From 4a94001bd83f18ff3f3b998899d250d96f60a503 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Aug 2012 17:27:34 +0200 Subject: score: Add missing RCU idle APIs on idle loop commit 0ee23fda59740767324b4340247ca41a2f498ca6 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in scores's idle loop. Reported-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Cc: Chen Liqin Cc: Lennox Wu Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett Signed-off-by: Greg Kroah-Hartman --- arch/score/kernel/process.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/score') diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c index 2707023c7563..637970cfd3f4 100644 --- a/arch/score/kernel/process.c +++ b/arch/score/kernel/process.c @@ -27,6 +27,7 @@ #include #include #include +#include void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); @@ -50,9 +51,10 @@ void __noreturn cpu_idle(void) { /* endless idle loop with no priority at all */ while (1) { + rcu_idle_enter(); while (!need_resched()) barrier(); - + rcu_idle_exit(); schedule_preempt_disabled(); } } -- cgit v1.2.3