lkml.org 
[lkml]   [2002]   [Sep]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Performance issue in 2.5.32+
On Sun, 8 Sep 2002, Linus Torvalds wrote:

> I don't really see anythign very suspicious in the 31->32 changelogs.
> Somebody else already mentioned TLS etc, but that shouldn't really be
> noticeable...

I've now tracked the problem to the introduction of the new mtrr code, and
backing it out for 2.5.32 restores original performance. From what I can
tell, the new code is not handling a bios/hardware bug that the old code
was.

The old mtrr code says this during bootup:
mtrr: your CPUs had inconsistent fixed MTRR settings
mtrr: your CPUs had inconsistent variable MTRR settings
mtrr: probably your BIOS does not setup all CPUs

While the new code just says:
mtrr: SMP support incomplete for this vendor

The peformance hit is basically the same as when the old mtrr code is
disabled. I'll have a poke around and see if I can find out why the new
mtrr code isn't handling the problem.


- James
--
James Morris
<jmorris@intercode.com.au>


-
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: 2005-03-22 13:28    [W:0.074 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site