| Message ID | 20200922091550.90191-1-ulf.hansson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | cpuidle: Drop misleading comments about RCU usage | expand |
On Tue, Sep 22, 2020 at 11:16 AM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > The commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the > idle path"), moved the calls rcu_idle_enter|exit() into the cpuidle core. > > However, it forgot to remove a couple of comments in enter_s2idle_proper() > about why RCU_NONIDLE earlier was needed. So, let's drop them as they have > become a bit misleading. > > Cc: Peter Zijlstra (Intel) <peterz@infradead.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Applied as 5.9-rc7 material, thanks! > --- > drivers/cpuidle/cpuidle.c | 10 ---------- > 1 file changed, 10 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 6c7e5621cf9a..29e84687f3c3 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -142,11 +142,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, > > time_start = ns_to_ktime(local_clock()); > > - /* > - * trace_suspend_resume() called by tick_freeze() for the last CPU > - * executing it contains RCU usage regarded as invalid in the idle > - * context, so tell RCU about that. > - */ > tick_freeze(); > /* > * The state used here cannot be a "coupled" one, because the "coupled" > @@ -159,11 +154,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, > target_state->enter_s2idle(dev, drv, index); > if (WARN_ON_ONCE(!irqs_disabled())) > local_irq_disable(); > - /* > - * timekeeping_resume() that will be called by tick_unfreeze() for the > - * first CPU executing it calls functions containing RCU read-side > - * critical sections, so tell RCU about that. > - */ > if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) > rcu_idle_exit(); > tick_unfreeze(); > -- > 2.25.1 >
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 6c7e5621cf9a..29e84687f3c3 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -142,11 +142,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, time_start = ns_to_ktime(local_clock()); - /* - * trace_suspend_resume() called by tick_freeze() for the last CPU - * executing it contains RCU usage regarded as invalid in the idle - * context, so tell RCU about that. - */ tick_freeze(); /* * The state used here cannot be a "coupled" one, because the "coupled" @@ -159,11 +154,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, target_state->enter_s2idle(dev, drv, index); if (WARN_ON_ONCE(!irqs_disabled())) local_irq_disable(); - /* - * timekeeping_resume() that will be called by tick_unfreeze() for the - * first CPU executing it calls functions containing RCU read-side - * critical sections, so tell RCU about that. - */ if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) rcu_idle_exit(); tick_unfreeze();
The commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the idle path"), moved the calls rcu_idle_enter|exit() into the cpuidle core. However, it forgot to remove a couple of comments in enter_s2idle_proper() about why RCU_NONIDLE earlier was needed. So, let's drop them as they have become a bit misleading. Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/cpuidle/cpuidle.c | 10 ---------- 1 file changed, 10 deletions(-)