Il 30/05/2013 14:34, Gleb Natapov ha scritto: >>> > > >>> > > Ah, we check kvm_apic_has_events() in runnable. Then yes, we will not >>> > > lose the event. >> > >> > Ok, then I'd prefer to have the cmpxchg directly in the if, as in >> > http://article.gmane.org/gmane.comp.emulators.kvm.devel/110505 >> > > I still do not. Both of them are tricky, mine does not coalesce events > needlessly. Agreed that both are tricky, but I don't think my patch is coalescing events. If you have INIT SIPI INIT SIPI ^ ^ INIT bit cleared here SIPI bit checked here my patch KVM sees apic_events = INIT | SIPI and deduces that the SIPI bit was set by the second SIPI, not by the first. In fact the first SIPI was cancelled by the second INIT, and thus should not be processed at all. Instead, with your patch KVM will service all four events; strictly speaking it is wrong to service the first SIPI, which is why I prefer having the cmpxchg in the beginning. Paolo -- 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
