lkml.org 
[lkml]   [2002]   [Dec]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Intel P6 vs P7 system call performance
Date
Followup to:  <20021209193649.GC10316@suse.de>
By author: Dave Jones <davej@codemonkey.org.uk>
In newsgroup: linux.dev.kernel
>
> On Mon, Dec 09, 2002 at 05:48:45PM +0000, Linus Torvalds wrote:
>
> > P4's really suck at system calls. A 2.8GHz P4 does a simple system call
> > a lot _slower_ than a 500MHz PIII.
> >
> > The P4 has problems with some other things too, but the "int + iret"
> > instruction combination is absolutely the worst I've seen. A 1.2GHz
> > Athlon will be 5-10 times faster than the fastest P4 on system call
> > overhead.
>
> Time to look into an alternative like SYSCALL perhaps ?
>

SYSCALL is AMD. SYSENTER is Intel, and is likely to be significantly
faster. Unfortunately SYSENTER is also extremely braindamaged, in
that it destroys *both* the EIP and the ESP beyond recovery, and
because it's allowed in V86 and 16-bit modes (where it will cause
permanent data loss) which means that it needs to be able to be turned
off for things like DOSEMU and WINE to work correctly.

-hpa

--
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt <amsp@zytor.com>
-
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 13:31    [from the cache]
©2003-2011 Jasper Spaans