On Thu 23-06-22 09:24:56, Damien Le Moal wrote: > On 6/21/22 19:24, Jan Kara wrote: > > Hello, > > > > This is the fourth revision of my patches fixing IO priority handling in the > > block layer. > > Hey, > > I ran some tests with RT IO class on an ATA HDD with NCQ priority. > Results look good: > > randread: (groupid=0, jobs=1): err= 0: pid=1862: Thu Jun 23 09:22:42 2022 > read: IOPS=152, BW=19.1MiB/s (20.0MB/s)(11.1GiB/592929msec) > slat (usec): min=37, max=3280, avg=174.96, stdev=120.90 > clat (msec): min=7, max=918, avg=156.95, stdev=149.43 > lat (msec): min=7, max=918, avg=157.13, stdev=149.43 > clat prio 0/0 (msec): min=7, max=918, avg=171.68, stdev=150.48 > clat prio 1/0 (msec): min=8, max=166, avg=24.64, stdev= 5.93 > clat percentiles (msec): > | 1.00th=[ 15], 5.00th=[ 20], 10.00th=[ 23], 20.00th=[ 32], > | 30.00th=[ 51], 40.00th=[ 77], 50.00th=[ 108], 60.00th=[ 146], > | 70.00th=[ 194], 80.00th=[ 262], 90.00th=[ 372], 95.00th=[ 477], > | 99.00th=[ 659], 99.50th=[ 701], 99.90th=[ 793], 99.95th=[ 818], > | 99.99th=[ 885] > clat prio 0/0 (89.99% of IOs) percentiles (msec): > | 1.00th=[ 15], 5.00th=[ 21], 10.00th=[ 27], 20.00th=[ 46], > | 30.00th=[ 68], 40.00th=[ 94], 50.00th=[ 126], 60.00th=[ 163], > | 70.00th=[ 213], 80.00th=[ 279], 90.00th=[ 388], 95.00th=[ 489], > | 99.00th=[ 659], 99.50th=[ 709], 99.90th=[ 793], 99.95th=[ 827], > | 99.99th=[ 885] > clat prio 1/0 (10.01% of IOs) percentiles (msec): > | 1.00th=[ 14], 5.00th=[ 17], 10.00th=[ 18], 20.00th=[ 20], > | 30.00th=[ 22], 40.00th=[ 23], 50.00th=[ 25], 60.00th=[ 26], > | 70.00th=[ 28], 80.00th=[ 30], 90.00th=[ 33], 95.00th=[ 35], > | 99.00th=[ 40], 99.50th=[ 42], 99.90th=[ 47], 99.95th=[ 50], > | 99.99th=[ 167] > > Clearly significantly lower tail latencies for the 10% of IOs with class > RT (1/0), as expected. This is with "none" scheduler at QD=24 (128K random > read). Nice! :) > Feel free to add: > > Tested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> Thanks for testing! I'll post the final patch version shortly. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
