Re: [PATCH] i386-pda UP optimization

[Andi Kleen]

On Wednesday 15 November 2006 12:27, Eric Dumazet wrote:
> Seeing %gs prefixes used now by i386 port, I recalled seeing strange oprofile 
> results on Opteron machines.
> 
> I really think %gs prefixes can be expensive in some (most ?) cases, even if 
> the Intel/AMD docs say they are free.

They aren't free, just very cheap.

> 
> With the attached patch, I got 12.212 s, and a kernel text size reduction of 
> 3400 bytes.

Are the benchmark numbers stable? i.e. if you repeat them multiple times
with reboots do you still get the same difference?

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/