On Tue, Aug 1, 2017 at 7:15 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > On Tue, Aug 01, 2017 at 03:58:49PM +0200, Peter Zijlstra wrote: >> On Tue, Aug 01, 2017 at 06:43:14AM -0700, Andy Lutomirski wrote: >> > Anyway, can you document whatever property you require with a comment >> > in switch_mm() or wherever you're finding that property so that future >> > arch changes don't break it? >> >> We need _a_ smp_mb after rq->curr store. x86 has plenty. > > That is, we need it when we change to a different !0 mm. And we have the > mm_cpumask() atomics at the very least, even if loading a new CR3 would > not be serializing. I'm 99.5% sure that loading a new CR3 is always serializing even if it doesn't flush the TLB. -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
