From: Peter Zijlstra <peterz@infradead.org>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
stable@vger.kernel.org, Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH 2/5] rcu/nocb: Perform deferred wake up before last idle's need_resched() check
Date: Mon, 8 Feb 2021 15:45:50 +0100 [thread overview]
Message-ID: <YCFOnhwQAjMMkwGN@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210131230548.32970-3-frederic@kernel.org>
On Mon, Feb 01, 2021 at 12:05:45AM +0100, Frederic Weisbecker wrote:
> diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
> index 305727ea0677..b601a3aa2152 100644
> --- a/kernel/sched/idle.c
> +++ b/kernel/sched/idle.c
> @@ -55,6 +55,7 @@ __setup("hlt", cpu_idle_nopoll_setup);
> static noinline int __cpuidle cpu_idle_poll(void)
> {
> trace_cpu_idle(0, smp_processor_id());
> + rcu_nocb_flush_deferred_wakeup();
> stop_critical_timings();
> rcu_idle_enter();
> local_irq_enable();
> @@ -173,6 +174,8 @@ static void cpuidle_idle_call(void)
> struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
> int next_state, entered_state;
>
> + rcu_nocb_flush_deferred_wakeup();
> +
> /*
> * Check if the idle task must be rescheduled. If it is the
> * case, exit the function after re-enabling the local irq.
Ok if I do this instead?
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -55,7 +55,6 @@ __setup("hlt", cpu_idle_nopoll_setup);
static noinline int __cpuidle cpu_idle_poll(void)
{
trace_cpu_idle(0, smp_processor_id());
- rcu_nocb_flush_deferred_wakeup();
stop_critical_timings();
rcu_idle_enter();
local_irq_enable();
@@ -174,8 +173,6 @@ static void cpuidle_idle_call(void)
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
int next_state, entered_state;
- rcu_nocb_flush_deferred_wakeup();
-
/*
* Check if the idle task must be rescheduled. If it is the
* case, exit the function after re-enabling the local irq.
@@ -288,6 +285,7 @@ static void do_idle(void)
}
arch_cpu_idle_enter();
+ rcu_nocb_flush_deferred_wakeup();
/*
* In poll mode we reenable interrupts and spin. Also if we
next prev parent reply other threads:[~2021-02-08 14:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-31 23:05 [PATCH 0/5] rcu/sched: Fix ignored rescheduling after rcu_eqs_enter() v4 Frederic Weisbecker
2021-01-31 23:05 ` [PATCH 1/5] rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers Frederic Weisbecker
2021-02-10 13:53 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2021-02-17 13:17 ` tip-bot2 for Frederic Weisbecker
2021-01-31 23:05 ` [PATCH 2/5] rcu/nocb: Perform deferred wake up before last idle's need_resched() check Frederic Weisbecker
2021-02-08 14:45 ` Peter Zijlstra [this message]
2021-02-08 14:53 ` Frederic Weisbecker
2021-02-10 13:53 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2021-02-17 13:17 ` tip-bot2 for Frederic Weisbecker
2021-01-31 23:05 ` [PATCH 3/5] rcu/nocb: Trigger self-IPI on late deferred wake up before user resume Frederic Weisbecker
2021-02-10 13:53 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2021-02-17 13:17 ` tip-bot2 for Frederic Weisbecker
2021-01-31 23:05 ` [PATCH 4/5] entry: Explicitly flush pending rcuog wakeup before last rescheduling point Frederic Weisbecker
2021-02-10 13:53 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2021-02-17 13:17 ` tip-bot2 for Frederic Weisbecker
2021-01-31 23:05 ` [PATCH 5/5] entry/kvm: " Frederic Weisbecker
2021-02-10 13:53 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2021-02-17 13:17 ` tip-bot2 for Frederic Weisbecker
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