaim. This would mean that a memory pressure in one
> > hierarchy could trigger paging out pages of a different hierarchy if the
> > demotion target is close to full.
>
> It seems that it's unnecessary to wake up kswapd of demotion target node
> in most cases. Because we will try to reclaim on the demotion target
> nodes in the loop of do_try_to_free_pages(). It may be better to loop
> the zonelist in the reverse order. Because the demotion targets are
> usually located at the latter of the zonelist.
Reclaiming from demotion targets first would deal with that as well.
Thanks! Let's establish whether this is something we really need/want
fix first.
--
Michal Hocko
SUSE Labs
prev parent reply other threads:[~2022-12-14 9:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-13 15:41 Michal Hocko
2022-12-13 16:14 ` Johannes Weiner
2022-12-14 9:42 ` Michal Hocko
2022-12-14 12:40 ` Johannes Weiner
2022-12-14 15:29 ` Michal Hocko
2022-12-14 17:40 ` Johannes Weiner
2022-12-15 6:17 ` Huang, Ying
2022-12-15 8:22 ` Johannes Weiner
2022-12-16 3:16 ` Huang, Ying
2022-12-13 22:26 ` Dave Hansen
2022-12-14 9:45 ` Michal Hocko
2022-12-14 2:57 ` Huang, Ying
2022-12-14 9:49 ` Michal Hocko [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=Y5mcLdBioMG+G9WS@dhcp22.suse.cz \
--to=mhocko@suse.com \
--cc=akpm@linux-foundation.org \
--cc=dave.hansen@intel.com \
--cc=feng.tang@intel.com \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=shy828301@gmail.com \
--cc=weixugc@google.com \
--cc=ying.huang@intel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox