On Sat, Jun 06, 2020 at 03:05:52AM +0800, Chen Yu wrote:
> 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.
[...]
> @@ -1448,16 +1453,17 @@ 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);
> -
[...]
IIRC, rpm_idle() has a tracepoint already.
> @@ -1523,9 +1529,8 @@ 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);
> }
> }
[...]
This actually changes logic, so it doesn't match the patch description.
Best Regards
Michał Mirosław
