All of lore.kernel.org
 help / color / mirror / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-mm <linux-mm@kvack.org>, Mel Gorman <mgorman@suse.de>,
	Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH] mm: avoid blocking lock_page() in kcompactd
Date: Mon, 27 Jan 2020 15:49:31 +0100	[thread overview]
Message-ID: <20200127144931.GM1183@dhcp22.suse.cz> (raw)
In-Reply-To: <CAM_iQpU0p7JLyQ4mQ==Kd7+0ugmricsEAp1ST2ShAZar2BLAWg@mail.gmail.com>

On Sun 26-01-20 11:53:55, Cong Wang wrote:
> On Tue, Jan 21, 2020 at 1:00 AM Michal Hocko <mhocko@kernel.org> wrote:
> >
> > On Mon 20-01-20 14:48:05, Cong Wang wrote:
> > > It got stuck somewhere along the call path of mem_cgroup_try_charge(),
> > > and the trace events of mm_vmscan_lru_shrink_inactive() indicates this
> > > too:
> >
> > So it seems that you are condending on the page lock. It is really
> > unexpected that the reclaim would take that long though. Please try to
> > enable more vmscan tracepoints to see where the time is spent.
> 
> Sorry for the delay. I have been trying to collect more data in one shot.
> 
> This is a a typical round of the loop after enabling all vmscan tracepoints:
> 
>            <...>-455450 [007] .... 4048595.842992:
> mm_vmscan_memcg_reclaim_begin: order=0 may_writepage=1
> gfp_flags=GFP_NOFS|__GFP_HIGHMEM|__GFP_HARDWALL|__GFP_MOVABLE
> classzone_idx=4
>            <...>-455450 [007] .... 4048595.843012:
> mm_vmscan_memcg_reclaim_end: nr_reclaimed=0

This doesn't tell us much though. This reclaim round has taken close to
no time. See timestamps.

> The whole trace output is huge (33M), I can provide it on request.

Focus on reclaim rounds that take a long time and see where it gets you.
-- 
Michal Hocko
SUSE Labs

  parent reply	other threads:[~2020-01-27 14:49 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09 22:56 [PATCH] mm: avoid blocking lock_page() in kcompactd Cong Wang
2020-01-10  0:28 ` Yang Shi
2020-01-10  0:28   ` Yang Shi
2020-01-10  1:01   ` Cong Wang
2020-01-10  1:01     ` Cong Wang
2020-01-10  4:51     ` Cong Wang
2020-01-10  4:51       ` Cong Wang
2020-01-10  7:38 ` Michal Hocko
2020-01-20 22:48   ` Cong Wang
2020-01-20 22:48     ` Cong Wang
2020-01-21  9:00     ` Michal Hocko
2020-01-26 19:53       ` Cong Wang
2020-01-26 19:53         ` Cong Wang
2020-01-26 23:39         ` Matthew Wilcox
2020-01-27 15:00           ` Michal Hocko
2020-01-27 19:06             ` Matthew Wilcox
2020-01-28  1:25               ` Yang Shi
2020-01-28  1:25                 ` Yang Shi
2020-01-28  6:03                 ` Matthew Wilcox
2020-01-28  8:17               ` Michal Hocko
2020-01-28  8:30                 ` Matthew Wilcox
2020-01-28  9:13                   ` Michal Hocko
2020-01-28 10:48                     ` Matthew Wilcox
2020-01-28 11:39                       ` Michal Hocko
2020-01-28 19:44                         ` Cong Wang
2020-01-28 19:44                           ` Cong Wang
2020-01-30 22:52                           ` Cong Wang
2020-01-30 22:52                             ` Cong Wang
2020-02-13  7:48                         ` Michal Hocko
2020-02-13 16:46                           ` Matthew Wilcox
2020-02-13 17:08                             ` Michal Hocko
2020-02-14  4:27                               ` Matthew Wilcox
2020-02-14  6:55                                 ` Michal Hocko
2020-01-27 14:49         ` Michal Hocko [this message]
2020-01-28  0:46           ` Cong Wang
2020-01-28  0:46             ` Cong Wang
2020-01-28  8:22             ` Michal Hocko
2020-01-10  9:22 ` Mel Gorman
2020-01-20 22:41   ` Cong Wang
2020-01-20 22:41     ` Cong Wang
2020-01-21 19:21     ` Yang Shi
2020-01-21 19:21       ` Yang Shi
2020-01-21  8:26   ` Hillf Danton
2020-01-21  9:06     ` 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=20200127144931.GM1183@dhcp22.suse.cz \
    --to=mhocko@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@suse.de \
    --cc=vbabka@suse.cz \
    --cc=xiyou.wangcong@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.