lkml.org 
[lkml]   [2024]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2 3/3] thermal/debugfs: Avoid printing zero duration for mitigation events in progress
From


On 4/25/24 15:05, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> If a thermal mitigation event is in progress, its duration value has
> not been updated yet, so 0 will be printed as the event duration by
> tze_seq_show() which is confusing.
>
> Avoid doing that by marking the beginning of the event with the
> KTIME_MIN duration value and making tze_seq_show() compute the current
> event duration on the fly, in which case '>' will be printed instead of
> '=' in the event duration value field.
>
> Similarly, for trip points that have been crossed on the down, mark
> the end of mitigation with the KTIME_MAX timestamp value and make
> tze_seq_show() compute the current duration on the fly for the trip
> points still involved in the mitigation, in which cases the duration
> value printed by it will be prepended with a '>' character.
>
> Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/thermal/thermal_debugfs.c | 39 ++++++++++++++++++++++++++++++++------
> 1 file changed, 33 insertions(+), 6 deletions(-)
>
> Index: linux-pm/drivers/thermal/thermal_debugfs.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_debugfs.c
> +++ linux-pm/drivers/thermal/thermal_debugfs.c
> @@ -552,6 +552,7 @@ static struct tz_episode *thermal_debugf
>
> INIT_LIST_HEAD(&tze->node);
> tze->timestamp = now;
> + tze->duration = KTIME_MIN;
>
> for (i = 0; i < tz->num_trips; i++) {
> tze->trip_stats[i].min = INT_MAX;
> @@ -680,6 +681,9 @@ void thermal_debug_tz_trip_down(struct t
> tze->trip_stats[trip_id].duration =
> ktime_add(delta, tze->trip_stats[trip_id].duration);
>
> + /* Mark the end of mitigation for this trip point. */
> + tze->trip_stats[trip_id].timestamp = KTIME_MAX;
> +
> /*
> * This event closes the mitigation as we are crossing the
> * last trip point the way down.
> @@ -754,15 +758,25 @@ static int tze_seq_show(struct seq_file
> struct thermal_trip_desc *td;
> struct tz_episode *tze;
> const char *type;
> + u64 duration_ms;
> int trip_id;
> + char c;
>
> tze = list_entry((struct list_head *)v, struct tz_episode, node);
>
> - seq_printf(s, ",-Mitigation at %lluus, duration=%llums\n",
> - ktime_to_us(tze->timestamp),
> - ktime_to_ms(tze->duration));
> + if (tze->duration == KTIME_MIN) {
> + /* Mitigation in progress. */
> + duration_ms = ktime_to_ms(ktime_sub(ktime_get(), tze->timestamp));
> + c = '>';
> + } else {
> + duration_ms = ktime_to_ms(tze->duration);
> + c = '=';
> + }
> +
> + seq_printf(s, ",-Mitigation at %lluus, duration%c%llums\n",
> + ktime_to_us(tze->timestamp), c, duration_ms);
>
> - seq_printf(s, "| trip | type | temp(°mC) | hyst(°mC) | duration | avg(°mC) | min(°mC) | max(°mC) |\n");
> + seq_printf(s, "| trip | type | temp(°mC) | hyst(°mC) | duration | avg(°mC) | min(°mC) | max(°mC) |\n");

So this one more space accounts for the new 'c' symbol in the rows
below that header, for the 'duration' column. Make sense.

>
> for_each_trip_desc(tz, td) {
> const struct thermal_trip *trip = &td->trip;
> @@ -794,12 +808,25 @@ static int tze_seq_show(struct seq_file
> else
> type = "hot";
>
> - seq_printf(s, "| %*d | %*s | %*d | %*d | %*lld | %*d | %*d | %*d |\n",
> + if (trip_stats->timestamp != KTIME_MAX) {
> + /* Mitigation in progress. */
> + ktime_t delta = ktime_sub(ktime_get(),
> + trip_stats->timestamp);
> +
> + delta = ktime_add(delta, trip_stats->duration);
> + duration_ms = ktime_to_ms(delta);
> + c = '>';
> + } else {
> + duration_ms = ktime_to_ms(trip_stats->duration);
> + c = ' ';
> + }
> +
> + seq_printf(s, "| %*d | %*s | %*d | %*d | %c%*lld | %*d | %*d | %*d |\n",
> 4 , trip_id,
> 8, type,
> 9, trip->temperature,
> 9, trip->hysteresis,
> - 10, ktime_to_ms(trip_stats->duration),
> + c, 10, duration_ms,
> 9, trip_stats->avg,
> 9, trip_stats->min,
> 9, trip_stats->max);
>
>
>
>

The comments in code in this particular case helps, since treating
the KTIME_MIN/MAX values might become not obvious after a while.
That LGTM

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

\
 
 \ /
  Last update: 2024-05-27 18:04    [W:0.193 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site