From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933524AbdKPJrE (ORCPT ); Thu, 16 Nov 2017 04:47:04 -0500 Received: from mailout4.samsung.com ([203.254.224.34]:27180 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758343AbdKPJqp (ORCPT ); Thu, 16 Nov 2017 04:46:45 -0500 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20171116094643epoutp04a128ca88d9abdf225d27c9e8c8a9e489~3h_HAWzBT1937419374epoutp04K X-AuditID: b6c32a36-325ff70000001039-68-5a0d5e83e4db From: Bartlomiej Zolnierkiewicz To: Adrian Hunter Cc: Ulf Hansson , linux-mmc , linux-block , linux-kernel , Bough Chen , Alex Lemberg , Mateusz Nowak , Yuliy Izrailov , Jaehoon Chung , Dong Aisheng , Das Asutosh , Zhangfei Gao , Sahitya Tummala , Harjani Ritesh , Venu Byravarasu , Linus Walleij , Shawn Lin , Christoph Hellwig Subject: Re: [PATCH V13 00/10] mmc: Add Command Queue support Date: Thu, 16 Nov 2017 10:46:40 +0100 Message-id: <1716036.6EalJ2kXtr@amdc3058> User-Agent: KMail/4.13.3 (Linux/3.13.0-96-generic; KDE/4.13.3; x86_64; ; ) In-reply-to: <1509715220-31885-1-git-send-email-adrian.hunter@intel.com> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset="us-ascii" X-Brightmail-Tracker: H4sIAAAAAAAAA02Se0hTYRjG+87ZOTuai9PUetGyWhdxpnbno1IKIg4aFVQUg9JhB5O8rB0N jSCtWCFpmVm2xEZF4dLEbTkv89LUplZmSpGRFTroYhl4yUtauR0D//vxvc/D+7wPH0PKuyg/ Jj4phdcmqRMUtKekojEoJOTcEZlqzVMj4FZnCY27P43RuFbXIsVT5hs0vvy6GOHih80Efjuh o/C1yQcErn0XjLuqC2nc9PcywpljPQSu7++g8HtnGYVfWYak2FF6EPfac0lsz2+h8dkHH4ht 3lxXTjbBVel7pNxd21eCe//GRnM13Rk0l31ugObKByoJbkpfL+FyLEbEXS95SXBDpoC9c1We W4/yCfEneW1YRIznsc+5zySaYSbNXFFPZ6A8aRbyYIDdAD/6i9wsZysRfJ9MyUKe0zyKYFBf Sv0X2WwFhDioQfB4ooUWHSMI8rMCXUyzmyH3ghG52IcNhrxJI+kykGwvBS/6ignXwJsNh3ut PW6zhF0JI1dz3Cxjg8BqOO/e5stGgqXuglvvwXLQ1mGSiJr5MJb3wc0kuwTq6vMpkVfDi6eP kGsZsHVS+NbRTIqxd4BlonCGveGbwzJ9JzPN/tDZHC4+30Bg/Q2i14zAWHNlppct0Oh4NbNg HgyMXKJErwwu6uSihIOqPsNMQ9vB9LedFhu6heC+00pfQYv1s3LrZ+XWz8ptQKQRLeA1QmIc L6zVrAsV1IlCalJcaGxyogm5v5pyUyW6077LjlgGKbxkHdFeKjmlPimkJ9oRMKTCR/Z4j0wl lx1Vp5/itcnR2tQEXrAjf0aiWCjzLXtzSM7GqVP44zyv4bX/pwTj4ZeB7CNPAjZGVTfsGDL7 Gxsk4/HXb+4e9m3s/tPpEYr7ywvSVmXqiTO3fSPHmzSGlysXxy6N85JPfRzKnqNcEWHcv7xT GRr4PebhlwnVaGGbn/N0v1AUM1kavvPAnxDHekt7xd5Uw68oKNv3vPnjoFU4sejnc5XuWkFY GxrXLVM65IcVEuGYeq2S1Arqf5iQiqNmAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrDIsWRmVeSWpSXmKPExsVy+t9jAd2mON4og9NN5hYnn6xhs7j54Aeb xd62E+wWfzdPZ7Pov7qS0WLl6qNMFjd+tbFaTPmznMli7y1ti8u75rBZHPnfz2jR+OMuk8X+ 1xdYLe48Wc9qcXHLZ3aL42vDLR4dmshscWjqCTaLpuX3mByEPS739TJ57Jx1l91j8Z6XTB53 ru1h89h9s4HNo7f5HZvHxnc7mDz+ztrP4tG3ZRWjx7Q155k8Pm+SC+CO4rJJSc3JLEst0rdL 4Mp4PvE0S8EXjorN2/azNTBOZu9i5OSQEDCR2LNnBlMXIxeHkMBORoknv2+zgCSEBL4ySixc VAViswlYSUxsX8UIYosIaEtM/rOKGaSBWeAFq8TZnv9MIAlhAVuJJSfvsoHYLAKqEl8n9YHZ vAKaEtsXtLCC2KICXhJb9rWD1XMKeEicurAJapm7xNWdh6HqBSV+TL4HFmcWkJfYt38qK4St JbF+53GmCYz8s5CUzUJSNgtJ2QJG5lWMkqkFxbnpucVGBYZ5qeV6xYm5xaV56XrJ+bmbGIFx uO2wVt8OxvtL4g8xCnAwKvHwaiTxRAmxJpYVV+YeYpTgYFYS4d3qzxslxJuSWFmVWpQfX1Sa k1p8iFGag0VJnPd23rFIIYH0xJLU7NTUgtQimCwTB6dUA6N95wz1zk3hggvOz5gcoKS3VaCH NYnV7M+MHHan0nrbp1dvdHBt6op4rMyudWinE28B3w2epvMuBl8zfRxq5mzSO+4rr8K7M5p1 Rf/jGP1rre8VK2xXdlx47ZQ58f23qJTyu5mxH7jqp6Z27/qiuvf2wq2GGR3f2F7fzBQpCbPk OVnuXpN5VomlOCPRUIu5qDgRAATuqRe/AgAA X-CMS-MailID: 20171116094642epcas1p14018cb1c475efa38942109dc24cd6da9 X-Msg-Generator: CA CMS-TYPE: 101P X-CMS-RootMailID: 20171116094642epcas1p14018cb1c475efa38942109dc24cd6da9 X-RootMTR: 20171116094642epcas1p14018cb1c475efa38942109dc24cd6da9 References: <1509715220-31885-1-git-send-email-adrian.hunter@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, November 03, 2017 03:20:10 PM Adrian Hunter wrote: > Hi > > Here is V13 of the hardware command queue patches without the software > command queue patches, now using blk-mq and now with blk-mq support for > non-CQE I/O. > > HW CMDQ offers 25% - 50% better random multi-threaded I/O. I see a slight > 2% drop in sequential read speed but no change to sequential write. > > Non-CQE blk-mq showed a 3% decrease in sequential read performance. This > seemed to be coming from the inferior latency of running work items compared > with a dedicated thread. Hacking blk-mq workqueue to be unbound reduced the > performance degradation from 3% to 1%. > > While we should look at changing blk-mq to give better workqueue performance, > a bigger gain is likely to be made by adding a new host API to enable the > next already-prepared request to be issued directly from within ->done() > callback of the current request. Tested-by: Bartlomiej Zolnierkiewicz [ for non-CQE changes ] Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics