[PATCH 11/16] rcu: Check for spurious wakeup using return value

[Pranith Kumar]

When the gp_kthread wakes up from the wait event, it returns 0 if the wake up is
due to the condition having been met. This commit checks this return value
for a spurious wake up before calling rcu_gp_init().

Signed-off-by: Pranith Kumar <bobby.prani@xxxxxxxxx>
---
 kernel/rcu/tree.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f8847d9..3b20ad2 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1790,11 +1790,11 @@ static int __noreturn rcu_gp_kthread(void *arg)
 					       ACCESS_ONCE(rsp->gpnum),
 					       TPS("reqwait"));
 			rsp->gp_state = RCU_GP_WAIT_GPS;
-			wait_event_interruptible(rsp->gp_wq,
+			ret = wait_event_interruptible(rsp->gp_wq,
 						 ACCESS_ONCE(rsp->gp_flags) &
 						 RCU_GP_FLAG_INIT);
 			/* Locking provides needed memory barrier. */
-			if (rcu_gp_init(rsp))
+			if (!ret && rcu_gp_init(rsp))
 				break;
 			cond_resched();
 			flush_signals(current);
-- 
2.0.0.rc2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/