From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@meta.com>,
linux-nvme@lists.infradead.org, sagi@grimberg.me, hch@lst.de,
Keith Busch <kbusch@kernel.org>,
Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Subject: Re: [PATCH] nvme-loop: set blocking flag
Date: Fri, 18 Oct 2024 07:10:14 +0200 [thread overview]
Message-ID: <20241018051014.GB19831@lst.de> (raw)
In-Reply-To: <7846e57b-fb03-42ed-af8e-0df88cc566a4@kernel.dk>
On Thu, Oct 17, 2024 at 11:39:24AM -0600, Jens Axboe wrote:
> On 10/17/24 11:20 AM, Keith Busch wrote:
> > From: Keith Busch <kbusch@kernel.org>
> >
> > Commit 505363957fad ("nvmet: fix nvme status code when namespace is
> > disabled") introduced a mutex lock in the io path for target. The loop
> > target connects this to the blk-mq submission side, so it requires the
> > blocking flag set so that queue_rq doesn't happen inside an rcu context.
>
> Looks fine to me, but might be worth looking at doing that a bit
> differently so that the target loop driver can remain non-blocking
> as it should be considerably more efficient.
Yes. When designing the nvmet code back in the day (gosh do I feel old)
we tried to avoid blocking in the main handling thread in general.
So if we can get rid of the mutex that would be great.
next prev parent reply other threads:[~2024-10-18 5:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-17 17:20 [PATCH] nvme-loop: set blocking flag Keith Busch
2024-10-17 17:36 ` Bart Van Assche
2024-10-17 17:39 ` Jens Axboe
2024-10-17 18:04 ` Keith Busch
2024-10-18 5:10 ` Christoph Hellwig
2024-10-20 21:35 ` Sagi Grimberg
2024-10-22 6:28 ` Christoph Hellwig
2024-10-22 7:02 ` Christoph Hellwig
2024-10-22 8:08 ` Shinichiro Kawasaki
2024-10-23 5:20 ` hch
2024-10-22 9:26 ` Sagi Grimberg
2024-10-22 9:25 ` Sagi Grimberg
2024-10-18 5:10 ` Christoph Hellwig [this message]
2024-10-18 4:19 ` Shinichiro Kawasaki
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