From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93077C64E69 for ; Wed, 18 Nov 2020 00:48:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E49924181 for ; Wed, 18 Nov 2020 00:48:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LgyAURrt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726411AbgKRArx (ORCPT ); Tue, 17 Nov 2020 19:47:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725767AbgKRArx (ORCPT ); Tue, 17 Nov 2020 19:47:53 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDDF4C061A48 for ; Tue, 17 Nov 2020 16:47:51 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id w14so309494pfd.7 for ; Tue, 17 Nov 2020 16:47:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=xjik3bPj3QD7dVsokOhUZfPJKy6Jis8hViC/+zvOQUM=; b=LgyAURrtaY4pITG+veedMmuKbamN9sFy7cybnlGk8m4IWvoWE6/jPnxmCtdNdHheib 001vrHiofXWnYk+yb+VEmfWJrcONgi22lEHl+LQYsWpceSLSKECYVoF1aoVZA0//cWEg TIaubHoKp9PNl8Sretrb+5J5Rq2txAtQ4YP9LmbYhGhq/noEL+45JU0gbiQ+REcte2Fx DVzpeYQ/tzWl0mbSBZK25VeeYizlf1Ps4Un/X+MIz3/UTaF84gFEJI0zWZIP3arkIWd/ xfXJboO9/bw6PORTD2WB/8rR4WxcvYVfk960F4ROWyiD+I9RwOdWAwQ1EWdglXK2r12z 8LwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=xjik3bPj3QD7dVsokOhUZfPJKy6Jis8hViC/+zvOQUM=; b=j8kKM1UlQvei9pUyeizpS+oWZr2H5Es4o3DgFMCtA2fl3mM28r8X4BFX8tB/ayAhE+ bQwNqXCVXWrPwe8t2EN4Y3dGhZSRgVvlgmjxBzuTcLeYZHvMdTTzjLrFJwyvVWPCCeMH q5x1AULzz91yrKjm62R1oN2FNdskNLAQf+55KJOl+HpInd7ap0i2reRI5TCU2PZAN4tk auUuabD+ZO8ACy7gQ14OXLMh9PZRV9/YGHzis59cTFRgG8LWl/VD3HM1NPKxCGDf/Os3 TahwbN66qiliN2u3xKOxpAbySyFldJChpfXznpd6ZtEHhjmY8oKqaf7S9o3kfSNaJA57 8vzw== X-Gm-Message-State: AOAM533rBnfmO20L/bxnF+D8PSCy+3kJaODtvdz8r0aio6hc72YDtLBH h0vxZqSd6IZ8Zmq7jRl/qiSa+QpTVle55XtE X-Google-Smtp-Source: ABdhPJxZaJs674HlDlcgpHYSZtLoB+BQV7xXZC0KRKiWQP0CIKgbkZ691qPGW617771aWNtHMZ2/UA== X-Received: by 2002:a63:389:: with SMTP id 131mr5857528pgd.128.1605660471417; Tue, 17 Nov 2020 16:47:51 -0800 (PST) Received: from dongjoo-desktop ([203.246.112.155]) by smtp.gmail.com with ESMTPSA id q14sm20992368pfl.163.2020.11.17.16.47.49 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 17 Nov 2020 16:47:50 -0800 (PST) Date: Wed, 18 Nov 2020 09:47:46 +0900 From: Dongjoo Seo To: axboe@kernel.dk, hch@infradead.org, ming.lei@redhat.com Cc: linux-block@vger.kernel.org Subject: [PATCH] blk-mq: modify hybrid sleep time to aggressive Message-ID: <20201118004746.GA29180@dongjoo-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Current sleep time for hybrid polling is half of mean time. The 'half' sleep time is good for minimizing the cpu utilization. But, the problem is that its cpu utilization is still high. this patch can help to minimize the cpu utilization side. Below 1,2 is my test hardware sets. 1. Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz + Samsung 970 pro 1Tb 2. Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz + INTEL SSDPED1D480GA 480G | Classic Polling | Hybrid Polling | this Patch ----------------------------------------------------------------- cpu util | IOPS(k) | cpu util | IOPS | cpu util | IOPS | ----------------------------------------------------------------- 1. 99.96 | 491 | 56.98 | 467 | 35.98 | 442 | ----------------------------------------------------------------- 2. 99.94 | 582 | 56.3 | 582 | 35.28 | 582 | cpu util means that sum of sys and user util. I used 4k rand read for this test. because that case is worst case of I/O performance side. below one is my fio setup. name=pollTest ioengine=pvsync2 hipri direct=1 size=100% randrepeat=0 time_based ramp_time=0 norandommap refill_buffers log_avg_msec=1000 log_max_value=1 group_reporting filename=/dev/nvme0n1 [rd_rnd_qd_1_4k_1w] bs=4k iodepth=32 numjobs=[num of cpus] rw=randread runtime=60 write_bw_log=bw_rd_rnd_qd_1_4k_1w write_iops_log=iops_rd_rnd_qd_1_4k_1w write_lat_log=lat_rd_rnd_qd_1_4k_1w Thanks Signed-off-by: Dongjoo Seo --- block/blk-mq.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 1b25ec2fe9be..c3d578416899 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3749,8 +3749,7 @@ static unsigned long blk_mq_poll_nsecs(struct request_queue *q, return ret; if (q->poll_stat[bucket].nr_samples) - ret = (q->poll_stat[bucket].mean + 1) / 2; - + ret = (q->poll_stat[bucket].mean + 1) * 3 / 4; return ret; } -- 2.17.1