Re: [RFC] IO scheduler based IO controller V6

From: Gui Jianfeng
Date: Mon Jul 27 2009 - 23:38:30 EST


Vivek Goyal wrote:
> On Mon, Jul 27, 2009 at 08:55:03AM -0400, Vivek Goyal wrote:
>> On Mon, Jul 27, 2009 at 10:10:34AM +0800, Gui Jianfeng wrote:
>>> Hiï
>>>
>>> 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.
>>
>
> Gui, can you also try with CONFIG_TRACK_ASYNC_CONTEXT=n and see if it improves
> buffered write performance.

Hi Vivek,

Ok, I'll do it, and i'll do the performance test for IO Controller V7, and post
the results as soon as i get them.

>
> Thanks
> Vivek
>
>> 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.
>>
>> Is it also possible to run the same tests with V7.
>>
>> Thanks
>> Vivek
>>
>>> Arch: X86
>>> Mem: 1G
>>> Disk: 320G
>>> IO Scheduler: CFQ
>>>
>>> ============
>>> By normal read and write syscall.
>>>
>>> Block Size:32K
>>> File Size: 1G * 10
>>>
>>> Mode Normal read | Random read | Normal write | Random write | Direct read | Direct write
>>>
>>> 2.6.31-rc1 47,932KiB/s 3,566KiB/s 45,693KiB/s 8,501KiB/s 50,088KiB/s 43,473KiB/s
>>>
>>> 2.6.31-rc1-Vivek-V6 47,231KiB/s 3,411KiB/s 42,451KiB/s 8,714KiB/s 51,284KiB/s 42,341KiB/s
>>>
>>> Performance -1.5% -4.4% -7.0% +2.5% +2.4% -2.6%
>>>
>>> ============
>>>
>>> By mmap.
>>>
>>> Block Size:32K
>>> File Size: 500M
>>>
>>> Mode Normal read | Random read | Normal write | Random write
>>>
>>> 2.6.31-rc1 49,951KiB/s 3,245KiB/s 21,950KiB/s 2,771KiB/s
>>>
>>> 2.6.31-rc1-Vivek-V6 49,951KiB/s 3,154KiB/s 22,593KiB/s 2,648KiB/s
>>>
>>> Performance 0% -2.8% +2.9% -4.4%
>>>
>>> ============
>>>
>>> By libaio calls
>>>
>>> Block Size:32K
>>> File Size: 500M
>>>
>>> Mode Normal read | Random read | Normal write | Random write
>>>
>>> 2.6.31-rc1 49,447KiB/s 3,296KiB/s 57,519KiB/s 21,093KiB/s
>>>
>>> 2.6.31-rc1-Vivek-V6 50,142KiB/s 3,238KiB/s 57,791KiB/s 21,283KiB/s
>>>
>>> Performance +1.4% -1.8% 0% +0.1%
>>>
>>> ============
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
>

--
Regards
Gui Jianfeng

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