On Mon, 12 Aug 2019 at 18:52, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: > > On 12/08/19 12:44 PM, Baolin Wang wrote: > > Hi Adrian, > > > > On Mon, 12 Aug 2019 at 16:59, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: > >> > >> On 12/08/19 8:20 AM, Baolin Wang wrote: > >>> 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 > >> > >> This seems surprising low for a HS400ES card. Do you know why that is? > > > > I've set the clock to 400M, but it seems the hardware did not output > > the corresponding clock. I will check my hardware. > > > >>>> > >>>> 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. > >> > >> Did you consider adapting the CQE interface? > > > > I am not very familiar with CQE, since my controller did not support > > it. But the MMC packed function had introduced some callbacks to help > > for different controllers to do packed request, so I think it is easy > > to adapt the CQE interface. > > > > I meant did you consider using the CQE interface instead of creating another > one? Sorry for misunderstanding. I think the core/core.c modification can use the CQE interface, but there are some difference in core/block.c, and I think they are different mechanisms, also I want to keep avoid affecting CQE and normal transfer, so I think adding MMC packed related interfaces will be easy to read and maintain. -- Baolin Wang Best Regards
