Chris,

Right, without the patch I get..

[   52.526665] mmc0: new SDHC card at address e624
[   52.571228] mmcblk0: mmc0:e624 SD16G 14.8 GiB
[   52.591071] mmcblk0: retrying using single block read
[   52.593105] mmcblk0: error -84 transferring data, sector 0, nr 8, card 
status 0x900
[   52.593109] end_request: I/O error, dev mmcblk0, sector 0
[   52.594594] mmcblk0: error -84 transferring data, sector 1, nr 7, card 
status 0x900
[   52.594604] end_request: I/O error, dev mmcblk0, sector 1
[   52.602893] quiet_error: 24 callbacks suppressed
[   52.602902] Buffer I/O error on device mmcblk0, logical block 0
[   52.605349] ldm_validate_partition_table(): Disk read failed.
[   52.605384] Dev mmcblk0: unable to read RDB block 0
[   52.607729]  mmcblk0: unable to read partition table
u@u:~$

So, I cannot generate any comparison data with this SD card.

On Mon, 18 Jul 2011, Chris Ball wrote:

> Hi Manoj,
>
> On Mon, Jul 18 2011, Manoj Iyer wrote:
>> Here are the results with SanDisk SDSDXP1-016G-A75 16GB Extreme Pro
>> SDHC Memory Card.
>>
>> u@u:~/flashbench$ sudo ./flashbench -a /dev/mmcblk0p1
>> [sudo] password for u:
>> align 4294967296        pre 1.16ms      on 1.15ms       post 1.15ms
>> diff -2024ns
>> align 2147483648        pre 1.2ms       on 1.2ms        post 1.2ms
>> diff 522ns
>> align 1073741824        pre 1.21ms      on 1.2ms        post 1.2ms
>> diff 570ns
>> align 536870912 pre 1.2ms       on 1.2ms        post 1.2ms      diff 662ns
>> align 268435456 pre 1.2ms       on 1.2ms        post 1.2ms      diff 404ns
>> align 134217728 pre 1.2ms       on 1.2ms        post 1.2ms      diff
>> -1692ns
>> align 67108864  pre 1.15ms      on 1.16ms       post 1.16ms     diff
>> 1.37µs
>> align 33554432  pre 1.18ms      on 1.19ms       post 1.15ms     diff
>> 31.3µs
>> align 16777216  pre 1.17ms      on 1.19ms       post 1.15ms     diff
>> 31.5µs
>> align 8388608   pre 1.17ms      on 1.21ms       post 1.18ms     diff
>> 32.9µs
>> align 4194304   pre 1.37ms      on 1.55ms       post 1.17ms     diff 274µs
>> align 2097152   pre 1.37ms      on 1.37ms       post 1.39ms     diff
>> -7992ns
>> align 1048576   pre 1.33ms      on 1.33ms       post 1.34ms     diff
>> -7793ns
>> align 524288    pre 1.33ms      on 1.33ms       post 1.34ms     diff
>> -6641ns
>> align 262144    pre 1.34ms      on 1.38ms       post 1.35ms     diff
>> 33.8µs
>> align 131072    pre 1.35ms      on 1.37ms       post 1.34ms     diff
>> 27.2µs
>> align 65536     pre 1.34ms      on 1.37ms       post 1.34ms     diff
>> 31.7µs
>> align 32768     pre 1.33ms      on 1.37ms       post 1.34ms     diff
>> 32.5µs
>>
>> u@u:~/flashbench$ sudo ./flashbench -O --erasesize=$[4 * 1024 * 1024]
>> --blocksize=$[256 * 1024] /dev/mmcblk0p1 --open-au-nr=2
>> 4MiB    23.2M/s
>> 2MiB    23.6M/s
>> 1MiB    23.5M/s
>> 512KiB  23.2M/s
>> 256KiB  23.2M/s
>> u@u:~/flashbench$
>
> I don't understand whether these measurements are before or after your
> patch -- we're looking to see what the *difference* in performance is
> with the patch applied, right?
>
> Thanks,
>
> - Chris.
> -- 
> Chris Ball   <cjb@laptop.org>   <http://printf.net/>
> One Laptop Per Child
>
>

--
====================
Manoj Iyer
Ubuntu/Canonical
Hardware Enablement
====================