lkml.org 
[lkml]   [2002]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Intel P6 vs P7 system call performance
Hi!

> >>don't many of the multi-CPU problems with tsc go away because you've got a
> >>per-cpu physical page for the vsyscall?
> >>
> >>i.e. per-cpu tsc epoch and scaling can be set on that page.
> >
> > Problem is that cpu's can randomly drift +/- 100 clocks or so... Not
> > nice at all.
> >
>
> ­­?100 clocks is what... ?50 ns these days? You can't get that kind of
> accuracy for anything outside the CPU core anyway...

50ns is bad enough when it makes your time go backwards.

Pavel
--
Casualities in World Trade Center: ~3k dead inside the building,
cryptography in U.S.A. and free speech in Czech Republic.
-
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    [W:0.076 / U:2.520 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site