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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 55EEDC433B4 for ; Tue, 6 Apr 2021 04:38:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24E8C61394 for ; Tue, 6 Apr 2021 04:38:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243593AbhDFEiM (ORCPT ); Tue, 6 Apr 2021 00:38:12 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:62394 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233796AbhDFEiL (ORCPT ); Tue, 6 Apr 2021 00:38:11 -0400 Received: from epcas3p2.samsung.com (unknown [182.195.41.20]) by mailout2.samsung.com (KnoxPortal) with ESMTP id 20210406043802epoutp02ece21b1b5deea602196cd826402386f4~zKuuOXi5W0198901989epoutp02g for ; Tue, 6 Apr 2021 04:38:02 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.samsung.com 20210406043802epoutp02ece21b1b5deea602196cd826402386f4~zKuuOXi5W0198901989epoutp02g DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1617683882; bh=cluGM44R5WOQaZ+AAkjY1huKsxNJn1WDAGgg6GaO4zs=; h=Subject:Reply-To:From:To:CC:In-Reply-To:Date:References:From; b=LbO1CICzEwMrSnosRIGP6Oj5iFQvFj5xik229J/uYnTPSbniqcZ3J1GqzoVp+1Xyt q9+NK/sejpMDO0K5NhwoxoA/BAYI2pjEIkHBlmz4vaweahFOvC1rDzICnLEWtMaD2s aPZHxctxs/SsBX5VHVkW4TD2i7YakTXyKMaxyzMk= Received: from epsnrtp4.localdomain (unknown [182.195.42.165]) by epcas3p2.samsung.com (KnoxPortal) with ESMTP id 20210406043801epcas3p214f94096eb26a1fe7bf2a7ee7ccd537a~zKutmJl3O0726507265epcas3p2R; Tue, 6 Apr 2021 04:38:01 +0000 (GMT) Received: from epcpadp4 (unknown [182.195.40.18]) by epsnrtp4.localdomain (Postfix) with ESMTP id 4FDvsP4W9vz4x9QF; Tue, 6 Apr 2021 04:38:01 +0000 (GMT) Mime-Version: 1.0 Subject: RE: [PATCH 1/2] scsi: ufs: Introduce hba performance monitor sysfs nodes Reply-To: daejun7.park@samsung.com Sender: Daejun Park From: Daejun Park To: "asutoshd@codeaurora.org" , "nguyenb@codeaurora.org" , "hongwus@codeaurora.org" , "linux-scsi@vger.kernel.org" , "kernel-team@android.com" , "cang@codeaurora.org" CC: ALIM AKHTAR , Avri Altman , "James E.J. Bottomley" , "Martin K. Petersen" , Stanley Chu , Bean Huo , Jaegeuk Kim , Adrian Hunter , Kiwoong Kim , Satya Tangirala , open list X-Priority: 3 X-Content-Kind-Code: NORMAL In-Reply-To: <1617257704-1154-2-git-send-email-cang@codeaurora.org> X-CPGS-Detection: blocking_info_exchange X-Drm-Type: N,general X-Msg-Generator: Mail X-Msg-Type: PERSONAL X-Reply-Demand: N Message-ID: <1891546521.01617683881598.JavaMail.epsvc@epcpadp4> Date: Tue, 06 Apr 2021 13:11:40 +0900 X-CMS-MailID: 20210406041140epcms2p5a717b30f522bd99c8b3c805397a73692 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: AUTO_CONFIDENTIAL X-CPGSPASS: Y X-CPGSPASS: Y X-Hop-Count: 3 X-CMS-RootMailID: 20210401061611epcas2p279c9303e0e0bf4e2bc5eb1f4ffd84c52 References: <1617257704-1154-2-git-send-email-cang@codeaurora.org> <1617257704-1154-1-git-send-email-cang@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Can Guo, > +static ssize_t monitor_enable_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct ufs_hba *hba = dev_get_drvdata(dev); > + unsigned long value, flags; > + > + if (kstrtoul(buf, 0, &value)) > + return -EINVAL; > + > + value = !!value; > + spin_lock_irqsave(hba->host->host_lock, flags); > + if (value == hba->monitor.enabled) > + goto out_unlock; > + > + if (!value) { > + memset(&hba->monitor, 0, sizeof(hba->monitor)); > + } else { > + hba->monitor.enabled = true; > + hba->monitor.enabled_ts = ktime_get(); How about setting lat_max to and lat_min to KTIME_MAX and 0? I think lat_sum should be 0 at this point. > + } > + > +out_unlock: > + spin_unlock_irqrestore(hba->host->host_lock, flags); > + return count; > +} > +static void ufshcd_update_monitor(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) > +{ > + int dir = ufshcd_monitor_opcode2dir(*lrbp->cmd->cmnd); > + > + if (dir >= 0 && hba->monitor.nr_queued[dir] > 0) { > + struct request *req = lrbp->cmd->request; > + struct ufs_hba_monitor *m = &hba->monitor; > + ktime_t now, inc, lat; > + > + now = ktime_get(); How about using lrbp->compl_time_stamp instead of getting new value? > + inc = ktime_sub(now, m->busy_start_ts[dir]); > + m->total_busy[dir] = ktime_add(m->total_busy[dir], inc); > + m->nr_sec_rw[dir] += blk_rq_sectors(req); > + > + /* Update latencies */ > + m->nr_req[dir]++; > + lat = ktime_sub(now, lrbp->issue_time_stamp); > + m->lat_sum[dir] += lat; > + if (m->lat_max[dir] < lat || !m->lat_max[dir]) > + m->lat_max[dir] = lat; > + if (m->lat_min[dir] > lat || !m->lat_min[dir]) > + m->lat_min[dir] = lat; This if statement can be shorted, by setting lat_max / lat_min as default value. > + > + m->nr_queued[dir]--; > + /* Push forward the busy start of monitor */ > + m->busy_start_ts[dir] = now; > + } > +} Thanks, Daejun