Re: [PATCH v5 2/2] mmc: core: Support packed command for eMMC4.5 device

[Namjae Jeon]

Hi. merez.

Would you share random read speed with us ?

And Write speed also..

Thanks.

2012/3/1  <merez@xxxxxxxxxxxxxx>:
>> This patch supports packed command of eMMC4.5 device.
>> Several reads(or writes) can be grouped in packed command
>> and all data of the individual commands can be sent in a
>> single transfer on the bus.
>>
>> Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
>> ---
>> Âdrivers/mmc/card/block.c  | Â496
>> +++++++++++++++++++++++++++++++++++++++++--
>> Âdrivers/mmc/card/queue.c  |  48 ++++-
>> Âdrivers/mmc/card/queue.h  |  13 ++
>> Âdrivers/mmc/core/mmc_ops.c | Â Â1 +
>> Âinclude/linux/mmc/core.h  |  Â4 +
>> Â5 files changed, 535 insertions(+), 27 deletions(-)
>>
> Hi,
>
> We ran performance tests on the packed commands patch. We found out that
> enabling the read packing didn't improve the performance in any of the
> scenarios we ran (see the detailed results below).
> Therefore, we suggest to move the read packing code to a different patch
> and approve only the write packing code for now. The read packing adds
> complexity to the code and we don't see a point in adding it while the
> intention is to disable it.
>
> Test results:
>
> Long read operation:
> ----------------------
> no-packing: 39.5 MB/s
> packed commands patch (both READ and WRITE packing are enabled): 39.5 MB/s
> packed commands patch + enabling only READ packing: 39.5 MB/s
>
> Several parallel read operations (sum of all the read throughputs):
> ---------------------------
> no-packing: 42.6 MB/s
> packed commands patch(both READ and WRITE packing are enabled): 38 MB/s
> packed commands patch + enabling only READ packing: 38.2 MB/s
>
> Parallel long read and long write operations (read throughput):
> -----------------------------------------------------------------
> no-packing: 23.8 MB/s
> packed commands patch (both READ and WRITE packing are enabled): 12.6 MB/s
> packed commands patch + enabling only READ packing: 12.5 MB/s
>
> Parallel short read and long write operations (read throughput):
> -----------------------------------------------------------------
> no-packing: 22.9 MB/s
> packed commands patch (both READ and WRITE packing are enabled): 8.4 MB/s
> packed commands patch + enabling only READ packing: 8.6 MB/s
>
> Several Parallel short read and short write operations (sum of all the
> read throughputs):
> --------------------------------------------------------------------------
> no-packing: 41.6 MB/s
> packed commands patch (both READ and WRITE packing are enabled): 35 MB/s
> packed commands patch + enabling only READ packing: 36 MB/s
>
> Thanks,
> Maya Erez
> Consultant for Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
>
>
>
>
>
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