From: Paul Gortmaker <paul.gortma...@windriver.com>

The wait_event() at the head of the rcu_nocb_kthread() can result in
soft-lockup complaints if the CPU in question does not register RCU
callbacks for an extended period.  This commit therefore changes
the wait_event() to a wait_event_interruptible().

Reported-by: Frederic Weisbecker <fweis...@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortma...@windriver.com>
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
---
 kernel/rcutree_plugin.h |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index f6e5ec2..43dba2d 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -2366,10 +2366,11 @@ static int rcu_nocb_kthread(void *arg)
        for (;;) {
                /* If not polling, wait for next batch of callbacks. */
                if (!rcu_nocb_poll)
-                       wait_event(rdp->nocb_wq, rdp->nocb_head);
+                       wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
                list = ACCESS_ONCE(rdp->nocb_head);
                if (!list) {
                        schedule_timeout_interruptible(1);
+                       flush_signals(current);
                        continue;
                }
 
-- 
1.7.8

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

Reply via email to