rcu: Break more call_rcu() deadlock involving scheduler and perf

Commit 96d3fd0d31 (rcu: Break call_rcu() deadlock involving scheduler
and perf) covered the case where __call_rcu_nocb_enqueue() needs to wake
the rcuo kthread due to the queue being initially empty, but did not
do anything for the case where the queue was overflowing.  This commit
therefore also defers wakeup for the overflow case.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
2014-07-29 14:50:47 -07:00
parent 66d701ea7e
commit 9fdd3bc900
3 changed files with 28 additions and 10 deletions
+3
View File
@@ -180,9 +180,12 @@ TRACE_EVENT(rcu_grace_period_init,
* argument is a string as follows:
*
* "WakeEmpty": Wake rcuo kthread, first CB to empty list.
* "WakeEmptyIsDeferred": Wake rcuo kthread later, first CB to empty list.
* "WakeOvf": Wake rcuo kthread, CB list is huge.
* "WakeOvfIsDeferred": Wake rcuo kthread later, CB list is huge.
* "WakeNot": Don't wake rcuo kthread.
* "WakeNotPoll": Don't wake rcuo kthread because it is polling.
* "DeferredWake": Carried out the "IsDeferred" wakeup.
* "Poll": Start of new polling cycle for rcu_nocb_poll.
* "Sleep": Sleep waiting for CBs for !rcu_nocb_poll.
* "WokeEmpty": rcuo kthread woke to find empty list.