From 0faba81b8678ef19ef509da34ec2a64ee27dfcba Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Aug 2012 17:27:34 +0200 Subject: mn10300: Add missing RCU idle APIs on idle loop commit 5b0753a90b7a98bc613c3767e9263a1a76d4f900 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 the mn10300's idle loop. Reported-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Cc: David Howells Cc: Koichi Yasutake Signed-off-by: Paul E. McKenney Acked-by: David Howells Reviewed-by: Josh Triplett Signed-off-by: Greg Kroah-Hartman --- arch/mn10300/kernel/process.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c index 7dab0cd3646..e9cceba193b 100644 --- a/arch/mn10300/kernel/process.c +++ b/arch/mn10300/kernel/process.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -107,6 +108,7 @@ void cpu_idle(void) { /* endless idle loop with no priority at all */ for (;;) { + rcu_idle_enter(); while (!need_resched()) { void (*idle)(void); @@ -121,6 +123,7 @@ void cpu_idle(void) } idle(); } + rcu_idle_exit(); schedule_preempt_disabled(); } -- cgit v1.2.3-18-g5258