From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Don Brace To: Ming Lei , Jens Axboe , "linux-block@vger.kernel.org" , "Christoph Hellwig" , Mike Snitzer CC: "linux-scsi@vger.kernel.org" , Hannes Reinecke , Arun Easi , Omar Sandoval , "Martin K . Petersen" , "James Bottomley" , Christoph Hellwig , Kashyap Desai , Peter Rivera , Paolo Bonzini , "Laurence Oberman" Subject: RE: [PATCH V2 4/8] block: null_blk: introduce module parameter of 'g_global_tags' Date: Mon, 5 Feb 2018 20:26:33 +0000 Message-ID: <892b0510b3254668a1a1e5c5fb2f84c2@microsemi.com> References: <20180205152035.15016-1-ming.lei@redhat.com> <20180205152035.15016-5-ming.lei@redhat.com> In-Reply-To: <20180205152035.15016-5-ming.lei@redhat.com> Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Return-Path: don.brace@microsemi.com List-ID: > This patch introduces the parameter of 'g_global_tags' so that we can > test this feature by null_blk easiy. >=20 > Not see obvious performance drop with global_tags when the whole hw > depth is kept as same: >=20 > 1) no 'global_tags', each hw queue depth is 1, and 4 hw queues > modprobe null_blk queue_mode=3D2 nr_devices=3D4 shared_tags=3D1 global_ta= gs=3D0 > submit_queues=3D4 hw_queue_depth=3D1 >=20 > 2) 'global_tags', global hw queue depth is 4, and 4 hw queues > modprobe null_blk queue_mode=3D2 nr_devices=3D4 shared_tags=3D1 global_ta= gs=3D1 > submit_queues=3D4 hw_queue_depth=3D4 >=20 > 3) fio test done in above two settings: > fio --bs=3D4k --size=3D512G --rw=3Drandread --norandommap --direct=3D= 1 -- > ioengine=3Dlibaio --iodepth=3D4 --runtime=3D$RUNTIME --group_reporting=3D= 1 -- > name=3Dnullb0 --filename=3D/dev/nullb0 --name=3Dnullb1 --filename=3D/dev/= nullb1 -- > name=3Dnullb2 --filename=3D/dev/nullb2 --name=3Dnullb3 --filename=3D/dev/= nullb3 >=20 > 1M IOPS can be reached in both above tests which is done in one VM. >=20 I am getting 1.1M IOPS for both cases. Tested-by: Don Brace From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Brace Subject: RE: [PATCH V2 4/8] block: null_blk: introduce module parameter of 'g_global_tags' Date: Mon, 5 Feb 2018 20:26:33 +0000 Message-ID: <892b0510b3254668a1a1e5c5fb2f84c2@microsemi.com> References: <20180205152035.15016-1-ming.lei@redhat.com> <20180205152035.15016-5-ming.lei@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20180205152035.15016-5-ming.lei@redhat.com> Content-Language: en-US Sender: linux-block-owner@vger.kernel.org To: Ming Lei , Jens Axboe , "linux-block@vger.kernel.org" , Christoph Hellwig , Mike Snitzer Cc: "linux-scsi@vger.kernel.org" , Hannes Reinecke , Arun Easi , Omar Sandoval , "Martin K . Petersen" , James Bottomley , Christoph Hellwig , Kashyap Desai , Peter Rivera , Paolo Bonzini , Laurence Oberman List-Id: linux-scsi@vger.kernel.org > This patch introduces the parameter of 'g_global_tags' so that we can > test this feature by null_blk easiy. >=20 > Not see obvious performance drop with global_tags when the whole hw > depth is kept as same: >=20 > 1) no 'global_tags', each hw queue depth is 1, and 4 hw queues > modprobe null_blk queue_mode=3D2 nr_devices=3D4 shared_tags=3D1 global_ta= gs=3D0 > submit_queues=3D4 hw_queue_depth=3D1 >=20 > 2) 'global_tags', global hw queue depth is 4, and 4 hw queues > modprobe null_blk queue_mode=3D2 nr_devices=3D4 shared_tags=3D1 global_ta= gs=3D1 > submit_queues=3D4 hw_queue_depth=3D4 >=20 > 3) fio test done in above two settings: > fio --bs=3D4k --size=3D512G --rw=3Drandread --norandommap --direct=3D= 1 -- > ioengine=3Dlibaio --iodepth=3D4 --runtime=3D$RUNTIME --group_reporting=3D= 1 -- > name=3Dnullb0 --filename=3D/dev/nullb0 --name=3Dnullb1 --filename=3D/dev/= nullb1 -- > name=3Dnullb2 --filename=3D/dev/nullb2 --name=3Dnullb3 --filename=3D/dev/= nullb3 >=20 > 1M IOPS can be reached in both above tests which is done in one VM. >=20 I am getting 1.1M IOPS for both cases. Tested-by: Don Brace