Re: [patch 2.6.13-rc3a] i386: inline restore_fpu

[Adrian Bunk <bunk@stusta.de>]

On Thu, Jul 21, 2005 at 11:06:22PM -0400, Chuck Ebbert wrote:
> 
>   This patch makes restore_fpu() an inline.  When L1/L2 cache are saturated
> it makes a measurable difference.
> 
>   Results from profiling Volanomark follow.  Sample rate was 2000 samples/sec
> (HZ = 250, profile multiplier = 8) on a dual-processor Pentium II Xeon.
> 
> 
> Before:
> 
>  10680 restore_fpu                              333.7500
>   8351 device_not_available                     203.6829
>   3823 math_state_restore                        59.7344
>  -----
>  22854
> 
> 
> After:
> 
>  12534 math_state_restore                       130.5625
>   8354 device_not_available                     203.7561
>  -----
>  20888
> 
> 
> Patch is "obviously correct" and cuts 9% of the overhead.  Please apply.
>...

If this patch makes a difference, could you do me a favour and check 
whether replacing the current cpu_has_fxsr #define in
include/asm-i386/cpufeature.h with

  #define cpu_has_fxsr           1

on top of your patch brings an additional improvement?

> Chuck

TIA
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed