From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Thumshirn Subject: Re: [LSF/MM TOPIC][LSF/MM ATTEND] NAPI polling for block drivers Date: Wed, 18 Jan 2017 14:51:56 +0100 Message-ID: <20170118135156.GG3514@linux-x5ow.site> References: <20170111134312.GH6286@linux-x5ow.site> <8b47ca34-d2ff-26dc-721e-2cb1e18f1efc@grimberg.me> <499af528-7810-f82d-1f11-cbf8f3a5b21c@grimberg.me> <53a3fb6c-c75a-519a-f669-2bcab404e01d@grimberg.me> <20170117162752.GE6067@linux-x5ow.site> <6df6bf6a-7cd3-1700-2b0a-e140325ebf47@grimberg.me> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <6df6bf6a-7cd3-1700-2b0a-e140325ebf47@grimberg.me> Sender: linux-block-owner@vger.kernel.org To: Sagi Grimberg Cc: Jens Axboe , Christoph Hellwig , Linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Keith Busch , "lsf-pc@lists.linux-foundation.org" List-Id: linux-scsi@vger.kernel.org On Tue, Jan 17, 2017 at 06:38:43PM +0200, Sagi Grimberg wrote: > > >Just for the record, all tests you've run are with the upper irq_poll_budget of > >256 [1]? > > Yes, but that's the point, I never ever reach this budget because > I'm only processing 1-2 completions per interrupt. > > >We (Hannes and me) recently stumbed accross this when trying to poll for more > >than 256 queue entries in the drivers we've been testing. s/stumbed/stumbled/ > > What do you mean by stumbed? irq-poll should be agnostic to the fact > that drivers can poll more than their given budget? So what you say is you saw a consomed == 1 [1] most of the time? [1] from http://git.infradead.org/nvme.git/commitdiff/eed5a9d925c59e43980047059fde29e3aa0b7836 -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850