Re: [PATCH 0/4] hw/sd: Improve performance of read/write/erase

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi Christian,

On 7/11/25 10:08, Christian Speich wrote:
> ping, I've not received any reaction on this series[1]. Is there anything I can do to
> move this forward?

My apologies for missing this... I was in PTO when you posted and then
it felt into my INBOX cracks :/

> On Fri, Sep 19, 2025 at 02:34:39PM +0200, Christian Speich wrote:
>> This patch series improves the performance of read/write/erase operations
>> on sdcards.
>>
>> This is done by increasing the maximum buffer size that is worked on.
>> >From 1 byte (master) to 512 bytes (first commit) to larger than 512
>> (adma commit).
>>
>> Testing on my system with fio I see the following rough performance
>> values in MiB/s.
>>
>>                read write readwrite
>>         master:   6     6     3/  3
>>   first commit:  51    43    23/ 23
>> second commit: 392   180   144/143
>>
>> Tested on a 2GiB raw image with:
>>    fio --filename=/dev/mmcblk0 --direct=1 --runtime=60 --time_based --bs=128k --rw={mode}
>>
>> The adma values are somewhat unstable but always >100MiB/s, I'm not sure
>> why but I guess it has something to do with the host side caching.
>>
>> For erasing the third commit changes the erase operation to write zeros,
>> as indicated by DATA_STAT_AFTER_ERASE in SCR.
>>
>> The fourth commit allows erasure in large blocks, to speed it up
>> significantly. Erasing 2GiB now takes 0.1s instead of 26s.
>>
>> Signed-off-by: Christian Speich <c.speich@avm.de>
>> ---
>> Christian Speich (4):
>>        hw/sd: Switch from byte-wise to buf+len read/writes
>>        hw/sd/sdhci: Don't use bounce buffer for ADMA
>>        hw/sd/sdcard: Erase blocks to zero
>>        hw/sd/sdcard: Erase in large blocks
>>
>>   hw/sd/core.c       |  16 +---
>>   hw/sd/sd.c         | 277 ++++++++++++++++++++++++++++++++++++++++-------------
>>   hw/sd/sdhci.c      | 102 +++++++++++---------
>>   include/hw/sd/sd.h |  13 +--
>>   4 files changed, 277 insertions(+), 131 deletions(-)
>> ---
>> base-commit: e7c1e8043a69c5a8efa39d4f9d111f7c72c076e6
>> change-id: 20250912-sdcard-performance-b4-d908bbb5a004
>>
>> Best regards,
>> -- 
>> Christian Speich <c.speich@avm.de>
>>
>>