From: Jens Axboe <axboe@kernel.dk>
To: Christoph Hellwig <hch@infradead.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Mike Snitzer <msnitzer@redhat.com>,
Damien Le Moal <dlemoal@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Waiman Long <longman@redhat.com>,
Guangwu Zhang <guazhang@redhat.com>,
dm-devel@lists.linux.dev, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] completion: move blk_wait_io to kernel/sched/completion.c
Date: Thu, 18 Apr 2024 09:09:07 -0600 [thread overview]
Message-ID: <362c3c63-6fd9-401c-9281-e2e0c7efc14a@kernel.dk> (raw)
In-Reply-To: <ZiEyLvL6Pq_RB-Eh@infradead.org>
On 4/18/24 8:46 AM, Christoph Hellwig wrote:
> On Thu, Apr 18, 2024 at 08:30:14AM -0600, Jens Axboe wrote:
>> It certainly is a hack/work-around, but unless there are a lot more that
>> should be using something like this, I don't think adding extra core
>> complexity in terms of a special task state (or per-task flag, at least
>> that would be easier) is really warranted.
>
> Basically any kernel thread doing on-demand work has the same problem.
> It just has an easier workaround hack, as the kernel threads can simply
> claim to do an interruptible sleep to not trigger the softlockup
> warnings.
A kernel thread can just use TASK_INTERRUPTIBLE, as it doesn't take
signals anyway. But yeah, I guess you could view that as a work-around
as well.
Outside of that, mostly only a block problem, where our sleep is always
uninterruptible. Unless there are similar hacks elsewhere in the kernel
that I'm not aware of?
--
Jens Axboe
next prev parent reply other threads:[~2024-04-18 15:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-17 17:49 [PATCH 1/2] completion: move blk_wait_io to kernel/sched/completion.c Mikulas Patocka
2024-04-17 17:55 ` Peter Zijlstra
2024-04-17 18:00 ` Mikulas Patocka
2024-04-18 4:57 ` Christoph Hellwig
2024-04-18 14:30 ` Jens Axboe
2024-04-18 14:46 ` Christoph Hellwig
2024-04-18 15:09 ` Jens Axboe [this message]
2024-04-22 10:59 ` Peter Zijlstra
2024-04-23 12:36 ` Mikulas Patocka
2024-04-26 6:06 ` Christoph Hellwig
2024-04-22 10:54 ` Peter Zijlstra
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