RE: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata

[richard . brunner]

Jun,

I have to agree with what Andi says. It is in a slow path,
and we want to guard against user programs that could hit it.
Making it conditional doesn't buy a lot and would cause lots of
re-validation of the patch that we would like
to avoid so we can get this in to the 2.6 kernel ASAP. 
Don't worry! I am pretty certain the patch won't impact the 
performance of the 2.6 kernel on processors from other vendors ;-)

                       Thanks!
                                          ]-Rich ...
                                          ]AMD Fellow
> From: Nakajima, Jun [mailto:jun.nakajima@xxxxxxxxx] 
>
> > I would hate to break this again just to save a few hundred bytes in 
> > this function. Also the overhead is very low so it is also not 
> > interesting to make it conditional for speed reasons.
> 
> For maintenance and testing purposes, I think it's still 
> better to make it conditional. If the errata are fixed, you 
> might want to kill the condition depending on the stepping, 
> for example. During the transition time, you need to support 
> both the steppings until old ones go away (then remove the 
> workaround).
> 
> Thanks,
> Jun

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