From: Jann Horn <jannh@google.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <peterz@infradead.org>,
io-uring <io-uring@vger.kernel.org>,
stable <stable@vger.kernel.org>, Josef <josef.grieb@gmail.com>,
Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH 2/2] io_uring: use TWA_SIGNAL for task_work if the task isn't running
Date: Mon, 10 Aug 2020 23:26:55 +0200 [thread overview]
Message-ID: <CAG48ez2dEyxe_ioQaDC3JTdSyLsdOiFKZvk6LGP00ELSfSvhvg@mail.gmail.com> (raw)
In-Reply-To: <5628f79b-6bfb-b054-742a-282663cb2565@kernel.dk>
On Mon, Aug 10, 2020 at 11:12 PM Jens Axboe <axboe@kernel.dk> wrote:
> On 8/10/20 3:10 PM, Peter Zijlstra wrote:
> > On Mon, Aug 10, 2020 at 03:06:49PM -0600, Jens Axboe wrote:
> >
> >> should work as far as I can tell, but I don't even know if there's a
> >> reliable way to do task_in_kernel().
> >
> > Only on NOHZ_FULL, and tracking that is one of the things that makes it
> > so horribly expensive.
>
> Probably no other way than to bite the bullet and just use TWA_SIGNAL
> unconditionally...
Why are you trying to avoid using TWA_SIGNAL? Is there a specific part
of handling it that's particularly slow?
next prev parent reply other threads:[~2020-08-10 21:27 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-08 18:34 [PATCHSET 0/2] io_uring: use TWA_SIGNAL more carefully Jens Axboe
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 [this message]
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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