From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [RFC PATCH 0/7] Add MMC packed function Date: Mon, 12 Aug 2019 11:58:00 +0300 Message-ID: <8abff7d6-0a3e-efe7-e8ec-9309fada9121@intel.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Baolin Wang , Jens Axboe , Ulf Hansson Cc: Chunyan Zhang , Orson Zhai , Arnd Bergmann , Linus Walleij , Vincent Guittot , linux-mmc , LKML , linux-block@vger.kernel.org List-Id: linux-mmc@vger.kernel.org On 12/08/19 8:20 AM, Baolin Wang wrote: > Hi, > > On Mon, 22 Jul 2019 at 21:10, Baolin Wang 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? >> >> 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?