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From: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
To: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Cc: Marta Rybczynska
	<mrybczyn-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>,
	Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>,
	linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	keith busch <keith.busch-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	axboe-b10kYP2dOMg@public.gmane.org,
	Samuel Jones
	<samuel.jones-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>,
	Max Gurtovoy <maxg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
	Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Subject: Re: [PATCH RFC] nvme-rdma: support devices with queue size < 32
Date: Wed, 29 Mar 2017 10:27:51 -0600	[thread overview]
Message-ID: <20170329162751.GA7113@obsidianresearch.com> (raw)
In-Reply-To: <406682b9-d7ca-4718-5830-7940d2822bc0-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>

On Wed, Mar 29, 2017 at 06:47:54PM +0300, Sagi Grimberg wrote:

> For each I/O we post up to 2 work requests, 1 for memory registration
> and 1 for sending an I/O request (and 1 for local invalidation if the
> target doesn't do it for us, but that is not the case here). So if our
> queue depth is X, we size our completion queue to be X*3, and we need
> to make sure we signal every (X*3)/2.

??? If your SQ is X and your CQ is X*3 you need to signal at X/2.

Jason
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  parent reply	other threads:[~2017-03-29 16:27 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-23  9:04 [PATCH RFC] nvme-rdma: support devices with queue size < 32 Marta Rybczynska
     [not found] ` <1315914765.312051621.1490259849534.JavaMail.zimbra-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>
2017-03-23 14:00   ` Christoph Hellwig
     [not found]     ` <20170323140042.GA30536-jcswGhMUV9g@public.gmane.org>
2017-03-23 14:36       ` Marta Rybczynska
     [not found]         ` <277345557.313693033.1490279818647.JavaMail.zimbra-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>
2017-03-28 11:09           ` Sagi Grimberg
     [not found]             ` <4951fac6-662f-29a6-5ba5-38d37a2c2dca-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-03-28 11:20               ` Marta Rybczynska
     [not found]                 ` <1180136633.325075447.1490700022740.JavaMail.zimbra-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>
2017-03-28 11:30                   ` Sagi Grimberg
     [not found]                     ` <8dc0414f-be90-ee30-0f66-8cee26c4c2aa-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-03-29  9:36                       ` Marta Rybczynska
2017-03-29 13:29                       ` Jason Gunthorpe
     [not found]                         ` <20170329132918.GA32072-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2017-03-29 15:47                           ` Sagi Grimberg
     [not found]                             ` <406682b9-d7ca-4718-5830-7940d2822bc0-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-03-29 16:27                               ` Jason Gunthorpe [this message]
     [not found]                                 ` <20170329162751.GA7113-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2017-03-29 16:39                                   ` Sagi Grimberg
     [not found]                                     ` <80770042-743e-a271-c636-f72099f9ac56-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-03-29 16:44                                       ` Doug Ledford
     [not found]                                         ` <9eb08168-18a6-a176-01df-b68b6a225963-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-03-29 16:47                                           ` Doug Ledford
     [not found]                                             ` <3505b835-d0ba-70cb-dfe8-1265fc2bbb83-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-03-29 16:59                                               ` Sagi Grimberg
     [not found]                                                 ` <2ba93b5b-ad36-5533-36e2-9db2e3198c19-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-03-29 22:19                                                   ` Jason Gunthorpe
2017-03-30 14:23                                                   ` Marta Rybczynska
     [not found]                                                     ` <1121115847.336382032.1490883808617.JavaMail.zimbra-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>
2017-04-06 12:29                                                       ` Marta Rybczynska
     [not found]                                                         ` <1224897571.353404199.1491481743295.JavaMail.zimbra-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>
2017-04-06 13:02                                                           ` Leon Romanovsky
     [not found]                                                             ` <20170406130207.GI2269-U/DQcQFIOTAAJjI8aNfphQ@public.gmane.org>
2017-04-07 13:31                                                               ` Marta Rybczynska
     [not found]                                                                 ` <1917497781.360337179.1491571916242.JavaMail.zimbra-FNhOzJFKnXGHXe+LvDLADg@public.gmane.org>
2017-04-09 12:31                                                                   ` Sagi Grimberg
     [not found]                                                                     ` <c7e56394-feb3-282b-0eec-166ef0d8b13c-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-04-10 11:29                                                                       ` Marta Rybczynska

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