Re: [RFC PATCH 0/7] Add MMC packed function

[Baolin Wang]

Hi,

On Mon, 22 Jul 2019 at 21:10, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
>
> Hi All,
>
> Now some SD/MMC controllers can support packed command or packed request,
> that means it can package multiple requests to host controller to be handled
> at one time, which can improve the I/O performence. Thus this patchset is
> used to add the MMC packed function to support packed request or packed
> command.
>
> In this patch set, I implemented the SD host ADMA3 transfer mode to support
> packed request. The ADMA3 transfer mode can process a multi-block data transfer
> by using a pair of command descriptor and ADMA2 descriptor. In future we can
> easily expand the MMC packed function to support packed command.
>
> Below are some comparison data between packed request and non-packed request
> with fio tool. The fio command I used is like below with changing the
> '--rw' parameter and enabling the direct IO flag to measure the actual hardware
> transfer speed.
>
> ./fio --filename=/dev/mmcblk0p30 --direct=1 --iodepth=20 --rw=read --bs=4K --size=512M --group_reporting --numjobs=20 --name=test_read
>
> My eMMC card working at HS400 Enhanced strobe mode:
> [    2.229856] mmc0: new HS400 Enhanced strobe MMC card at address 0001
> [    2.237566] mmcblk0: mmc0:0001 HBG4a2 29.1 GiB
> [    2.242621] mmcblk0boot0: mmc0:0001 HBG4a2 partition 1 4.00 MiB
> [    2.249110] mmcblk0boot1: mmc0:0001 HBG4a2 partition 2 4.00 MiB
> [    2.255307] mmcblk0rpmb: mmc0:0001 HBG4a2 partition 3 4.00 MiB, chardev (248:0)
>
> 1. Non-packed request
> I tested 3 times for each case and output a average speed.
>
> 1) Sequential read:
> Speed: 28.9MiB/s, 26.4MiB/s, 30.9MiB/s
> Average speed: 28.7MiB/s
>
> 2) Random read:
> Speed: 18.2MiB/s, 8.9MiB/s, 15.8MiB/s
> Average speed: 14.3MiB/s
>
> 3) Sequential write:
> Speed: 21.1MiB/s, 27.9MiB/s, 25MiB/s
> Average speed: 24.7MiB/s
>
> 4) Random write:
> Speed: 21.5MiB/s, 18.1MiB/s, 18.1MiB/s
> Average speed: 19.2MiB/s
>
> 2. Packed request
> In packed request mode, I set the host controller can package maximum 10
> requests at one time (Actually I can increase the package number), and I
> enabled read/write packed request mode. Also I tested 3 times for each
> case and output a average speed.
>
> 1) Sequential read:
> Speed: 165MiB/s, 167MiB/s, 164MiB/s
> Average speed: 165.3MiB/s
>
> 2) Random read:
> Speed: 147MiB/s, 141MiB/s, 144MiB/s
> Average speed: 144MiB/s
>
> 3) Sequential write:
> Speed: 87.8MiB/s, 89.1MiB/s, 90.0MiB/s
> Average speed: 89MiB/s
>
> 4) Random write:
> Speed: 90.9MiB/s, 89.8MiB/s, 90.4MiB/s
> Average speed: 90.4MiB/s
>
> Form above data, we can see the packed request can improve the performance greatly.
> Any comments are welcome. Thanks a lot.

Any comments for this patch set? Thanks.

>
> Baolin Wang (7):
>   blk-mq: Export blk_mq_hctx_has_pending() function
>   mmc: core: Add MMC packed request function
>   mmc: host: sdhci: Introduce ADMA3 transfer mode
>   mmc: host: sdhci: Factor out the command configuration
>   mmc: host: sdhci: Remove redundant sg_count member of struct
>     sdhci_host
>   mmc: host: sdhci: Add MMC packed request support
>   mmc: host: sdhci-sprd: Add MMC packed request support
>
>  block/blk-mq.c                |    3 +-
>  drivers/mmc/core/Kconfig      |    2 +
>  drivers/mmc/core/Makefile     |    1 +
>  drivers/mmc/core/block.c      |   71 +++++-
>  drivers/mmc/core/block.h      |    3 +-
>  drivers/mmc/core/core.c       |   51 ++++
>  drivers/mmc/core/core.h       |    3 +
>  drivers/mmc/core/packed.c     |  478 ++++++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/queue.c      |   28 ++-
>  drivers/mmc/host/Kconfig      |    1 +
>  drivers/mmc/host/sdhci-sprd.c |   22 +-
>  drivers/mmc/host/sdhci.c      |  513 +++++++++++++++++++++++++++++++++++------
>  drivers/mmc/host/sdhci.h      |   59 ++++-
>  include/linux/blk-mq.h        |    1 +
>  include/linux/mmc/core.h      |    1 +
>  include/linux/mmc/host.h      |    3 +
>  include/linux/mmc/packed.h    |  123 ++++++++++
>  17 files changed, 1286 insertions(+), 77 deletions(-)
>  create mode 100644 drivers/mmc/core/packed.c
>  create mode 100644 include/linux/mmc/packed.h
>
> --
> 1.7.9.5
>


-- 
Baolin Wang
Best Regards