Hi Adrian, On Mon, 12 Aug 2019 at 17:44, Baolin Wang <baolin.wang@xxxxxxxxxx> 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. I've checked my hardware and did not find any problem. The reason of low speed is that I set the bs = 4k, when I changed the bs=1M, and the speed can go up to 251MiB/s. ./fio --filename=/dev/mmcblk0p30 --direct=1 --iodepth=20 --rw=read --bs=1M --size=512M --group_reporting --numjobs=20 --name=test_read READ: bw=251MiB/s (263MB/s), 251MiB/s-251MiB/s (263MB/s-263MB/s), io=10.0GiB (10.7GB), run=40826-40826msec -- Baolin Wang Best Regards
