On Fri, Feb 20, 2015 at 11:41 AM, Ingo Molnar <mi...@kernel.org> wrote: > > I'm not so sure about that aspect: I think disabling IRQs > might be necessary with some APICs (if lower levels don't > disable IRQs), to make sure the 'local APIC busy' bit isn't > set:
Right. But afaik not for the x2apic case, which this is. The x2apic doesn't even have a busy bit, and sending the ipi is a single write, I agree that when doing other apic implementations, we may need to guarantee atomicity for things like "wait for apic idle, then send the ipi". Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/