From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: mhocko@kernel.org
Cc: linux-mm@kvack.org
Subject: Re: [PATCH 6/5] oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task
Date: Fri, 18 Mar 2016 00:20:41 +0900 [thread overview]
Message-ID: <201603180020.IGB30229.LOSFJQHtFVMOOF@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20160317145433.GG26017@dhcp22.suse.cz>
Michal Hocko wrote:
> > Strictly speaking, neither debug_show_all_locks() nor debug_show_held_locks()
> > are safe enough to guarantee that the system won't crash.
> >
> > commit 856848737bd944c1 "lockdep: fix debug_show_all_locks()"
> > commit 82a1fcb90287052a "softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks"
> >
> > They are convenient but we should avoid using them if we care about
> > possibility of crash.
>
> I really fail to see your point. debug_show_all_locks doesn't mention
> any restriction of the risk nor it is restricted to a particular
> context. Were there some bugs in that area? Probably yes, so what?
commit 856848737bd944c1 changed that locks held by TASK_RUNNING tasks
are not reported. We might fail to report the task which is holding mmap_sem
for write when we call debug_show_all_locks() in order to find such task.
Therefore, I think guessing from sched_show_task() output can be used.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-03-17 15:20 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 13:13 [PATCH 0/5] oom reaper v5 Michal Hocko
2016-02-03 13:13 ` [PATCH 1/5] mm, oom: introduce oom reaper Michal Hocko
2016-02-03 23:48 ` David Rientjes
2016-02-04 6:41 ` Michal Hocko
2016-02-06 13:22 ` Tetsuo Handa
2016-02-15 20:50 ` Michal Hocko
2016-02-03 13:13 ` [PATCH 2/5] oom reaper: handle mlocked pages Michal Hocko
2016-02-03 23:57 ` David Rientjes
2016-02-23 1:36 ` David Rientjes
2016-02-23 13:21 ` Michal Hocko
2016-02-29 3:19 ` Hugh Dickins
2016-02-29 13:41 ` Michal Hocko
2016-03-08 13:40 ` Michal Hocko
2016-03-08 20:07 ` Hugh Dickins
2016-03-09 8:26 ` Michal Hocko
2016-02-03 13:13 ` [PATCH 3/5] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Michal Hocko
2016-02-04 14:22 ` Tetsuo Handa
2016-02-04 14:43 ` Michal Hocko
2016-02-04 15:08 ` Tetsuo Handa
2016-02-04 16:31 ` Michal Hocko
2016-02-05 11:14 ` Tetsuo Handa
2016-02-06 8:30 ` Michal Hocko
2016-02-06 11:23 ` Tetsuo Handa
2016-02-15 20:47 ` Michal Hocko
2016-02-06 6:45 ` Michal Hocko
2016-02-06 14:33 ` Tetsuo Handa
2016-02-15 20:40 ` [PATCH 3.1/5] oom: make oom_reaper freezable Michal Hocko
2016-02-25 11:28 ` [PATCH 3/5] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Tetsuo Handa
2016-02-25 11:31 ` Tetsuo Handa
2016-02-25 14:16 ` Michal Hocko
2016-02-03 13:13 ` [PATCH 4/5] mm, oom_reaper: report success/failure Michal Hocko
2016-02-03 23:10 ` David Rientjes
2016-02-04 6:46 ` Michal Hocko
2016-02-04 22:31 ` David Rientjes
2016-02-05 9:26 ` Michal Hocko
2016-02-06 6:34 ` Michal Hocko
2016-02-03 13:14 ` [PATCH 5/5] mm, oom_reaper: implement OOM victims queuing Michal Hocko
2016-02-04 10:49 ` Tetsuo Handa
2016-02-04 14:53 ` Michal Hocko
2016-02-06 5:54 ` Tetsuo Handa
2016-02-06 8:37 ` Michal Hocko
2016-02-06 15:33 ` Tetsuo Handa
2016-02-15 20:15 ` Michal Hocko
2016-02-16 11:11 ` Tetsuo Handa
2016-02-16 15:53 ` Michal Hocko
2016-02-17 9:48 ` [PATCH 6/5] oom, oom_reaper: disable oom_reaper for Michal Hocko
2016-02-17 10:41 ` Tetsuo Handa
2016-02-17 11:33 ` Michal Hocko
2016-02-19 18:34 ` Michal Hocko
2016-02-20 2:32 ` [PATCH 6/5] oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task Tetsuo Handa
2016-02-22 9:41 ` Michal Hocko
2016-02-29 1:26 ` Tetsuo Handa
2016-03-15 11:15 ` Tetsuo Handa
2016-03-15 11:43 ` Michal Hocko
2016-03-15 11:50 ` Michal Hocko
2016-03-16 11:16 ` Tetsuo Handa
2016-03-17 10:49 ` Tetsuo Handa
2016-03-17 12:17 ` Michal Hocko
2016-03-17 13:00 ` Tetsuo Handa
2016-03-17 13:23 ` Michal Hocko
2016-03-17 14:34 ` Tetsuo Handa
2016-03-17 14:54 ` Michal Hocko
2016-03-17 15:20 ` Tetsuo Handa [this message]
2016-03-17 12:14 ` 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=201603180020.IGB30229.LOSFJQHtFVMOOF@I-love.SAKURA.ne.jp \
--to=penguin-kernel@i-love.sakura.ne.jp \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.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