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authorFrederic Weisbecker <fweisbec@gmail.com>2012-08-22 17:27:34 +0200
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-09-23 07:44:46 -0700
commitb2fe1430d4115c74d007c825cb9dc3317f28bb16 (patch)
tree4f8eb3dbcb8f78e0aeb20757b22a31ca4761c2b9 /arch/h8300/kernel
parent41d8fe5bb3cf91ce2716ac8f43e4b40d802a99c8 (diff)
downloadop-kernel-dev-b2fe1430d4115c74d007c825cb9dc3317f28bb16.zip
op-kernel-dev-b2fe1430d4115c74d007c825cb9dc3317f28bb16.tar.gz
h8300: 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 h8300's idle loop. Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> 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/h8300/kernel')
-rw-r--r--arch/h8300/kernel/process.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
index 0e9c315..f153ed1 100644
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -36,6 +36,7 @@
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/slab.h>
+#include <linux/rcupdate.h>
#include <asm/uaccess.h>
#include <asm/traps.h>
@@ -78,8 +79,10 @@ void (*idle)(void) = default_idle;
void cpu_idle(void)
{
while (1) {
+ rcu_idle_enter();
while (!need_resched())
idle();
+ rcu_idle_exit();
schedule_preempt_disabled();
}
}
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