Re: CFQ IO scheduler patch series - AIM7 DBase results on a 16-way IA64

["Alan D. Brunelle" <Alan.Brunelle@hp.com>]

Jens Axboe wrote:
> On Mon, Apr 30 2007, Alan D. Brunelle wrote:
>> The results from a single run of an AIM7 DBase load on a 16-way ia64 box 
>> (64GB RAM + 144 FC disks) showed a slight regression (~0.5%) by adding 
>> in this patch. (Graph can be found at   
>> http://free.linux.hp.com/~adb/cfq/cfq_dbase.png   ) It is only a single 
>> set of runs, on a single platform, but it is something to keep an eye on 
>> as the regression showed itself across the complete run.
>
> Do you know if this regression is due to worse IO performance, or
> increased system CPU usage?
We performed two point runs yesterday (20,000 and 50,000 tasks) and here 
are the results:

Kernel  Tasks  Jobs per Minute  %sys (avg)
------  -----  ---------------  ----------
2.6.21  20000     60,831.1        39.83%
CFQ br  20000     60,237.4        40.80%
                    -0.98%        +2.44%

2.6.21  50000     60,881.6        40.43%
CFQ br  50000     60,400.6        40.80%
                    -0.79%        +0.92%

So we're seeing a slight IO performance regression with a slight 
increase in %system with the CFQ branch. (A chart of the complete run 
values is up on  http://free.linux.hp.com/~adb/cfq/cfq_20k50k.png  ).

Alan