[dm-devel] Re: [RFC] IO scheduler based IO controller V6

[Gui Jianfeng]

Vivek Goyal wrote:
> On Mon, Jul 27, 2009 at 10:10:34AM +0800, Gui Jianfeng wrote:
>> Hi，
>>
>> Here are some fio test results for IO Controller V6 built and not built.
>> Iozone test results are also attached.
>>
> 
> Hi Gui,
> 
> Thanks a lot for some performance numbers. It seems to be a mixed chart.
> Performance gains at some places and loss at others. I am curious about
> that -7.0% for normal writes. Not sure what can contribute to that.
> 
> What was the value of "fairness" parameter when you ran those tests? Can you
> please set fairness = 0 and re-run the tests (if you have already not done so).
> 
> By default fairness is set to 1 in V6. With fairness = 0, we should be very
> close to existing CFQ behavior. If not, then we need to dive deeper and
> see why variations are happening.

  Hi Vivek,

  I tested with default fairness value, i'll re-test it when fairness is set to 0.

> 
> Is it also possible to run the same tests with V7. 

  Sure.

-- 
Regards
Gui Jianfeng