[PATCH] PM: domains: Move genpd's time-accounting to ktime_get_mono_fast_ns()
Ulf Hansson
ulf.hansson at linaro.org
Tue Apr 19 10:29:16 PDT 2022
To move towards a more consistent behaviour between genpd and the runtime
PM core, let's start by converting genpd's time-accounting from ktime_get()
into ktime_get_mono_fast_ns().
Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
---
drivers/base/power/domain.c | 77 +++++++++++++++++++++----------------
include/linux/pm_domain.h | 6 +--
2 files changed, 46 insertions(+), 37 deletions(-)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 1ee878d126fd..18cd7965e5d6 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -225,24 +225,23 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd)
static void genpd_update_accounting(struct generic_pm_domain *genpd)
{
- ktime_t delta, now;
+ u64 delta, now;
- now = ktime_get();
- delta = ktime_sub(now, genpd->accounting_time);
+ now = ktime_get_mono_fast_ns();
+ if (now <= genpd->accounting_time)
+ return;
+
+ delta = now - genpd->accounting_time;
/*
* If genpd->status is active, it means we are just
* out of off and so update the idle time and vice
* versa.
*/
- if (genpd->status == GENPD_STATE_ON) {
- int state_idx = genpd->state_idx;
-
- genpd->states[state_idx].idle_time =
- ktime_add(genpd->states[state_idx].idle_time, delta);
- } else {
- genpd->on_time = ktime_add(genpd->on_time, delta);
- }
+ if (genpd->status == GENPD_STATE_ON)
+ genpd->states[genpd->state_idx].idle_time += delta;
+ else
+ genpd->on_time += delta;
genpd->accounting_time = now;
}
@@ -1999,7 +1998,7 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
genpd->max_off_time_changed = true;
genpd->provider = NULL;
genpd->has_provider = false;
- genpd->accounting_time = ktime_get();
+ genpd->accounting_time = ktime_get_mono_fast_ns();
genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
genpd->domain.ops.runtime_resume = genpd_runtime_resume;
genpd->domain.ops.prepare = genpd_prepare;
@@ -3163,6 +3162,7 @@ static int sub_domains_show(struct seq_file *s, void *data)
static int idle_states_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
+ u64 now, delta, idle_time = 0;
unsigned int i;
int ret = 0;
@@ -3173,17 +3173,19 @@ static int idle_states_show(struct seq_file *s, void *data)
seq_puts(s, "State Time Spent(ms) Usage Rejected\n");
for (i = 0; i < genpd->state_count; i++) {
- ktime_t delta = 0;
- s64 msecs;
+ idle_time += genpd->states[i].idle_time;
- if ((genpd->status == GENPD_STATE_OFF) &&
- (genpd->state_idx == i))
- delta = ktime_sub(ktime_get(), genpd->accounting_time);
+ if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
+ now = ktime_get_mono_fast_ns();
+ if (now > genpd->accounting_time) {
+ delta = now - genpd->accounting_time;
+ idle_time += delta;
+ }
+ }
- msecs = ktime_to_ms(
- ktime_add(genpd->states[i].idle_time, delta));
- seq_printf(s, "S%-13i %-14lld %-14llu %llu\n", i, msecs,
- genpd->states[i].usage, genpd->states[i].rejected);
+ do_div(idle_time, NSEC_PER_MSEC);
+ seq_printf(s, "S%-13i %-14llu %-14llu %llu\n", i, idle_time,
+ genpd->states[i].usage, genpd->states[i].rejected);
}
genpd_unlock(genpd);
@@ -3193,18 +3195,22 @@ static int idle_states_show(struct seq_file *s, void *data)
static int active_time_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
- ktime_t delta = 0;
+ u64 now, on_time, delta = 0;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
- if (genpd->status == GENPD_STATE_ON)
- delta = ktime_sub(ktime_get(), genpd->accounting_time);
+ if (genpd->status == GENPD_STATE_ON) {
+ now = ktime_get_mono_fast_ns();
+ if (now > genpd->accounting_time)
+ delta = now - genpd->accounting_time;
+ }
- seq_printf(s, "%lld ms\n", ktime_to_ms(
- ktime_add(genpd->on_time, delta)));
+ on_time = genpd->on_time + delta;
+ do_div(on_time, NSEC_PER_MSEC);
+ seq_printf(s, "%llu ms\n", on_time);
genpd_unlock(genpd);
return ret;
@@ -3213,7 +3219,7 @@ static int active_time_show(struct seq_file *s, void *data)
static int total_idle_time_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
- ktime_t delta = 0, total = 0;
+ u64 now, delta, total = 0;
unsigned int i;
int ret = 0;
@@ -3222,16 +3228,19 @@ static int total_idle_time_show(struct seq_file *s, void *data)
return -ERESTARTSYS;
for (i = 0; i < genpd->state_count; i++) {
+ total += genpd->states[i].idle_time;
- if ((genpd->status == GENPD_STATE_OFF) &&
- (genpd->state_idx == i))
- delta = ktime_sub(ktime_get(), genpd->accounting_time);
-
- total = ktime_add(total, genpd->states[i].idle_time);
+ if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
+ now = ktime_get_mono_fast_ns();
+ if (now > genpd->accounting_time) {
+ delta = now - genpd->accounting_time;
+ total += delta;
+ }
+ }
}
- total = ktime_add(total, delta);
- seq_printf(s, "%lld ms\n", ktime_to_ms(total));
+ do_div(total, NSEC_PER_MSEC);
+ seq_printf(s, "%llu ms\n", total);
genpd_unlock(genpd);
return ret;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 67017c9390c8..043d48e4420a 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -98,7 +98,7 @@ struct genpd_power_state {
u64 usage;
u64 rejected;
struct fwnode_handle *fwnode;
- ktime_t idle_time;
+ u64 idle_time;
void *data;
};
@@ -149,8 +149,8 @@ struct generic_pm_domain {
unsigned int state_count);
unsigned int state_count; /* number of states */
unsigned int state_idx; /* state that genpd will go to when off */
- ktime_t on_time;
- ktime_t accounting_time;
+ u64 on_time;
+ u64 accounting_time;
const struct genpd_lock_ops *lock_ops;
union {
struct mutex mlock;
--
2.25.1
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