From: Michal Hocko <mhocko@suse.com>
To: Zhaoyang Huang <huangzhaoyang@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
Zhaoyang Huang <zhaoyang.huang@unisoc.com>,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] mm: have kswapd only reclaiming use min protection on memcg
Date: Wed, 27 Oct 2021 10:26:14 +0200 [thread overview]
Message-ID: <YXkNJjD4axYlmqQ5@dhcp22.suse.cz> (raw)
In-Reply-To: <CAGWkznHVHVBrQEiO32p2uX_5BDUMc1fE64KuV34WJfpwC_23Pw@mail.gmail.com>
On Wed 27-10-21 15:46:19, Zhaoyang Huang wrote:
> On Wed, Oct 27, 2021 at 3:20 PM Michal Hocko <mhocko@suse.com> wrote:
> >
> > On Wed 27-10-21 15:01:50, Huangzhaoyang wrote:
> > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> > >
> > > For the kswapd only reclaiming, there is no chance to try again on
> > > this group while direct reclaim has. fix it by judging gfp flag.
> >
> > There is no problem description (same as in your last submissions. Have
> > you looked at the patch submission documentation as recommended
> > previously?).
> >
> > Also this patch doesn't make any sense. Both direct reclaim and kswapd
> > use a gfp mask which contains __GFP_DIRECT_RECLAIM (see balance_pgdat
> > for the kswapd part)..
> ok, but how does the reclaiming try with memcg's min protection on the
> alloc without __GFP_DIRECT_RECLAIM?
I do not follow. There is no need to protect memcg if the allocation
request doesn't have __GFP_DIRECT_RECLAIM because that would fail the
charge if a hard limit is reached, see try_charge_memcg and
gfpflags_allow_blocking check.
Background reclaim, on the other hand never breaches reclaim protection.
What is the actual problem you want to solve?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-10-27 8:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-27 7:01 [RFC PATCH] mm: have kswapd only reclaiming use min protection on memcg Huangzhaoyang
2021-10-27 7:20 ` Michal Hocko
2021-10-27 7:46 ` Zhaoyang Huang
2021-10-27 8:26 ` Michal Hocko [this message]
2021-10-27 9:19 ` Zhaoyang Huang
2021-10-27 11:52 ` Michal Hocko
2021-10-27 12:05 ` Zhaoyang Huang
2021-10-27 12:31 ` Michal Hocko
2021-10-28 0:45 ` Zhaoyang Huang
2021-10-28 2:04 ` Chris Down
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=YXkNJjD4axYlmqQ5@dhcp22.suse.cz \
--to=mhocko@suse.com \
--cc=akpm@linux-foundation.org \
--cc=hannes@cmpxchg.org \
--cc=huangzhaoyang@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=vdavydov.dev@gmail.com \
--cc=zhaoyang.huang@unisoc.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;
as well as URLs for NNTP newsgroup(s).