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authorFrederic Weisbecker <fweisbec@gmail.com>2012-08-22 17:27:34 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-13 05:38:55 +0900
commit1b5124a305593deffd6186540546b8bfba429570 (patch)
treed3732cfdf2706d34f64353751079c30e01a49809 /arch
parenta3e9082a19d723e7be0bc51d851b5689eee67c9c (diff)
m32r: Add missing RCU idle APIs on idle loop
commit 48ae077cfce72591b8fc80e1dcc87806f86fed7f 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 m32r's idle loop. Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/m32r/kernel/process.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index 3a4a32b27208..384e63f3a4c4 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -26,6 +26,7 @@
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/hardirq.h>
+#include <linux/rcupdate.h>
#include <asm/io.h>
#include <asm/uaccess.h>
@@ -82,6 +83,7 @@ void cpu_idle (void)
{
/* endless idle loop with no priority at all */
while (1) {
+ rcu_idle_enter();
while (!need_resched()) {
void (*idle)(void) = pm_idle;
@@ -90,6 +92,7 @@ void cpu_idle (void)
idle();
}
+ rcu_idle_exit();
schedule_preempt_disabled();
}
}