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authorFrederic Weisbecker <fweisbec@gmail.com>2012-08-22 19:27:34 +0400
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-09-23 18:44:44 +0400
commitc633f9e788928e91ad11f44df29b47bbbe9550b0 (patch)
tree8f2326575c38a07620db45570d146b3232e81b48 /arch/cris
parent4c94cada48f7c660eca582be6032427a5e367117 (diff)
downloadlinux-c633f9e788928e91ad11f44df29b47bbbe9550b0.tar.xz
cris: 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 the Cris's idle loop. Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Cris <linux-cris-kernel@axis.com> Cc: <stable@vger.kernel.org> # 3.3+ Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'arch/cris')
-rw-r--r--arch/cris/kernel/process.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/cris/kernel/process.c b/arch/cris/kernel/process.c
index 66fd01728790..7f65be6f7f17 100644
--- a/arch/cris/kernel/process.c
+++ b/arch/cris/kernel/process.c
@@ -25,6 +25,7 @@
#include <linux/elfcore.h>
#include <linux/mqueue.h>
#include <linux/reboot.h>
+#include <linux/rcupdate.h>
//#define DEBUG
@@ -74,6 +75,7 @@ void cpu_idle (void)
{
/* endless idle loop with no priority at all */
while (1) {
+ rcu_idle_enter();
while (!need_resched()) {
void (*idle)(void);
/*
@@ -86,6 +88,7 @@ void cpu_idle (void)
idle = default_idle;
idle();
}
+ rcu_idle_exit();
schedule_preempt_disabled();
}
}