On 10/19/22 19:45, Wenchao Chen wrote: > From: Wenchao Chen <wenchao.chen@xxxxxxxxxx> > > This patch introduces host->fua_disable for MMC host controller. > The host can turn off FUA to improve performance. > > 1. fua_disable = 1 > /sys/block/mmcblk0/queue # cat fua 0 > I tested 5 times for each case and output a average speed. > > 1) Sequential read: > Speed: 266.8MiB/s, 265.1MiB/s, 262.9MiB/s, 268.7MiB/s, 265.2MiB/s > Average speed: 265.74MiB/s > > 2) Random read: > Speed: 98.75MiB/s, 98.7MiB/s, 98.5MiB/s, 99.4MiB/s, 98.7MiB/s > Average speed: 98.81MiB/s > > 3) Sequential write: > Speed: 199.94MiB/s, 199.1MiB/s, 205.5MiB/s, 206.5MiB/s, 191.5MiB/s > Average speed: 200.5MiB/s > > 4) Random write: > Speed: 68.6MiB/s, 71.8MiB/s, 77.1MiB/s, 64.8MiB/s, 69.3MiB/s > Average speed: 70.32MiB/s > > 2. fua_disable = 0 (default 0) > /sys/block/mmcblk0/queue # cat fua 1 > I tested 5 times for each case and output a average speed. > > 1) Sequential read: > Speed: 259.3MiB/s, 258.8MiB/s, 258.2MiB/s, 259.5MiB/s, 253.5MiB/s > Average speed: 257.86MiB/s > > 2) Random read: > Speed: 98.9MiB/s, 101MiB/s, 101MiB/s, 99MiB/s, 101.1MiB/s > Average speed: 100.2MiB/s > > 3) Sequential write: > Speed: 153.7MiB/s, 146.2MiB/s, 151.2MiB/s, 148.8MiB/s, 147.5MiB/s > Average speed: 149.48MiB/s > > 4) Random write: > Speed: 12.9MiB/s, 12.3MiB/s, 12.6MiB/s, 12.8MiB/s, 12.8MiB/s > Average speed: 12.68MiB/s > > According to the above data, disable FUA (fua_disable = 1) improves the > performance. Therefore, it is recommended to support the host to control > FUA. > > Signed-off-by: Wenchao Chen <wenchao.chen@xxxxxxxxxx> Based on the data provided seems it does increase the performance. Perhaps it is worth mentioning the reason behind the performance increase and other side effects of doing so ? Also, it is usually helpful to mention performance increase in the % in the commit log so you can move verbose log (like above) into the cover-letter for documentation purpose, this is based on the feedback I got, unless maintainer(s) prefers is this way :). -ck
