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| author | Peter Zijlstra <peterz@infradead.org> | 2020-08-07 20:50:19 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-08-26 12:41:53 +0200 |
| commit | 1098582a0f6c4e8fd28da0a6305f9233d02c9c1d (patch) | |
| tree | bda70ef4f575f5c5e3d8e957cd5d88125dbddf9e /drivers/cpuidle | |
| parent | cpuidle: Fixup IRQ state (diff) | |
| download | linux-1098582a0f6c4e8fd28da0a6305f9233d02c9c1d.tar.xz linux-1098582a0f6c4e8fd28da0a6305f9233d02c9c1d.zip | |
sched,idle,rcu: Push rcu_idle deeper into the idle path
Lots of things take locks, due to a wee bug, rcu_lockdep didn't notice
that the locking tracepoints were using RCU.
Push rcu_idle_{enter,exit}() as deep as possible into the idle paths,
this also resolves a lot of _rcuidle()/RCU_NONIDLE() usage.
Specifically, sched_clock_idle_wakeup_event() will use ktime which
will use seqlocks which will tickle lockdep, and
stop_critical_timings() uses lock.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.310943801@infradead.org
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 2fe4f3cdf54d..9bcda4153d3b 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -145,13 +145,14 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, * executing it contains RCU usage regarded as invalid in the idle * context, so tell RCU about that. */ - RCU_NONIDLE(tick_freeze()); + tick_freeze(); /* * The state used here cannot be a "coupled" one, because the "coupled" * cpuidle mechanism enables interrupts and doing that with timekeeping * suspended is generally unsafe. */ stop_critical_timings(); + rcu_idle_enter(); drv->states[index].enter_s2idle(dev, drv, index); if (WARN_ON_ONCE(!irqs_disabled())) local_irq_disable(); @@ -160,7 +161,8 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, * first CPU executing it calls functions containing RCU read-side * critical sections, so tell RCU about that. */ - RCU_NONIDLE(tick_unfreeze()); + rcu_idle_exit(); + tick_unfreeze(); start_critical_timings(); time_end = ns_to_ktime(local_clock()); @@ -229,16 +231,18 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, /* Take note of the planned idle state. */ sched_idle_set_state(target_state); - trace_cpu_idle_rcuidle(index, dev->cpu); + trace_cpu_idle(index, dev->cpu); time_start = ns_to_ktime(local_clock()); stop_critical_timings(); + rcu_idle_enter(); entered_state = target_state->enter(dev, drv, index); + rcu_idle_exit(); start_critical_timings(); sched_clock_idle_wakeup_event(); time_end = ns_to_ktime(local_clock()); - trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); + trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu); /* The cpu is no longer idle or about to enter idle. */ sched_idle_set_state(NULL); |