On Tue, 2016-03-22 at 08:21 +0530, Viresh Kumar wrote:
> On 22-03-16, 01:17, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> >
> > Modify dbs_irq_work() to always schedule the process-context work
> > on the current CPU which also ran the dbs_update_util_handler()
> > that the irq_work being handled came from.
> >
> > This causes the entire frequency update handling (involving the
> > "ondemand" or "conservative" governors) to be carried out by the
> > CPU whose frequency is to be updated and reduces the overall amount
> > of inter-CPU noise related to cpufreq.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> > ---
> > drivers/cpufreq/cpufreq_governor.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
> > ===================================================================
> > --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
> > +++ linux-pm/drivers/cpufreq/cpufreq_governor.c
> > @@ -245,7 +245,7 @@ static void dbs_irq_work(struct irq_work
> > struct policy_dbs_info *policy_dbs;
> >
> > policy_dbs = container_of(irq_work,
> > structwq_unbound_cpumask policy_dbs_info, irq_work);
> > - schedule_work(&policy_dbs->work);
> > + schedule_work_on(smp_processor_id(), &policy_dbs->work);
> > }
> >
> > static void dbs_update_util_handler(struct update_util_data *data,
> > u64 time,
>
> queue_work() used to queue the work on local cpu by default, has that
> changed now ?
By default it still will, but the user now has the option to deflect
work items with an unspecified target. These will land on a CPU
included in wq_unbound_cpumask iff the current CPU is excluded
therefrom.
-Mike
