| Message ID | 20120722164327.GA5144@dhcp-172-17-108-109.mtv.corp.google.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Sun, Jul 22, 2012 at 09:43:27AM -0700, Tejun Heo wrote: > 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@kernel.org> > Reported-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > LKML-Refence: <20120721213656.GA7783@linux.vnet.ibm.com> > --- > This should fix it. Will queue it on wq/for-3.6. I am running my tests on it, will let you know how it goes. Thanx, Paul > Thanks! > > kernel/workqueue.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > --- 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); > > /* > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- 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); /*
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@kernel.org> Reported-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Refence: <20120721213656.GA7783@linux.vnet.ibm.com> --- This should fix it. Will queue it on wq/for-3.6. Thanks! kernel/workqueue.c | 6 ++++++ 1 file changed, 6 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html