From: Paul E. McKenney Date: Mon, 13 Aug 2012 18:17:06 +0000 (-0700) Subject: rcu: Avoid spurious RCU CPU stall warnings X-Git-Tag: v3.7-rc1~37^2~2^2~2^3~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c96ea7cfdd88d0a67c970502bc5313fede34b86b;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git rcu: Avoid spurious RCU CPU stall warnings If a given CPU avoids the idle loop but also avoids starting a new RCU grace period for a full minute, RCU can issue spurious RCU CPU stall warnings. This commit fixes this issue by adding a check for ongoing grace period to avoid these spurious stall warnings. Reported-by: Becky Bruce Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 2cf8eb3..98f2752 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -819,7 +819,8 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) j = ACCESS_ONCE(jiffies); js = ACCESS_ONCE(rsp->jiffies_stall); rnp = rdp->mynode; - if ((ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && ULONG_CMP_GE(j, js)) { + if (rcu_gp_in_progress(rsp) && + (ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && ULONG_CMP_GE(j, js)) { /* We haven't checked in, so go dump stack. */ print_cpu_stall(rsp);