On 11/29, H. Peter Anvin wrote: > > On 11/29/2013 12:35 PM, Oleg Nesterov wrote: > > On 11/29, H. Peter Anvin wrote: > >> > >> On 11/29/2013 12:05 PM, Oleg Nesterov wrote: > >>> > >>> Can't we invalidate pte (so that any user will stuck in page fault), > >>> update the page(s), restore the pte and drop the locks? > >> > >> That would require a global TLB shootdown > > > > Well, it is not really global, it is for mm_cpumask() and for good > > reason? > > > > And is it really worse than on_each_cpu(do_sync_core) and the usage > > of text_mutex? > > > > Probably not, but one would have to consider the total amount of > synchronization needed.
Yes, agreed, this should be justified. > >> (and wouldn't help > >> shared-memory code segments, if we care about that at all.) > > > > Well, I think this should only support the private mappings. > > > > Well, what do you do if someone tries this on a MAP_SHARED mapping? > Error out? Imho yes. But this needs more discussion, and afaics this is a bit offtopic. Please note that this patch relies on bp_target_mm, this can't help in VM_SHARED case too. Oleg. -- 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/
