On Mon, Jul 13, 2009 at 11:03:56AM -0400, Gregory Haskins wrote: > Gleb Natapov wrote: > > On Mon, Jul 13, 2009 at 10:29:02AM -0400, Gregory Haskins wrote: > > > >> Gleb Natapov wrote: > >> > >>> diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c > >>> index 6c57e46..ce8fcd3 100644 > >>> --- a/virt/kvm/irq_comm.c > >>> +++ b/virt/kvm/irq_comm.c > >>> @@ -210,7 +210,8 @@ int kvm_request_irq_source_id(struct kvm *kvm) > >>> unsigned long *bitmap = &kvm->arch.irq_sources_bitmap; > >>> int irq_source_id; > >>> > >>> - mutex_lock(&kvm->irq_lock); > >>> + WARN_ON(!mutex_is_locked(&kvm->lock)); > >>> > >>> > >> Shouldn't this be fatal? (e.g. BUG_ON). I know the usage between > >> BUG/WARN is controversial, but it seems to me that something is > >> completely broken if you expect it to be locked and its not. Might as > >> well fail the system, IMO. > >> > >> > > Well I don't really care but we have WARN_ON() in the code currently. > > > > Well, that is perhaps unfortunate, but not relevant. I am not reviewing > those patches ;) > > > Besides the chances are good that even without locking around this > > function nothing will break, so why kill host kernel? > > > > The question to ask is: Is it legal to continue to run if the mutex is > found unlocked? If not, the offending caller should be found/fixed as > early as possible IMO, and an oops should be sufficient to do so. I > think WARN_ON tends to gets overused/abused, so lets not perpetuate it > simply because of precedence. > I will have to end this particular thread about WARN_ON by stating that Avi told me to put it there. I'll let him decide. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
