On Thu, Jun 25, 2020 at 7:14 AM Chen Yu <yu.c.c...@intel.com> wrote:
>
> Hi Rafael,
> On Tue, Jun 23, 2020 at 07:57:59PM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> > Subject: [PATCH] cpuidle: Rearrange s2idle-specific idle state entry code
> >
> > Implement call_cpuidle_s2idle() in analogy with call_cpuidle()
> > for the s2idle-specific idle state entry and invoke it from
> > cpuidle_idle_call() to make the s2idle-specific idle entry code
> > path look more similar to the "regular" idle entry one.
> >
> > No intentional functional impact.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> > ---
> > drivers/cpuidle/cpuidle.c | 6 +++---
> > kernel/sched/idle.c | 15 +++++++++++----
> > 2 files changed, 14 insertions(+), 7 deletions(-)
> >
> > Index: linux-pm/kernel/sched/idle.c
> > ===================================================================
> > --- linux-pm.orig/kernel/sched/idle.c
> > +++ linux-pm/kernel/sched/idle.c
> > @@ -96,6 +96,15 @@ void __cpuidle default_idle_call(void)
> > }
> > }
> >
> > +static int call_cpuidle_s2idle(struct cpuidle_driver *drv,
> > + struct cpuidle_device *dev)
> > +{
> > + if (current_clr_polling_and_test())
> > + return -EBUSY;
> > +
> > + return cpuidle_enter_s2idle(drv, dev);
> > +}
> > +
> > static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device
> > *dev,
> > int next_state)
> > {
> > @@ -171,11 +180,9 @@ static void cpuidle_idle_call(void)
> > if (idle_should_enter_s2idle()) {
> > rcu_idle_enter();
> >
> > - entered_state = cpuidle_enter_s2idle(drv, dev);
> > - if (entered_state > 0) {
> > - local_irq_enable();
> > + entered_state = call_cpuidle_s2idle(drv, dev);
> I guess this changes the context a little bit that(comparing to [1/2 patch],
> after this modification, when we found that TIF_NEED_RESCHED is set we can
> have
> a second chance in the following call_cpuidle to do a second s2idle try.
> However
> in [1/2 patch], it might exit the s2idle phase directly once when we see
> TIF_NEED_RESCHED is set(because entered_state is postive we treat it as a
> successful
> s2idle). In summary I think the change (patch [2/2]) is more robust.
Yeah, good point.
> Acked-by: Chen Yu <yu.c.c...@intel.com>
OK, thanks!
I'll queue up this one too along with the [1/2] for -rc4 then.
Thanks!
