Commit d229290689ae ("PM-runtime: add tracepoints for usage_count changes")
has added some tracepoints to monitor the change of runtime usage, and
there is something to improve:
1. There are some places that adjust the usage count have not
been traced yet. For example, pm_runtime_get_noresume() and
pm_runtime_put_noidle()
2. The change of the usage count will not be tracked if decreased
from 1 to 0.
This patch intends to adjust the logic to be consistent with the
change of usage_counter, that is to say, only after the counter has
been possibly modified, we record it. Besides, all usage changes will
be shown using rpm_usage even if included by other trace points.
And these changes has helped track down the e1000e runtime issue.
Signed-off-by: Chen Yu <[email protected]>
---
v2: According to Michal's suggestion, adjust the commit log
to better describe the meaning of this patch.
--
drivers/base/power/runtime.c | 38 +++++++++++++++++++++++-------------
1 file changed, 24 insertions(+), 14 deletions(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 85a248e196ca..5789d2624513 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1004,10 +1004,11 @@ int __pm_runtime_idle(struct device *dev, int rpmflags)
int retval;
if (rpmflags & RPM_GET_PUT) {
- if (!atomic_dec_and_test(&dev->power.usage_count)) {
- trace_rpm_usage_rcuidle(dev, rpmflags);
+ bool non_zero = !atomic_dec_and_test(&dev->power.usage_count);
+
+ trace_rpm_usage_rcuidle(dev, rpmflags);
+ if (non_zero)
return 0;
- }
}
might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
@@ -1038,10 +1039,12 @@ int __pm_runtime_suspend(struct device *dev, int
rpmflags)
int retval;
if (rpmflags & RPM_GET_PUT) {
- if (!atomic_dec_and_test(&dev->power.usage_count)) {
- trace_rpm_usage_rcuidle(dev, rpmflags);
+ bool non_zero = !atomic_dec_and_test(&dev->power.usage_count);
+
+ trace_rpm_usage_rcuidle(dev, rpmflags);
+ if (non_zero)
return 0;
- }
+
}
might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
@@ -1073,8 +1076,10 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe &&
dev->power.runtime_status != RPM_ACTIVE);
- if (rpmflags & RPM_GET_PUT)
+ if (rpmflags & RPM_GET_PUT) {
atomic_inc(&dev->power.usage_count);
+ trace_rpm_usage_rcuidle(dev, rpmflags);
+ }
spin_lock_irqsave(&dev->power.lock, flags);
retval = rpm_resume(dev, rpmflags);
@@ -1433,6 +1438,7 @@ void pm_runtime_forbid(struct device *dev)
dev->power.runtime_auto = false;
atomic_inc(&dev->power.usage_count);
+ trace_rpm_usage_rcuidle(dev, 0);
rpm_resume(dev, 0);
out:
@@ -1448,16 +1454,17 @@ EXPORT_SYMBOL_GPL(pm_runtime_forbid);
*/
void pm_runtime_allow(struct device *dev)
{
+ bool is_zero;
+
spin_lock_irq(&dev->power.lock);
if (dev->power.runtime_auto)
goto out;
dev->power.runtime_auto = true;
- if (atomic_dec_and_test(&dev->power.usage_count))
+ is_zero = atomic_dec_and_test(&dev->power.usage_count);
+ trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);
+ if (is_zero)
rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
- else
- trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);
-
out:
spin_unlock_irq(&dev->power.lock);
}
@@ -1523,9 +1530,8 @@ static void update_autosuspend(struct device *dev, int
old_delay, int old_use)
/* If it used to be allowed then prevent it. */
if (!old_use || old_delay >= 0) {
atomic_inc(&dev->power.usage_count);
- rpm_resume(dev, 0);
- } else {
trace_rpm_usage_rcuidle(dev, 0);
+ rpm_resume(dev, 0);
}
}
@@ -1533,8 +1539,10 @@ static void update_autosuspend(struct device *dev, int
old_delay, int old_use)
else {
/* If it used to be prevented then allow it. */
- if (old_use && old_delay < 0)
+ if (old_use && old_delay < 0) {
atomic_dec(&dev->power.usage_count);
+ trace_rpm_usage_rcuidle(dev, 0);
+ }
/* Maybe we can autosuspend now. */
rpm_idle(dev, RPM_AUTO);
@@ -1741,12 +1749,14 @@ void pm_runtime_drop_link(struct device *dev)
void pm_runtime_get_noresume(struct device *dev)
{
atomic_inc(&dev->power.usage_count);
+ trace_rpm_usage_rcuidle(dev, 0);
}
EXPORT_SYMBOL_GPL(pm_runtime_get_noresume);
void pm_runtime_put_noidle(struct device *dev)
{
atomic_add_unless(&dev->power.usage_count, -1, 0);
+ trace_rpm_usage_rcuidle(dev, 0);
}
EXPORT_SYMBOL_GPL(pm_runtime_put_noidle);
--
2.17.1
