Re: fio posixaio performance problem

[Gui Jianfeng]

On 2011-8-3 15:38, Shaohua Li wrote:
> 2011/8/3 Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>:
>> Hi,
>>
>> I ran a fio test to simulate qemu-kvm io behaviour.
>> When job number is greater than 2, IO performance is
>> really bad.
>>
>> 1 thread: aggrb=15,129KB/s
>> 4 thread: aggrb=1,049KB/s
>>
>> Kernel: lastest upstream
>>
>> Any idea?
>>
>> ---
>> [global]
>> runtime=30
>> time_based=1
>> size=1G
>> group_reporting=1
>> ioengine=posixaio
>> exec_prerun='echo 3 > /proc/sys/vm/drop_caches'
>> thread=1
>>
>> [kvmio-1]
>> description=kvmio-1
>> numjobs=4
>> rw=write
>> bs=4k
>> direct=1
>> filename=/mnt/sda4/1G.img
> Hmm, the test runs always about 15M/s at my side regardless how many threads.

CFQï
what's the slice_idle value?

Thanks,
Gui

> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 
> 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/