Hi Oren, On Thu, May 15, 2014 at 10:05:05AM +0300, Oren Twaig wrote: > > On 05/15/2014 08:00 PM, Anthony Iliopoulos wrote: > > I have dismissed this case, since I assume that there are many more > > cycles spent in servicing the TLB invalidation IPI, walking the pgtable > > plus other related overhead (e.g. sched) than in updating the pte/pmd > > so I am not sure how possible it would be to hit this condition. > > Hi Anthony, > > I have a question about the above statement. What will happen with multi > cpu VMs ? won't the race described above can happen ? I.e one virtual CPU > can will visit the host and the other will continue to encounter your race ? I don't think there will be any race for the vcpu cases, since the sptes will be cleared via the mmu_notifier, so this should take care of it in the same manner as ptep_get_and_clear() does, as described by Dave earlier in this thread. Regards, Anthony -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
