Re: Slowdown with randomize_va_space in 2.6.12.2

[Andrew Morton]

Dave Jones <davej@xxxxxxxxxx> wrote:
>
> On Wed, Jul 06, 2005 at 12:57:19PM -0700, David S. Miller wrote:
>  > From: Paulo Marques <pmarques@xxxxxxxxxxxx>
>  > 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?
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