From: Mikulas Patocka <mpatocka@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>, Alasdair Kergon <agk@redhat.com>,
Mike Snitzer <snitzer@kernel.org>,
linux-block@vger.kernel.org, dm-devel@lists.linux.dev
Subject: Re: [PATC] block: update queue limits atomically
Date: Wed, 19 Mar 2025 22:18:39 +0100 (CET) [thread overview]
Message-ID: <d04fcd9f-b4a7-100a-e9a4-b0d4d45b372b@redhat.com> (raw)
In-Reply-To: <6ebdd2ae-8fc2-4072-b131-a7c0da56d3f2@kernel.dk>
On Tue, 18 Mar 2025, Jens Axboe wrote:
> > Yeah, it looks fine, but I feel it is still fragile, and not sure it is one
> > accepted solution.
>
> Agree - it'd be much better to have the bio drivers provide the same
> guarantees that we get on the request side, rather than play games with
> this and pretend that concurrent update and usage is fine.
>
> --
> Jens Axboe
And what mechanism should they use to read the queue limits?
* locking? (would degrade performance)
* percpu-rwsem? (no overhead for readers, writers wait for the RCU
synchronization)
* RCU?
* anything else?
Mikulas
next prev parent reply other threads:[~2025-03-19 21:18 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-18 14:26 [PATC] block: update queue limits atomically Mikulas Patocka
2025-03-18 14:56 ` Ming Lei
2025-03-18 15:31 ` Mikulas Patocka
2025-03-19 1:22 ` Ming Lei
2025-03-19 1:58 ` Jens Axboe
2025-03-19 21:18 ` Mikulas Patocka [this message]
2025-03-20 2:22 ` Ming Lei
2025-03-20 12:58 ` Jens Axboe
2025-03-20 5:26 ` Christoph Hellwig
2025-03-18 15:58 ` Bart Van Assche
2025-03-18 16:13 ` Mikulas Patocka
2025-03-20 5:25 ` Christoph Hellwig
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