From: Oleg Nesterov <oleg@redhat.com>
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
linux-kernel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Subject: Re: [RFC] exit: do exit_task_work() before shooting off mm
Date: Sun, 20 Dec 2020 14:58:03 +0100 [thread overview]
Message-ID: <20201220135803.GA16470@redhat.com> (raw)
In-Reply-To: <ce5be208-99eb-f7bd-e602-9361008ff83c@gmail.com>
On 12/20, Pavel Begunkov wrote:
>
> On 08/12/2020 01:37, Al Viro wrote:
> > On Thu, Dec 03, 2020 at 02:30:46AM +0000, Pavel Begunkov wrote:
> >> Handle task works and lock it earlier before it starts killing off
> >> task's resources like mm. io_uring makes use of it a lot and it'd
> >> nicer to have all added task_work finding tasks in a consistent state.
I too do not understand this patch. task_work_add() will fail after
exit_task_work(). This means that, for example, exit_files() will use
schedule_delayed_work().
> One more moment, after we've set PF_EXITING any task_work_run() would be
> equivalent to exit_task_work()
Yes, currently task_work_run() can not be called after exit_signals().
And shouldn't be called imo ;)
> io_uring
> may want (currently doesn't) to run works for cancellation purposes.
Please see https://lore.kernel.org/io-uring/20200407163816.GB9655@redhat.com/
> Shouldn't it be like below (not tested)? Also simplifies task_work_run().
I'd prefer the patch from the link above, but your version looks correct too.
However, I still think it would be better to not abuse task_work_run() too
much...
Oleg.
next prev parent reply other threads:[~2020-12-20 13:59 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 2:30 [RFC] exit: do exit_task_work() before shooting off mm Pavel Begunkov
2020-12-08 1:37 ` Al Viro
2020-12-08 3:00 ` Pavel Begunkov
2020-12-20 12:50 ` Pavel Begunkov
2020-12-20 13:58 ` Oleg Nesterov [this message]
2020-12-20 14:42 ` Pavel Begunkov
2020-12-14 14:51 ` [exit] 80fae08355: stderr.mount:/fs/sda1:/dev/sda1_already_mounted_or_mount_point_busy kernel test robot
2020-12-14 14:51 ` kernel test robot
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=20201220135803.GA16470@redhat.com \
--to=oleg@redhat.com \
--cc=asml.silence@gmail.com \
--cc=axboe@kernel.dk \
--cc=linux-kernel@vger.kernel.org \
--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 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.