Messages in this thread | | | Date | Wed, 15 Jul 2020 09:06:14 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH 2/2][RESEND v3] PM-runtime: change the tracepoints to cover all usage_count |
| |
On Wed, Jul 15, 2020 at 02:28:03PM +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 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. > > Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > --- > 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);
Why not just call trace everywhere before you do the atomic operations? Why does the trace need to be called after the operation everywhere?
thanks,
greg k-h
| |