On Mon, 20 Aug 2012 16:52:29 +0300 "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > Clearing a 2MB huge page will typically blow away several levels of CPU > caches. To avoid this only cache clear the 4K area around the fault > address and use a cache avoiding clears for the rest of the 2MB area. > > This patchset implements cache avoiding version of clear_page only for > x86. If an architecture wants to provide cache avoiding version of > clear_page it should to define ARCH_HAS_USER_NOCACHE to 1 and implement > clear_page_nocache() and clear_user_highpage_nocache(). Patchset looks nice to me, but the changelogs are terribly short of performance measurements. For this sort of change I do think it is important that pretty exhaustive testing be performed, and that the results (or a readable summary of them) be shown. And that testing should be designed to probe for slowdowns, not just the speedups!
