From: Oleg Nesterov <oleg@redhat.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Chanho Min <chanho.min@lge.com>,
"'Rafael J. Wysocki'" <rjw@rjwysocki.net>,
'Pavel Machek' <pavel@ucw.cz>, 'Len Brown' <len.brown@intel.com>,
'Andrew Morton' <akpm@linux-foundation.org>,
"'Eric W. Biederman'" <ebiederm@xmission.com>,
'Christian Brauner' <christian@brauner.io>,
'Anna-Maria Gleixner' <anna-maria@linutronix.de>,
'Alexander Viro' <viro@zeniv.linux.org.uk>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
'Seungho Park' <seungho1.park@lge.com>,
'Inkyu Hwang' <inkyu.hwang@lge.com>,
'Donghwan Jung' <donghwan.jung@lge.com>,
'Jongsung Kim' <neidhard.kim@lge.com>
Subject: Re: [PATCH v2] exec: make de_thread() freezable
Date: Wed, 14 Nov 2018 15:37:06 +0100 [thread overview]
Message-ID: <20181114143705.GB13885@redhat.com> (raw)
In-Reply-To: <20181114103014.GN23419@dhcp22.suse.cz>
On 11/14, Michal Hocko wrote:
>
> > I don't understand why it isn't appropriate for exec to block. The
> > exec can freeze. When tasks are thawed, the killed sub-thread will die
> > and wake de_thread(). The exec will continue to work from resume.
>
> Because this is fragile.
I don't really agree, but...
> I haven't checked the full set of resources the
> task holds when in this path but I can imagine we can introduce lock
> dependency on freezing really easily.
And you are right, see another email I sent you a minute ago.
But again, we need to change de_thread to sleep without cred_guard_mutex
anyway, so I think this change is fine. At least in that it can't add the
new problems.
Oleg.
next prev parent reply other threads:[~2018-11-14 14:37 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 3:54 [PATCH v2] exec: make de_thread() freezable Chanho Min
2018-11-12 8:15 ` Oleg Nesterov
2018-11-21 23:35 ` Rafael J. Wysocki
2018-11-12 9:51 ` Pavel Machek
2018-11-13 14:53 ` Michal Hocko
2018-11-13 16:18 ` Oleg Nesterov
2018-11-13 18:00 ` Michal Hocko
2018-11-14 10:18 ` Chanho Min
2018-11-14 10:30 ` Michal Hocko
2018-11-14 14:37 ` Oleg Nesterov [this message]
2018-11-14 14:29 ` Oleg Nesterov
2018-11-14 11:31 ` 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=20181114143705.GB13885@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=anna-maria@linutronix.de \
--cc=chanho.min@lge.com \
--cc=christian@brauner.io \
--cc=donghwan.jung@lge.com \
--cc=ebiederm@xmission.com \
--cc=inkyu.hwang@lge.com \
--cc=len.brown@intel.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mhocko@kernel.org \
--cc=neidhard.kim@lge.com \
--cc=pavel@ucw.cz \
--cc=rjw@rjwysocki.net \
--cc=seungho1.park@lge.com \
--cc=viro@zeniv.linux.org.uk \
/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).