From: Oleg Nesterov <oleg@redhat.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Kyle Walker <kwalker@redhat.com>,
Stanislav Kozina <skozina@redhat.com>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm v2 1/3] mm/oom_kill: remove the wrong fatal_signal_pending() check in oom_kill_process()
Date: Thu, 1 Oct 2015 17:00:10 +0200 [thread overview]
Message-ID: <20151001150010.GB6781@redhat.com> (raw)
In-Reply-To: <20151001124941.GC24077@dhcp22.suse.cz>
On 10/01, Michal Hocko wrote:
>
> On Wed 30-09-15 20:24:05, Oleg Nesterov wrote:
> [...]
> > It is possible that the group leader
> > has the pending SIGKILL because its sub-thread originated the coredump,
> > in this case we must not skip this process.
>
> I do not understand this. If the group leader has SIGKILL pending it
> will die anyway regardless whether we send another sigkill or not, no?
Yes it will die, but only after the coredump is finished.
Suppose we have a thread group with the group leader P and another
thread T. If T starts the coredump, it sends SIGKILL to P and waits
until it parks in exit_mm(). Then T actually dumps the core which may
need more memory, a lot of time, etc.
We need to kill this process. Yes, P is already killed and it sleeps
in TASK_UNINTERRUPTIBLE so this thread does not need SIGKILL. But
do_send_sig_info(P) will also find T and kill it too to make
dump_interrupted() == T.
Oleg.
next prev parent reply other threads:[~2015-10-01 15:03 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-29 14:17 [PATCH -mm 0/3] mm/oom_kill: ensure we actually kill all tasks sharing the same mm Oleg Nesterov
2015-09-29 14:18 ` [PATCH -mm 1/3] mm/oom_kill: remove the wrong fatal_signal_pending() Oleg Nesterov
2015-09-29 22:36 ` David Rientjes
2015-09-30 1:42 ` Tetsuo Handa
2015-09-30 13:47 ` Oleg Nesterov
2015-09-30 15:20 ` [PATCH -mm 1/3] mm/oom_kill: remove the wrongfatal_signal_pending() Tetsuo Handa
2015-09-30 13:43 ` [PATCH -mm 1/3] mm/oom_kill: remove the wrong fatal_signal_pending() Oleg Nesterov
2015-09-29 14:18 ` [PATCH -mm 2/3] mm/oom_kill: cleanup the "kill sharing same memory" Oleg Nesterov
2015-09-29 22:39 ` David Rientjes
2015-09-30 13:49 ` Oleg Nesterov
2015-09-29 14:18 ` [PATCH -mm 3/3] mm/oom_kill: fix the wrong task->mm == mm checks in Oleg Nesterov
2015-09-29 22:41 ` David Rientjes
2015-09-30 13:50 ` Oleg Nesterov
2015-09-30 2:16 ` Tetsuo Handa
2015-09-30 13:59 ` Oleg Nesterov
2015-09-30 18:23 ` [PATCH -mm v2 0/3] mm/oom_kill: ensure we actually kill all tasks sharing the same mm Oleg Nesterov
2015-09-30 18:24 ` [PATCH -mm v2 1/3] mm/oom_kill: remove the wrong fatal_signal_pending() check in oom_kill_process() Oleg Nesterov
2015-09-30 21:14 ` David Rientjes
2015-10-01 10:52 ` [PATCH -mm v2 1/3] mm/oom_kill: remove the wrong fatal_signal_pending()check " Tetsuo Handa
2015-10-01 12:49 ` [PATCH -mm v2 1/3] mm/oom_kill: remove the wrong fatal_signal_pending() check " Michal Hocko
2015-10-01 15:00 ` Oleg Nesterov [this message]
2015-10-01 15:27 ` Michal Hocko
2015-10-01 15:41 ` Oleg Nesterov
2015-10-01 16:19 ` Michal Hocko
2015-10-01 17:53 ` Oleg Nesterov
2015-10-02 11:32 ` Tetsuo Handa
2015-10-02 12:11 ` Michal Hocko
2015-10-02 12:33 ` Tetsuo Handa
2015-10-02 13:32 ` Michal Hocko
2015-10-02 13:57 ` Oleg Nesterov
2015-10-02 14:24 ` Michal Hocko
2015-10-02 14:07 ` Tetsuo Handa
2015-10-02 14:15 ` Oleg Nesterov
2015-10-02 13:52 ` Oleg Nesterov
2015-10-02 14:36 ` Tetsuo Handa
2015-09-30 18:24 ` [PATCH -mm v2 2/3] mm/oom_kill: cleanup the "kill sharing same memory" loop Oleg Nesterov
2015-09-30 21:15 ` David Rientjes
2015-10-01 12:50 ` Michal Hocko
2015-09-30 18:24 ` [PATCH -mm v2 3/3] mm/oom_kill: fix the wrong task->mm == mm checks in oom_kill_process() Oleg Nesterov
2015-09-30 21:15 ` David Rientjes
2015-10-01 12:56 ` Michal Hocko
2015-10-01 22:24 ` Andrew Morton
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=20151001150010.GB6781@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=kwalker@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mhocko@kernel.org \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=rientjes@google.com \
--cc=skozina@redhat.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).