From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Chen Yu <yu.c.chen@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Len Brown <len.brown@intel.com>,
Linux PM <linux-pm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Len Brown <lenb@kernel.org>
Subject: Re: [PATCH 2/2][v3] PM / s2idle: Code cleanup to make s2idle consistent with normal idle path
Date: Thu, 25 Jun 2020 12:49:02 +0200 [thread overview]
Message-ID: <CAJZ5v0jD__jK_tkNHk_ZqKEfdGiDa_afL5f65k3=z-8ZSq_UFQ@mail.gmail.com> (raw)
In-Reply-To: <20200625051534.GA22907@chenyu-office.sh.intel.com>
On Thu, Jun 25, 2020 at 7:14 AM Chen Yu <yu.c.chen@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.wysocki@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.wysocki@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.chen@intel.com>
OK, thanks!
I'll queue up this one too along with the [1/2] for -rc4 then.
Thanks!
prev parent reply other threads:[~2020-06-25 10:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 6:31 [PATCH 0/2][v3] Fix IPI missing issue when woken from suspend to idle Chen Yu
2020-06-23 6:31 ` [PATCH 1/2][v3] PM / s2idle: Clear _TIF_POLLING_NRFLAG before " Chen Yu
2020-06-23 15:13 ` Rafael J. Wysocki
2020-06-23 6:31 ` [PATCH 2/2][v3] PM / s2idle: Code cleanup to make s2idle consistent with normal idle path Chen Yu
2020-06-23 17:57 ` Rafael J. Wysocki
2020-06-25 5:15 ` Chen Yu
2020-06-25 10:49 ` Rafael J. Wysocki [this message]
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