From df8d9eeadd0f7a216f2476351d5aee43c6550bf0 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 29 Apr 2015 15:19:21 +0200 Subject: cpuidle: Run tick_broadcast_exit() with disabled interrupts Commit 335f49196fd6 (sched/idle: Use explicit broadcast oneshot control function) replaced clockevents_notify() invocations in cpuidle_idle_call() with direct calls to tick_broadcast_enter() and tick_broadcast_exit(), but it overlooked the fact that interrupts were already enabled before calling the latter which led to functional breakage on systems using idle states with the CPUIDLE_FLAG_TIMER_STOP flag set. Fix that by moving the invocations of tick_broadcast_enter() and tick_broadcast_exit() down into cpuidle_enter_state() where interrupts are still disabled when tick_broadcast_exit() is called. Also ensure that interrupts will be disabled before running tick_broadcast_exit() even if they have been enabled by the idle state's ->enter callback. Trigger a WARN_ON_ONCE() in that case, as we generally don't want that to happen for states with CPUIDLE_FLAG_TIMER_STOP set. Fixes: 335f49196fd6 (sched/idle: Use explicit broadcast oneshot control function) Reported-and-tested-by: Linus Walleij Acked-by: Peter Zijlstra (Intel) Acked-by: Daniel Lezcano Reported-and-tested-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki --- kernel/sched/idle.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index deef1caa94c6..fefcb1fa5160 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -81,7 +81,6 @@ static void cpuidle_idle_call(void) struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); int next_state, entered_state; - unsigned int broadcast; bool reflect; /* @@ -150,17 +149,6 @@ static void cpuidle_idle_call(void) goto exit_idle; } - broadcast = drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP; - - /* - * Tell the time framework to switch to a broadcast timer - * because our local timer will be shutdown. If a local timer - * is used from another cpu as a broadcast timer, this call may - * fail if it is not available - */ - if (broadcast && tick_broadcast_enter()) - goto use_default; - /* Take note of the planned idle state. */ idle_set_state(this_rq(), &drv->states[next_state]); @@ -174,8 +162,8 @@ static void cpuidle_idle_call(void) /* The cpu is no longer idle or about to enter idle. */ idle_set_state(this_rq(), NULL); - if (broadcast) - tick_broadcast_exit(); + if (entered_state == -EBUSY) + goto use_default; /* * Give the governor an opportunity to reflect on the outcome -- cgit v1.2.3