Commit-ID: 0ee23fda59740767324b4340247ca41a2f498ca6 Gitweb: http://git.kernel.org/tip/0ee23fda59740767324b4340247ca41a2f498ca6 Author: Frederic Weisbecker <fweisbec@xxxxxxxxx> AuthorDate: Wed, 22 Aug 2012 17:27:34 +0200 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Sun, 23 Sep 2012 07:44:50 -0700 score: Add missing RCU idle APIs on idle loop 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 <paulmck@xxxxxxxxxxxxxxxxxx> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Chen Liqin <liqin.chen@xxxxxxxxxxxxx> Cc: Lennox Wu <lennox.wu@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 3.3+ Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> --- arch/score/kernel/process.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c index 2707023..637970c 100644 --- a/arch/score/kernel/process.c +++ b/arch/score/kernel/process.c @@ -27,6 +27,7 @@ #include <linux/reboot.h> #include <linux/elfcore.h> #include <linux/pm.h> +#include <linux/rcupdate.h> 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(); } } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html