On Thu, Jul 11, 2024 at 01:33:23AM +0300, Kirill A. Shutemov wrote: > On Wed, Jul 10, 2024 at 07:18:36PM +0200, Borislav Petkov wrote: > > On Wed, Jul 10, 2024 at 07:06:39PM +0300, Alexander Shishkin wrote: > > > static void text_poke_memcpy(void *dst, const void *src, size_t len) > > > { > > > - memcpy(dst, src, len); > > > + stac(); > > > + __inline_memcpy(dst, src, len); > > > + clac(); > > > > I think you need LASS-specific stac()/clac() or an alternative_2 or so. You > > can't cause that perf penalty on !LASS machines. > > Hm. Do we have text_poke() in hot path? > > Even if we do, I doubt flipping AC flag would make any performance > difference in context of all locking and TLB flushing we do in this > codepath. The one where performance might matter is text_poke_early(), the full fat one is comically slow as you point out.