Re: [rfc][patch 2/3] x86: fix IO write barriers

[Dave Jones <davej@redhat.com>]

On Thu, Oct 04, 2007 at 08:58:27PM +0200, Andi Kleen wrote:
 > On Thursday 04 October 2007 20:41:07 Dave Jones wrote:
 > > On Thu, Oct 04, 2007 at 08:21:59PM +0200, Andi Kleen wrote:
 > >  > On Thursday 04 October 2007 20:10:44 Dave Jones wrote:
 > >  > > On Thu, Oct 04, 2007 at 07:53:16PM +0200, Andi Kleen wrote:
 > >  > >  > 
 > >  > >  > > The only vendor that ever implemented OOSTOREs was Centaur, and they
 > >  > >  > > only did in the Winchip generation of the CPUs.  When they dropped it
 > >  > >  > > from the C3, I asked whether they intended to bring it back, and the
 > >  > >  > > answer was "extremely unlikely".
 > >  > >  > >
 > >  > >  > 
 > >  > >  > Do you know if it made a big performance difference?
 > >  > > 
 > >  > > On the winchip, it was a huge win. I can't remember exact numbers,
 > >  > > but pretty much every benchmark I threw at it at the time showed
 > >  > > significant improvement.
 > >  > 
 > >  > Significant as in >10%?
 > > 
 > > "Worth about 10-20% performance" according to the 2.4.18pre9-ac4
 > > release notes: http://www.linuxtoday.com/news_story.php3?ltsn=2002-02-14-015-20-NW-KN
 > 
 > Are there numbers for a newer kernel available too?

no idea, my winchips died about 5 years ago.

	Dave

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