[PATCH] workqueue: fix spurious CPU locality WARN fromprocess_one_work()
From: Tejun Heo
Date: Sun Jul 22 2012 - 12:44:19 EST
25511a4776 "workqueue: reimplement CPU online rebinding to handle idle
workers" added CPU locality sanity check in process_one_work(). It
triggers if a worker is executing on a different CPU without UNBOUND
or REBIND set.
This works for all normal workers but rescuers can trigger this
spuriously when they're serving the unbound or a disassociated
global_cwq - rescuers don't have either flag set and thus its
gcwq->cpu can be a different value including %WORK_CPU_UNBOUND.
Fix it by additionally testing %GCWQ_DISASSOCIATED.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Reported-by: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
This should fix it. Will queue it on wq/for-3.6.
kernel/workqueue.c | 6 ++++++
1 file changed, 6 insertions(+)
@@ -1949,7 +1949,13 @@ __acquires(&gcwq->lock)
+ * Ensure we're on the correct CPU. DISASSOCIATED test is
+ * necessary to avoid spurious warnings from rescuers servicing the
+ * unbound or a disassociated gcwq.
WARN_ON_ONCE(!(worker->flags & (WORKER_UNBOUND | WORKER_REBIND)) &&
+ !(gcwq->flags & GCWQ_DISASSOCIATED) &&
raw_smp_processor_id() != gcwq->cpu);
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/