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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 5FF4DC43381 for ; Thu, 14 Feb 2019 11:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A616222B6 for ; Thu, 14 Feb 2019 11:22:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405696AbfBNLWg (ORCPT ); Thu, 14 Feb 2019 06:22:36 -0500 Received: from 61-228-47-100.dynamic-ip.hinet.net ([61.228.47.100]:48744 "EHLO E6440.gar.corp.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1733036AbfBNLWg (ORCPT ); Thu, 14 Feb 2019 06:22:36 -0500 Received: from E6440.gar.corp.intel.com (localhost [127.0.0.1]) by E6440.gar.corp.intel.com (Postfix) with ESMTP id F1018C0680; Thu, 14 Feb 2019 15:16:56 +0800 (CST) From: Harry Pan To: LKML Cc: gs0622@gmail.com, Harry Pan , rjw@rjwysocki.net, len.brown@intel.com, pavel@ucw.cz, linux-pm@vger.kernel.org Subject: [PATCH v3] PM / suspend: measure the time of filesystem syncing Date: Thu, 14 Feb 2019 15:16:51 +0800 Message-Id: <20190214071651.447-1-harry.pan@intel.com> X-Mailer: git-send-email 2.18.1 In-Reply-To: <20190206154214.576-1-harry.pan@intel.com> References: <20190206154214.576-1-harry.pan@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch gives the reader an intuitive metric of the time cost by the kernel issuing a filesystem sync during suspend; although developer can guess by the timestamp of next log or enable the ftrace power event for manual calculation, this manner is easier to read and benefits the automatic script. v2: simplify the variables, apply the simplest form of ktime API. v3: reduce conditional compilation, rectify profiling in better syntax Signed-off-by: Harry Pan --- kernel/power/suspend.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 0bd595a0b610..4844fc6a796d 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -568,13 +568,20 @@ static int enter_state(suspend_state_t state) if (state == PM_SUSPEND_TO_IDLE) s2idle_begin(); -#ifndef CONFIG_SUSPEND_SKIP_SYNC - trace_suspend_resume(TPS("sync_filesystems"), 0, true); - pr_info("Syncing filesystems ... "); - ksys_sync(); - pr_cont("done.\n"); - trace_suspend_resume(TPS("sync_filesystems"), 0, false); -#endif + if (!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC)) { + ktime_t start; + unsigned int elapsed_msecs; + + trace_suspend_resume(TPS("sync_filesystems"), 0, true); + pr_info("Syncing filesystems ... "); + start = ktime_get(); + ksys_sync(); + elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start)); + pr_cont("(elapsed %d.%03d seconds) done.\n", + elapsed_msecs / MSEC_PER_SEC, + elapsed_msecs % MSEC_PER_SEC); + trace_suspend_resume(TPS("sync_filesystems"), 0, false); + } pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]); pm_suspend_clear_flags(); -- 2.18.1