Messages in this thread | | | Subject | Re: Slowdown with randomize_va_space in 2.6.12.2 | From | Arjan van de Ven <> | Date | Thu, 07 Jul 2005 08:37:08 +0200 |
| |
On Wed, 2005-07-06 at 18:12 -0700, Andrew Morton wrote: > Dave Jones <davej@redhat.com> wrote: > > > > On Wed, Jul 06, 2005 at 12:57:19PM -0700, David S. Miller wrote: > > > From: Paulo Marques <pmarques@grupopie.com> > > > Date: Wed, 06 Jul 2005 15:23:56 +0100 > > > > > > > What is weird is that most of the extra time is being accounted as > > > > user-space time, but the user-space application is exactly the same in > > > > both runs, only the "randomize_va_space" parameter changed. > > > > > > It might be attributable to more cpu cache misses in userspace since > > > the virtual addresses of everything are changing each and every > > > invocation. > > > > On Transmeta CPUs that probably triggers a retranslation of > > x86->native bytecode, if it thinks it hasn't seen code at that > > address before. > > > > ouch. What do we do? Default to off? Default to off on xmeta?
off-on-xmeta would be my preference; I'll cook up a patch for that.
- 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/
| |