Re: [RFC/PATCH 0/2] ROW scheduling Algorithm

[Jaehoon Chung <jh80.chung@samsung.com>]

On 08/08/2012 07:37 PM, Tanya Brokhman wrote:
> Hi Chung
> 
>> Hi
>>
>> I tested with this patch on my board.
>> But i didn't get any performance benefit.
>> Which benchmark did you use?
> 
> As I already mentioned I used lmdd. The results I published were collected using the bellow command run in parallel:
> adb shell /data/lmdd if=internal of=/data/writefile bs=128k count=3000
> adb shell /data/lmdd if=/data/readfile of=internal bs=128k count=3000
> 
> With lmdd we did see great improvement both in throughput and in read latency:
> CFQ:	     READ  20.81 MB/sec,    WRITE  15.23 MB/sec   Worst case READ latency 230 msec     Worst case write latency   9370   msec
> ROW:         READ  27.75 MB/sec      WRITE  15.34 MB/sec   Worst case READ latency   85 msec     Worst case write latency   12025 msec
> 
> ROW can be configured to perform at ~34 MB/sec throughput in the above scenario but in this configuration worst case write latency increases to ~13 sec.
I will try to test with lmdd.
> 
>> And sometime this scheduler didn't work well read/write operation.
>> (i didn't know exactly what problem.)
> 
> This may be. We're still working on testing the scheduler and improving it. It's not yet totally "bug free". I've uploaded the code as RFC. 
> 
>>
>> The below is my environment:
>> Kernel Version: linux-3.4
>> Card: eMMC4.5 (50MHz DDR mode, 8-bit buswidth) Host controller : dw-
>> mmc (DesignWare MMC controller) Benchmark : IOzone
>>
> 
> My environment is similar except the host controller which is msm-sdcc. 
> Could you please give me the exact iozone command you used? I'll replay it on my setup.
iozone -A -s 200m -U /data/ -f /data/test -e and iozone -A -s 200m -f /data/test -e -I

Best Regards,
Jaehoon Chung
> 
> Thanks,
> Tanya Brokhman
> ---
> Sent by an consultant of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
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