From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Cc: peterz@infradead.org
Subject: [PATCHSET 0/2] io_uring: use TWA_SIGNAL more carefully
Date: Sat, 8 Aug 2020 12:34:37 -0600 [thread overview]
Message-ID: <20200808183439.342243-1-axboe@kernel.dk> (raw)
Adding io_uring support to Netty, Josef noticed that there's another
case where we can fail to process task_work in time. We previously
added a "work-around" for eventfd, see:
b7db41c9e03b ("io_uring: fix regression with always ignoring signals in io_cqring_wait()")
but we can run into this dependency issue even without that. See the
test case added to liburing:
https://git.kernel.dk/cgit/liburing/tree/test/wakeup-hang.c
for an example of that. This series adds a split way to call
task_work_add(), so we can use TWA_SIGNAL if the task is currently
not running. This over-reaches a bit since there are definitely cases
where we do not need to use it, but better safe than sorry for now.
--
Jens Axboe
next reply other threads:[~2020-08-08 18:34 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-08 18:34 Jens Axboe [this message]
2020-08-08 18:34 ` [PATCH 1/2] kernel: split task_work_add() into two separate helpers Jens Axboe
2020-08-10 11:37 ` peterz
2020-08-10 15:01 ` Jens Axboe
2020-08-10 15:28 ` peterz
2020-08-10 17:51 ` Jens Axboe
2020-08-10 19:53 ` Peter Zijlstra
2020-08-08 18:34 ` [PATCH 2/2] io_uring: use TWA_SIGNAL for task_work if the task isn't running Jens Axboe
2020-08-10 11:42 ` peterz
2020-08-10 15:02 ` Jens Axboe
2020-08-10 19:21 ` Jens Axboe
2020-08-10 20:12 ` Peter Zijlstra
2020-08-10 20:13 ` Jens Axboe
2020-08-10 20:25 ` Jens Axboe
2020-08-10 20:32 ` Peter Zijlstra
2020-08-10 20:35 ` Jens Axboe
2020-08-10 20:35 ` Jann Horn
2020-08-10 21:06 ` Jens Axboe
2020-08-10 21:10 ` Peter Zijlstra
2020-08-10 21:12 ` Jens Axboe
2020-08-10 21:26 ` Jann Horn
2020-08-10 21:28 ` Jens Axboe
2020-08-10 22:01 ` Jens Axboe
2020-08-10 22:41 ` Jann Horn
2020-08-11 1:25 ` Jens Axboe
2020-08-11 6:45 ` Oleg Nesterov
2020-08-11 6:56 ` Peter Zijlstra
2020-08-11 7:14 ` Oleg Nesterov
2020-08-11 7:26 ` Oleg Nesterov
2020-08-11 7:49 ` Peter Zijlstra
2020-08-11 7:45 ` Peter Zijlstra
2020-08-11 8:10 ` Oleg Nesterov
2020-08-11 13:06 ` Jens Axboe
2020-08-11 14:05 ` Oleg Nesterov
2020-08-11 14:12 ` Jens Axboe
2020-08-10 21:27 ` Jens Axboe
2020-08-10 20:16 ` Jens Axboe
2020-08-13 16:25 ` Sasha Levin
2020-08-19 23:57 ` Sasha Levin
2020-08-19 23:59 ` Jens Axboe
2020-08-20 0:02 ` Jens Axboe
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