diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-01-13 19:41:55 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-01-20 17:16:45 +0100 |
| commit | e24f8a55de509ba26726f094e084d90428cbcf26 (patch) | |
| tree | 6715ca49e449c15560eb1c54f01c3d928629d27a /drivers/cpuidle/governors | |
| parent | b9a6af26bd83fb23d15c53b1ce63df77dda15513 (diff) | |
cpuidle: teo: Clarify two code comments
Rewrite two code comments suposed to explain its behavior that are too
concise or not sufficiently clear.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Tested-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/8472971.T7Z3S40VBb@rjwysocki.net
[ rjw: Fixed 2 typos in new comments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle/governors')
| -rw-r--r-- | drivers/cpuidle/governors/teo.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c index 95d76c8e0d12..411b315081f8 100644 --- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -154,9 +154,10 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) if (cpu_data->time_span_ns >= cpu_data->sleep_length_ns) { /* - * One of the safety nets has triggered or the wakeup was close - * enough to the closest timer event expected at the idle state - * selection time to be discarded. + * This causes the wakeup to be counted as a hit regardless of + * the real idle duration which doesn't need to be computed + * because the wakeup has been close enough to an anticipated + * timer. */ measured_ns = U64_MAX; } else { @@ -302,8 +303,13 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, cpu_data->time_span_ns = local_clock(); /* - * Set the expected sleep length to infinity in case of an early - * return. + * Set the sleep length to infinity in case the invocation of + * tick_nohz_get_sleep_length() below is skipped, in which case it won't + * be known whether or not the subsequent wakeup is caused by a timer. + * It is generally fine to count the wakeup as an intercept then, except + * for the cases when the CPU is mostly woken up by timers and there may + * be opportunities to ask for a deeper idle state when no imminent + * timers are scheduled which may be missed. */ cpu_data->sleep_length_ns = KTIME_MAX; |