From: Oleg Nesterov <[email protected]>
To: Jens Axboe <[email protected]>
Cc: [email protected], [email protected],
Peter Zijlstra <[email protected]>
Subject: Re: [PATCH 4/4] io_uring: flush task work before waiting for ring exit
Date: Wed, 8 Apr 2020 22:17:35 +0200 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 04/08, Jens Axboe wrote:
>
> Here's some more data. I added a WARN_ON_ONCE() for task->flags &
> PF_EXITING on task_work_add() success, and it triggers with the
> following backtrace:
...
> which means that we've successfully added the task_work while the
> process is exiting.
but this is fine, task_work_add(task) can succeed if task->flags & EXITING.
task_work_add(task, work) should only fail if this "task" has already passed
exit_task_work(). Because if this task has already passed exit_task_work(),
nothing else can flush this work and call work->func().
Oleg.
next prev parent reply other threads:[~2020-04-08 20:17 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 16:02 [PATCHSET v2] io_uring and task_work interactions Jens Axboe
2020-04-07 16:02 ` [PATCH 1/4] task_work: add task_work_pending() helper Jens Axboe
2020-04-07 17:52 ` Jann Horn
2020-04-07 16:02 ` [PATCH 2/4] task_work: kill current->task_works checking in callers Jens Axboe
2020-04-07 16:02 ` [PATCH 3/4] task_work: make exit_work externally visible Jens Axboe
2020-04-07 16:02 ` [PATCH 4/4] io_uring: flush task work before waiting for ring exit Jens Axboe
2020-04-07 16:24 ` Oleg Nesterov
2020-04-07 16:38 ` Oleg Nesterov
2020-04-07 20:30 ` Jens Axboe
2020-04-07 20:39 ` Jens Axboe
2020-04-08 18:40 ` Oleg Nesterov
2020-04-08 18:48 ` Jens Axboe
2020-04-08 19:06 ` Jens Axboe
2020-04-08 20:17 ` Oleg Nesterov [this message]
2020-04-08 20:25 ` Jens Axboe
2020-04-08 21:19 ` Jens Axboe
2020-04-09 18:50 ` Oleg Nesterov
2020-04-10 0:29 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2020-04-06 19:48 [PATCHSET 0/4] io_uring and task_work interactions Jens Axboe
2020-04-06 19:48 ` [PATCH 4/4] io_uring: flush task work before waiting for ring exit Jens Axboe
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