On Sat, Jan 9, 2016 at 9:48 AM, Tony Luck <tony.luck@xxxxxxxxx> wrote: > On Fri, Jan 8, 2016 at 5:49 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: >> On Jan 8, 2016 4:19 PM, "Tony Luck" <tony.luck@xxxxxxxxx> wrote: >>> >>> Make use of the EXTABLE_FAULT exception table entries. This routine >>> returns a structure to indicate the result of the copy: >> >> Perhaps this is silly, but could we make this feature depend on ERMS >> and thus make the code a lot simpler? > > ERMS? It's the fast string extension, aka Enhanced REP MOV STOS. On CPUs with that feature (and not disabled via MSR), plain ol' rep movs is the fastest way to copy bytes. I think this includes all Intel CPUs from SNB onwards. --Andy -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>