lkml.org 
[lkml]   [2018]   [Jun]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: dm bufio: Reduce dm_bufio_lock contention


On Tue, 12 Jun 2018, Mike Snitzer wrote:

> On Tue, Jun 12 2018 at 4:03am -0400,
> Jing Xia <jing.xia.mail@gmail.com> wrote:
>
> > Performance test in android reports that the phone sometimes gets
> > hanged and shows black screen for about several minutes.The sysdump shows:
> > 1. kswapd and other tasks who enter the direct-reclaim path are waiting
> > on the dm_bufio_lock;
>
> Do you have an understanding of where they are waiting? Is it in
> dm_bufio_shrink_scan()?
>
> > 2. the task who gets the dm_bufio_lock is stalled for IO completions,
> > the relevant stack trace as :
> >
> > PID: 22920 TASK: ffffffc0120f1a00 CPU: 1 COMMAND: "kworker/u8:2"
> > #0 [ffffffc0282af3d0] __switch_to at ffffff8008085e48
> > #1 [ffffffc0282af3f0] __schedule at ffffff8008850cc8
> > #2 [ffffffc0282af450] schedule at ffffff8008850f4c
> > #3 [ffffffc0282af470] schedule_timeout at ffffff8008853a0c
> > #4 [ffffffc0282af520] schedule_timeout_uninterruptible at ffffff8008853aa8
> > #5 [ffffffc0282af530] wait_iff_congested at ffffff8008181b40
> > #6 [ffffffc0282af5b0] shrink_inactive_list at ffffff8008177c80
> > #7 [ffffffc0282af680] shrink_lruvec at ffffff8008178510
> > #8 [ffffffc0282af790] mem_cgroup_shrink_node_zone at ffffff80081793bc
> > #9 [ffffffc0282af840] mem_cgroup_soft_limit_reclaim at ffffff80081b6040

Please send the full stacktrace of this task.

Then, we can see, why is it waiting here.

Mikulas

\
 
 \ /
  Last update: 2018-06-13 16:03    [W:0.043 / U:1.512 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site