Messages in this thread | | | Date | Mon, 10 Mar 2008 11:12:45 -0700 | From | Suresh Siddha <> | Subject | Re: [PATCH] keep rd->online and cpu_online_map in sync |
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On Mon, Mar 10, 2008 at 09:39:34AM -0400, Gregory Haskins wrote: > keep rd->online and cpu_online_map in sync > > It is possible to allow the root-domain cache of online cpus to > become out of sync with the global cpu_online_map. This is because we > currently trigger removal of cpus too early in the notifier chain. > Other DOWN_PREPARE handlers may in fact run and reconfigure the > root-domain topology, thereby stomping on our own offline handling. > > The end result is that rd->online may become out of sync with > cpu_online_map, which results in potential task misrouting. > > So change the offline handling to be more tightly coupled with the > global offline process by triggering on CPU_DYING intead of > CPU_DOWN_PREPARE. > > Signed-off-by: Gregory Haskins <ghaskins@novell.com> > --- > > kernel/sched.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kernel/sched.c b/kernel/sched.c > index 52b9867..a616fa1 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -5881,7 +5881,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) > spin_unlock_irq(&rq->lock); > break; > > - case CPU_DOWN_PREPARE: > + case CPU_DYING:
Don't we need to take care of CPU_DYING_FROZEN aswell?
> /* Update our root-domain */ > rq = cpu_rq(cpu); > spin_lock_irqsave(&rq->lock, flags); >
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