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 8B897C169C4 for ; Wed, 6 Feb 2019 15:57:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6513B218AD for ; Wed, 6 Feb 2019 15:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730606AbfBFP5f (ORCPT ); Wed, 6 Feb 2019 10:57:35 -0500 Received: from 36-231-43-191.dynamic-ip.hinet.net ([36.231.43.191]:58724 "EHLO E6440.gar.corp.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726989AbfBFP5d (ORCPT ); Wed, 6 Feb 2019 10:57:33 -0500 Received: from E6440.gar.corp.intel.com (localhost [127.0.0.1]) by E6440.gar.corp.intel.com (Postfix) with ESMTP id 863E4C04FD; Wed, 6 Feb 2019 22:43:00 +0800 (CST) From: Harry Pan To: LKML Cc: gs0622@gmail.com, Harry Pan , rjw@rjwysocki.net, pavel@ucw.cz, len.brown@intel.com, linux-pm@vger.kernel.org Subject: [PATCH] PM / suspend: measure the time of filesystem syncing Date: Wed, 6 Feb 2019 22:42:57 +0800 Message-Id: <20190206144257.21464-1-harry.pan@intel.com> X-Mailer: git-send-email 2.18.1 In-Reply-To: <20190203052007.27392-1-harry.pan@intel.com> References: <20190203052007.27392-1-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. Signed-off-by: Harry Pan --- kernel/power/suspend.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 0bd595a0b610..87c0073f0c9d 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -550,6 +550,8 @@ static void suspend_finish(void) static int enter_state(suspend_state_t state) { int error; + ktime_t start; + unsigned int elapsed_msecs; trace_suspend_resume(TPS("suspend_enter"), state, true); if (state == PM_SUSPEND_TO_IDLE) { @@ -570,9 +572,12 @@ static int enter_state(suspend_state_t state) #ifndef CONFIG_SUSPEND_SKIP_SYNC trace_suspend_resume(TPS("sync_filesystems"), 0, true); + start = ktime_get(); pr_info("Syncing filesystems ... "); ksys_sync(); - pr_cont("done.\n"); + elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start)); + pr_cont("(elapsed %d.%03d seconds) done.\n", elapsed_msecs / 1000, + elapsed_msecs % 1000); trace_suspend_resume(TPS("sync_filesystems"), 0, false); #endif -- 2.18.1