Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH v3] PM / suspend: measure the time of filesystem syncing | Date | Tue, 19 Feb 2019 11:24:36 +0100 |
| |
On Thursday, February 14, 2019 12:15:43 PM 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. > > 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 <harry.pan@intel.com> > --- > 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);
One more nit.
Since you are printing the sync time anyway, there is a little sense to split the message using pr_cont() that may be messed up with by any intervening messages, so why don't you just print a one-line pr_info("Filesystems sync: %d.%03d seconds\n", ...) message?
Also, if you change it here, I guess it would be consistent to make an analogous change for hibernation.
> + 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(); >
| |