From: Thomas Gleixner <tglx@linutronix.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: "linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] task_work: cleanup notification modes
Date: Sat, 17 Oct 2020 17:31:42 +0200 [thread overview]
Message-ID: <87tuusj2ch.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <7e32aa44-35ff-3a48-87d0-8e7df586db1d@kernel.dk>
On Fri, Oct 16 2020 at 17:43, Jens Axboe wrote:
> On 10/16/20 5:38 PM, Thomas Gleixner wrote:
> If you know the task isn't exiting, then yeah you can ignore it. But
> seems a bit dicey...
Indeed.
>> fs/io_uring.c- if (unlikely(ret)) {
>> fs/io_uring.c- struct task_struct *tsk;
>> fs/io_uring.c-
>> fs/io_uring.c- init_task_work(&req->task_work, io_req_task_cancel);
>> fs/io_uring.c- tsk = io_wq_get_task(req->ctx->io_wq);
>> fs/io_uring.c: task_work_add(tsk, &req->task_work, 0);
>> fs/io_uring.c- wake_up_process(tsk);
>>
>> yet more magic wakeup.
>
> It's not magic, but probably needs a comment... If we fail, that task is
> exiting. But we know we have our io-wq threads, so we use that as a
> fallback. Not really expected in the fast path.
I somehow misread it. So ignore me.
Thanks,
tglx
next prev parent reply other threads:[~2020-10-17 15:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-16 15:16 [PATCH] task_work: cleanup notification modes Jens Axboe
2020-10-16 21:44 ` Thomas Gleixner
2020-10-16 22:39 ` Jens Axboe
2020-10-16 23:09 ` Thomas Gleixner
2020-10-16 23:13 ` Jens Axboe
2020-10-16 23:38 ` Thomas Gleixner
2020-10-16 23:43 ` Jens Axboe
2020-10-17 15:31 ` Thomas Gleixner [this message]
2020-10-17 15:36 ` Jens Axboe
2020-10-17 20:18 ` Thomas Gleixner
2020-10-17 20:32 ` Jens Axboe
2020-10-17 21:01 ` Thomas Gleixner
2020-10-17 21:03 ` Jens Axboe
2020-10-17 21:17 ` Thomas Gleixner
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