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From: jgunthorpe@obsidianresearch.com (Jason Gunthorpe)
Subject: [PATCH v4, under testing] nvme-rdma: support devices with queue size < 32
Date: Wed, 3 May 2017 09:53:16 -0600	[thread overview]
Message-ID: <20170503155316.GA14334@obsidianresearch.com> (raw)
In-Reply-To: <780938034.8003164.1493824767084.JavaMail.zimbra@kalray.eu>

On Wed, May 03, 2017@05:19:27PM +0200, Marta Rybczynska wrote:

> > where
> >	queue->sig_limit = max(queue->queue_size / 2, 1);
> 
> I tried to avoid that because this adds a division in the fast path Bart
> was unhappy about in v2.

The compiler switches divide/multiply by powers of two into fast bit shifts.

Jason

  parent reply	other threads:[~2017-05-03 15:53 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-03 10:05 [PATCH v4, under testing] nvme-rdma: support devices with queue size < 32 Marta Rybczynska
2017-05-03 11:17 ` Leon Romanovsky
2017-05-03 15:08 ` Sagi Grimberg
2017-05-03 15:19   ` Marta Rybczynska
2017-05-03 15:45     ` Bart Van Assche
2017-05-03 15:53     ` Jason Gunthorpe [this message]
2017-05-03 15:58       ` Bart Van Assche
2017-05-03 16:01         ` Sagi Grimberg
2017-05-03 16:27           ` Leon Romanovsky
2017-05-03 16:37             ` Bart Van Assche
2017-05-03 16:49               ` Sagi Grimberg
2017-05-04 12:50               ` Marta Rybczynska
2017-05-17  9:02                 ` Christoph Hellwig
2017-05-17 12:50                   ` Marta Rybczynska
2017-05-03 16:17         ` Doug Ledford
2017-05-03 16:24           ` Bart Van Assche
2017-05-03 19:07             ` Doug Ledford

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