Re: [patch 15/16] cpufreq: intel-pstate: Use del_timer_sync in intel_pstate_cpu_exit()

[Dirk Brandewie]

Hi Thomas,
On 03/23/2014 06:56 PM, Rafael J. Wysocki wrote:
> On Sunday, March 23, 2014 03:09:32 PM Thomas Gleixner wrote:
> > We are about to free the data structure. Make sure no timer callback
> > is running. I might be paranoid, but the ->exit callback can be
> > invoked from so many places, that it is not entirely clear whether
> > del_timer is always called on the cpu on which it is enqueued.
> >
> > While looking through the call sites I noticed, that
> > cpufreq_init_policy() can fail and invoke cpufreq_driver->exit() but
> > it does not return the failure and the callsite happily proceeds.

The call to del_timer() has been moved to a new callback in material
in Rafaels pull request for v3.15.

I will send a patch adding this change to the v3.15 material.

--Dirk
> > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> > Cc: cpufreq <cpufreq@xxxxxxxxxxxxxxx>
> > Cc: pm <linux-pm@xxxxxxxxxxxxxxx>
>
> Dirk?
>
> > ---
> >
> >   drivers/cpufreq/intel_pstate.c |    2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Index: tip/drivers/cpufreq/intel_pstate.c
> > ===================================================================
> > --- tip.orig/drivers/cpufreq/intel_pstate.c
> > +++ tip/drivers/cpufreq/intel_pstate.c
> > @@ -777,7 +777,7 @@ static int intel_pstate_cpu_exit(struct
> >   {
> >   	int cpu = policy->cpu;
> >
> > -	del_timer(&all_cpu_data[cpu]->timer);
> > +	del_timer_sync(&all_cpu_data[cpu]->timer);
> >   	kfree(all_cpu_data[cpu]);
> >   	all_cpu_data[cpu] = NULL;
> >   	return 0;

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