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| author | Peter Zijlstra <peterz@infradead.org> | 2020-09-15 12:32:00 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-09-16 19:36:26 +0200 |
| commit | 8747f2022fe8d8029193707ee86ff5c792cbef9b (patch) | |
| tree | fdb28a11eb16c420a68394a907eb7c5f9e5c10d4 | |
| parent | ACPI: processor: Use CPUIDLE_FLAG_TLB_FLUSHED (diff) | |
| download | linux-8747f2022fe8d8029193707ee86ff5c792cbef9b.tar.xz linux-8747f2022fe8d8029193707ee86ff5c792cbef9b.zip | |
cpuidle: Allow cpuidle drivers to take over RCU-idle
Some drivers have to do significant work, some of which relies on RCU
still being active. Instead of using RCU_NONIDLE in the drivers and
flipping RCU back on, allow drivers to take over RCU-idle duty.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 15 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 1 |
2 files changed, 11 insertions, 5 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 04becd70cc41..6c7e5621cf9a 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -138,6 +138,7 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, struct cpuidle_device *dev, int index) { ktime_t time_start, time_end; + struct cpuidle_state *target_state = &drv->states[index]; time_start = ns_to_ktime(local_clock()); @@ -153,8 +154,9 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, * suspended is generally unsafe. */ stop_critical_timings(); - rcu_idle_enter(); - drv->states[index].enter_s2idle(dev, drv, index); + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + rcu_idle_enter(); + target_state->enter_s2idle(dev, drv, index); if (WARN_ON_ONCE(!irqs_disabled())) local_irq_disable(); /* @@ -162,7 +164,8 @@ 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_idle_exit(); + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + rcu_idle_exit(); tick_unfreeze(); start_critical_timings(); @@ -239,9 +242,11 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, time_start = ns_to_ktime(local_clock()); stop_critical_timings(); - rcu_idle_enter(); + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + rcu_idle_enter(); entered_state = target_state->enter(dev, drv, index); - rcu_idle_exit(); + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + rcu_idle_exit(); start_critical_timings(); sched_clock_idle_wakeup_event(); diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 75895e6363b8..6175c77bf25e 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -82,6 +82,7 @@ struct cpuidle_state { #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */ #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ #define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */ +#define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */ struct cpuidle_device_kobj; struct cpuidle_state_kobj; |