lkml.org 
[lkml]   [2005]   [Apr]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [patch] sched: auto-tune migration costs [was: Re: Industry db benchmark result on recent 2.6 kernels]
Date
Ingo Molnar wrote on Monday, April 04, 2005 8:05 PM
>
> latest patch attached. Changes:
>
> - stabilized calibration even more, by using cache flushing
> instructions to generate a predictable working set. The cache
> flushing itself is not timed, it is used to create quiescent
> cache state.
>
> I only guessed the ia64 version - e.g. i didnt know what 'type'
> argument to pass to ia64_sal_cache_flush() to get a d/cache
> flush+invalidate.

It is preferable to use a ia64_pal_cache_flush instead of SAL call. But
it hangs the machine with that pal call. I will look at it tomorrow.
The type argument for sal_cache_flush is: 1 for icache, 2 for dcache,
and 3 for i+d.


> - due to more stable results, reduced ITERATIONS from 3 to 2 - this
> should further speed up calibration.
>
> tested on x86, the calibration results look ok there.

Calibration result on ia64 (1.5 GHz, 9 MB), somewhat smaller in this
version compare to earlier estimate of 10.4ms. The optimal setting
found by a db workload is around 16 ms.

---------------------
| migration cost matrix (max_cache_size: 9437184, cpu: -1 MHz):

---------------------
[00] [01] [02] [03]
[00]: - 9.3(0) 9.3(0) 9.3(0)
[01]: 9.3(0) - 9.3(0) 9.3(0)
[02]: 9.3(0) 9.3(0) - 9.3(0)
[03]: 9.3(0) 9.3(0) 9.3(0) -
--------------------------------
| cacheflush times [1]: 9.3 (9329800)
| calibration delay: 16 seconds
--------------------------------


-
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/

\
 
 \ /
  Last update: 2005-04-06 13:31    [W:0.068 / U:1.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site