> Il giorno 2 set 2019, alle ore 17:56, Tejun Heo <tj@xxxxxxxxxx> ha scritto: > > On Mon, Sep 02, 2019 at 05:45:50PM +0200, Paolo Valente wrote: >> Thanks for this extra explanations. It is a little bit difficult for >> me to understand how the min/max teaks for exactly, but you did give >> me the general idea. > > It just limits how far high and low the IO issue rate, measured in > cost, can go. ie. if max is at 200%, the controller won't issue more > than twice of what the cost model says 100% is. > >> Are these results in line with your expectations? If they are, then >> I'd like to extend benchmarks to more mixes of workloads. Or should I >> try some other QoS configuration first? > > They aren't. Can you please include the content of io.cost.qos and > io.cost.model before each run? Note that partial writes to subset of > parameters don't clear other parameters. > Yep. I've added the printing of the two parameters in the script, and I'm pasting the whole output, in case you could get also some other useful piece of information from it. $ sudo ./bandwidth-latency.sh -t randread -s none -b weight -n 7 -d 20 Switching to none for sda echo "8:0 enable=1 rpct=95 rlat=2500 wpct=95 wlat=5000" > /cgroup/io.cost.qos /cgroup/io.cost.qos 8:0 enable=1 ctrl=user rpct=95.00 rlat=2500 wpct=95.00 wlat=5000 min=1.00 max=10000.00 /cgroup/io.cost.model 8:0 ctrl=auto model=linear rbps=488636629 rseqiops=8932 rrandiops=8518 wbps=427891549 wseqiops=28755 wrandiops=21940 Not changing weight/limits for interferer group 0 Not changing weight/limits for interferer group 1 Not changing weight/limits for interferer group 2 Not changing weight/limits for interferer group 3 Not changing weight/limits for interferer group 4 Not changing weight/limits for interferer group 5 Not changing weight/limits for interferer group 6 Not changing weight/limits for interfered Starting Interferer group 0 start_fio_jobs InterfererGroup0 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile0 Starting Interferer group 1 start_fio_jobs InterfererGroup1 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile1 Starting Interferer group 2 start_fio_jobs InterfererGroup2 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile2 Starting Interferer group 3 start_fio_jobs InterfererGroup3 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile3 Starting Interferer group 4 start_fio_jobs InterfererGroup4 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile4 Starting Interferer group 5 start_fio_jobs InterfererGroup5 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile5 Starting Interferer group 6 start_fio_jobs InterfererGroup6 0 default read MAX linear 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile6 Linux 5.3.0-rc6+ (paolo-ThinkPad-W520) 02/09/2019 _x86_64_ (8 CPU) 02/09/2019 21:39:11 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 66.53 5.22 0.10 1385 27 start_fio_jobs interfered 20 default randread MAX poisson 1 1 0 0 4k /home/paolo/local-S/bandwidth-latency/../workfiles/largefile_interfered0 02/09/2019 21:39:14 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 154.67 20.63 0.05 61 0 02/09/2019 21:39:17 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 453.00 64.27 0.00 192 0 02/09/2019 21:39:20 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 675.33 95.99 0.00 287 0 02/09/2019 21:39:23 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 1907.67 348.61 0.00 1045 0 02/09/2019 21:39:26 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 2414.67 462.98 0.00 1388 0 02/09/2019 21:39:29 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 2429.67 438.71 0.00 1316 0 02/09/2019 21:39:32 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 2437.00 475.79 0.00 1427 0 02/09/2019 21:39:35 Device tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 2162.33 346.97 0.00 1040 0 Results for one rand reader against 7 seq readers (I/O depth 1), weight-none with weights: (default, default) Aggregated throughput: min max avg std_dev conf99% 64.27 475.79 319.046 171.233 1011.97 Read throughput: min max avg std_dev conf99% 64.27 475.79 319.046 171.233 1011.97 Write throughput: min max avg std_dev conf99% 0 0 0 0 0 Interfered total throughput: min max avg std_dev 1.032 4.455 2.266 0.742696 Interfered per-request total latency: min max avg std_dev 0.11 12.005 1.7545 0.878281 Thanks, Paolo > Thanks. > > -- > tejun