From 6fec10a1a5866dda3cd6a825a521fc7c2f226ba5 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 22 Jul 2012 10:16:34 -0700 Subject: [PATCH] workqueue: fix spurious CPU locality WARN from process_one_work() 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 Reported-by: "Paul E. McKenney" LKML-Refence: <20120721213656.GA7783@linux.vnet.ibm.com> --- kernel/workqueue.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 471996a81633..692d97628a10 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1949,7 +1949,13 @@ __acquires(&gcwq->lock) lockdep_copy_map(&lockdep_map, &work->lockdep_map); #endif + /* + * 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); /*