From mboxrd@z Thu Jan 1 00:00:00 1970 From: Harry Pan Subject: [PATCH v6 2/2] PM / sleep: measure the time of filesystems syncing Date: Sun, 24 Feb 2019 14:17:54 +0800 Message-ID: <20190224061753.17638-2-harry.pan@intel.com> References: <20190222154904.6260-1-harry.pan@intel.com> <20190224061753.17638-1-harry.pan@intel.com> Return-path: In-Reply-To: <20190224061753.17638-1-harry.pan@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: LKML Cc: harry.pan@intel.com, gs0622@gmail.com, rjw@rjwysocki.net, pavel@ucw.cz, len.brown@intel.com, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org This patch gives the reader an intuitive metric of the time cost by the kernel issuing filesystems sync during system sleep; 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 automation script. Signed-off-by: Harry Pan --- kernel/power/main.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/power/main.c b/kernel/power/main.c index a8a8e6ec57e6..a08dcc743f31 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -54,9 +54,15 @@ EXPORT_SYMBOL_GPL(unlock_system_sleep); void ksys_sync_helper(void) { - pr_info("Syncing filesystems ... "); + ktime_t start; + s64 elapsed_msecs; + + start = ktime_get(); ksys_sync(); - pr_cont("done.\n"); + elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start)); + pr_info("Filesystems sync: %lld.%03lld seconds\n", + elapsed_msecs / MSEC_PER_SEC, + elapsed_msecs % MSEC_PER_SEC); } EXPORT_SYMBOL_GPL(ksys_sync_helper); -- 2.18.1