[PATCH tip/core/rcu 3/8] waketorture: Don't kick unless grace period or request

From	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	[PATCH tip/core/rcu 3/8] waketorture: Don't kick unless grace period or request
Date	2016-06-16 00:30 +0200
Message-ID	<rKrtU-8sD-11@gated-at.bofh.it> (permalink)
References	<rKrtU-8sD-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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The current code can result in spurious kicks when there are no grace
periods in progress and no grace-period-related requests.  This is
sort of OK for a diagnostic aid, but the resulting ftrace-dump messages
in dmesg are annoying.  This commit therefore avoids spurious kicks
in the common case.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcu/tree.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f433959e9322..88d3f9590322 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1306,7 +1306,8 @@ static void rcu_stall_kick_kthreads(struct rcu_state *rsp)
 	if (!rcu_kick_kthreads)
 		return;
 	j = READ_ONCE(rsp->jiffies_kick_kthreads);
-	if (time_after(jiffies, j) && rsp->gp_kthread) {
+	if (time_after(jiffies, j) && rsp->gp_kthread &&
+	    (rcu_gp_in_progress(rsp) || READ_ONCE(rsp->gp_flags))) {
 		WARN_ONCE(1, "Kicking %s grace-period kthread\n", rsp->name);
 		rcu_ftrace_dump(DUMP_ALL);
 		wake_up_process(rsp->gp_kthread);
-- 
2.5.2

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[PATCH tip/core/rcu 3/8] waketorture: Don't kick unless grace period or request "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-06-16 00:30 +0200

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