From 591c6d1710cd73824057d08eda302cf2a7cfd18a Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 8 Aug 2013 22:26:23 -0700 Subject: [PATCH] rcu: Flag lockless access to ->gp_flags with ACCESS_ONCE() This commit applies ACCESS_ONCE() to an outside-of-lock access to ->gp_flags. Although it is hard to imagine any sane compiler messing this particular case up, the documentation benefits are substantial. Plus the definition of "sane compiler" grows ever looser. Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 62b67b7..6d028fd 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1481,7 +1481,7 @@ static int __noreturn rcu_gp_kthread(void *arg) /* Handle grace-period start. */ for (;;) { wait_event_interruptible(rsp->gp_wq, - rsp->gp_flags & + ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_INIT); if (rcu_gp_init(rsp)) break; -- 2.7.4