From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [LSF/MM TOPIC][LSF/MM ATTEND] NAPI polling for block drivers Date: Wed, 11 Jan 2017 16:26:40 +0000 Message-ID: <1484151982.2619.6.camel@sandisk.com> References: <20170111134312.GH6286@linux-x5ow.site> <1484150893.2619.1.camel@sandisk.com> <20170111161238.GA18881@infradead.org> <2aff05af-5e83-7d3d-f879-2cce02b6d88c@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <2aff05af-5e83-7d3d-f879-2cce02b6d88c@suse.de> Content-Language: en-US Content-ID: Sender: linux-block-owner@vger.kernel.org To: "hch@infradead.org" , "hare@suse.de" Cc: "Linux-scsi@vger.kernel.org" , "keith.busch@intel.com" , "jthumshirn@suse.de" , "linux-nvme@lists.infradead.org" , "lsf-pc@lists.linux-foundation.org" , "linux-block@vger.kernel.org" , "sagi@grimberg.me" List-Id: linux-scsi@vger.kernel.org On Wed, 2017-01-11 at 17:22 +0100, Hannes Reinecke wrote: > On 01/11/2017 05:12 PM, hch@infradead.org wrote: > > On Wed, Jan 11, 2017 at 04:08:31PM +0000, Bart Van Assche wrote: > > > A typical Ethernet network adapter delays the generation of an > > > interrupt > > > after it has received a packet. A typical block device or HBA does no= t > > > delay > > > the generation of an interrupt that reports an I/O completion. > >=20 > > NVMe allows for configurable interrupt coalescing, as do a few modern > > SCSI HBAs. >=20 > Essentially every modern SCSI HBA does interrupt coalescing; otherwise > the queuing interface won't work efficiently. Hello Hannes, The first e-mail in this e-mail thread referred to measurements against a block device for which interrupt coalescing was not enabled. I think that the measurements have to be repeated against a block device for which interrupt coalescing is enabled. Bart.=