[lkml]   [2012]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v4 0/8] Avoid cache trashing on clearing huge/gigantic page
On Mon, 20 Aug 2012 16:52:29 +0300
"Kirill A. Shutemov" <> 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!

 \ /
  Last update: 2012-09-14 01:41    [W:0.075 / U:12.564 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site