From: keith.busch@linux.intel.com (Keith Busch)
Subject: [PATCH] nvme: handle completions outside of the queue lock
Date: Thu, 17 May 2018 09:32:52 -0600 [thread overview]
Message-ID: <20180517153251.GB23555@localhost.localdomain> (raw)
In-Reply-To: <20180517152909.GA19042@infradead.org>
On Thu, May 17, 2018@08:29:09AM -0700, Christoph Hellwig wrote:
> On Thu, May 17, 2018@09:03:52AM -0600, Keith Busch wrote:
> > > + if (nvme_handle_cqe(nvmeq, start, tag))
> > > + return 1;
> >
> > We can't return early from here anymore since the new interface moved
> > the CQ head. No one else is going to get to see those completions, so
> > the first caller owns completing everything up to the end that it claimed.
>
> Indeed. So either we have to complete everything, or we have to not
> do the batch processing for the poll case. Given that when we're
> polling we have a QD approaching one on a given core I suspect not
> batching for the poll case might be the right answer, but someone
> will have to run the numbers.
Maybe the batch can take the tag and stop moving the head when it finds
a match?
next prev parent reply other threads:[~2018-05-17 15:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-17 3:23 [PATCH] nvme: handle completions outside of the queue lock Jens Axboe
2018-05-17 3:47 ` Keith Busch
2018-05-17 7:16 ` Christoph Hellwig
2018-05-17 7:47 ` Christoph Hellwig
2018-05-17 14:21 ` Jens Axboe
2018-05-17 15:03 ` Keith Busch
2018-05-17 15:29 ` Christoph Hellwig
2018-05-17 15:32 ` Keith Busch [this message]
2018-05-17 14:21 ` Keith Busch
2018-05-17 14:22 ` Jens Axboe
2018-05-17 15:30 ` Christoph Hellwig
2018-05-17 15:33 ` Jens Axboe
2018-05-17 15:35 ` Christoph Hellwig
2018-05-17 15:35 ` Jens Axboe
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