From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Harry Pan <harry.pan@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
gs0622@gmail.com, pavel@ucw.cz, len.brown@intel.com,
linux-pm@vger.kernel.org
Subject: Re: [PATCH] PM / suspend: measure the time of filesystem syncing
Date: Tue, 05 Feb 2019 12:55:01 +0100 [thread overview]
Message-ID: <1702604.tyfAVjpQ0o@aspire.rjw.lan> (raw)
In-Reply-To: <20190203052007.27392-1-harry.pan@intel.com>
On Sunday, February 3, 2019 6:20:07 AM CET Harry Pan wrote:
> 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.
>
> Signed-off-by: Harry Pan <harry.pan@intel.com>
> ---
> kernel/power/suspend.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> index 0bd595a0b610..f3b7c64f2242 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, end, elapsed;
Why do you need three vars here? One should be sufficient.
> + unsigned int elapsed_msecs;
>
> trace_suspend_resume(TPS("suspend_enter"), state, true);
> if (state == PM_SUSPEND_TO_IDLE) {
> @@ -570,9 +572,14 @@ static int enter_state(suspend_state_t state)
>
> #ifndef CONFIG_SUSPEND_SKIP_SYNC
> trace_suspend_resume(TPS("sync_filesystems"), 0, true);
> + start = ktime_get_boottime();
Why _boottime()?
> pr_info("Syncing filesystems ... ");
> ksys_sync();
> - pr_cont("done.\n");
> + end = ktime_get_boottime();
> + elapsed = ktime_sub(end, start);
> + elapsed_msecs = ktime_to_ms(elapsed);
> + pr_cont("(elapsed %d.%03d seconds) done.\n", elapsed_msecs / 1000,
> + elapsed_msecs % 1000);
> trace_suspend_resume(TPS("sync_filesystems"), 0, false);
> #endif
>
>
next prev parent reply other threads:[~2019-02-05 11:56 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-03 5:20 [PATCH] PM / suspend: measure the time of filesystem syncing Harry Pan
2019-02-05 11:55 ` Rafael J. Wysocki [this message]
2019-02-06 14:52 ` Pan, Harry
2019-02-05 21:23 ` Pavel Machek
2019-02-06 15:08 ` Pan, Harry
2019-02-06 15:31 ` Pan, Harry
2019-02-06 16:16 ` Pavel Machek
2019-02-12 0:40 ` Pan, Harry
2019-02-06 14:42 ` Harry Pan
2019-02-06 14:53 ` Pavel Machek
2019-02-12 23:21 ` Rafael J. Wysocki
2019-02-12 23:26 ` Rafael J. Wysocki
2019-02-12 23:35 ` Rafael J. Wysocki
2019-02-06 15:42 ` [PATCH v2] " Harry Pan
2019-02-14 7:16 ` [PATCH v3] " Harry Pan
2019-02-14 11:15 ` Harry Pan
2019-02-19 10:24 ` Rafael J. Wysocki
2019-02-20 16:44 ` Pan, Harry
2019-02-20 21:45 ` Rafael J. Wysocki
2019-02-22 15:56 ` Pan, Harry
2019-02-20 16:12 ` [PATCH v4] " Harry Pan
2019-02-20 16:18 ` Harry Pan
2019-02-22 14:54 ` [PATCH v5] PM / sleep: " Harry Pan
2019-02-24 19:37 ` kbuild test robot
2019-02-24 23:23 ` kbuild test robot
2019-02-22 15:49 ` Harry Pan
2019-02-22 17:54 ` Pavel Machek
2019-02-24 6:17 ` [PATCH v6 1/2] PM / sleep: refactor the filesystems sync to reduce duplication Harry Pan
2019-02-24 6:17 ` [PATCH v6 2/2] PM / sleep: measure the time of filesystems syncing Harry Pan
2019-02-24 20:30 ` kbuild test robot
2019-02-24 21:51 ` kbuild test robot
2019-02-25 9:44 ` [PATCH v7 1/2] PM / sleep: refactor the filesystems sync to reduce duplication Harry Pan
2019-02-25 9:44 ` [PATCH v7 2/2] PM / sleep: measure the time of filesystems syncing Harry Pan
2019-02-25 12:36 ` [PATCH v7 1/2] PM / sleep: refactor the filesystems sync to reduce duplication Harry Pan
2019-02-25 12:36 ` [PATCH v7 2/2] PM / sleep: measure the time of filesystems syncing Harry Pan
2019-03-22 8:21 ` [PATCH v7 1/2] PM / sleep: refactor the filesystems sync to reduce duplication Pavel Machek
2019-02-25 7:33 ` [PATCH v5] PM / sleep: measure the time of filesystem syncing kbuild test robot
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