lkml.org 
[lkml]   [2007]   [Jun]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: why does the macro "ZERO_PAGE" take an argument?
H. Peter Anvin wrote:
> William Lee Irwin III wrote:
>
>>Robert P. J. Day wrote:
>>
>>>>although it's not clear where in the source tree are the invocations
>>>>that would actually make a difference to a MIPS system, which is why
>>>>i've CC'ed ralf on this. i'm sure he can clear this up. :-)
>>
>>On Thu, Jun 07, 2007 at 10:32:29AM -0700, H. Peter Anvin wrote:
>>
>>>x86 could also benefit from coloured zeropages. In fact, I thought it
>>>already had them (K8 wants as many as 8.)
>>
>>How would one demonstrate the beneficial effect of such?
>
>
> Dean Gaudet at Transmeta did some benchmarking using SPEC. If I recall
> his numbers correctly (this is from memory, mind you) on Transmeta
> Efficeon, which has 2-way virtual cache tagging with hardware recovery,
> zeropage coloring was a 1.5% performance improvement.

I'm surprised that the benchmark made such use of zero pages so as to
be worthwhile. I'm sitting on a patch which removes the zero page from
the page fault fastpath completely which I'd like to try out in -mm...

--
SUSE Labs, Novell Inc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-06-12 04:21    [W:0.350 / U:0.272 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site