On Tue, May 5, 2020 at 1:46 AM Václav Zindulka <vaclav.zindu...@tlapnet.cz> wrote: > > On Mon, May 4, 2020 at 7:46 PM Cong Wang <xiyou.wangc...@gmail.com> wrote: > > > > Sorry for the delay. I lost connection to my dev machine, I am trying > > to setup this on my own laptop. > > Sorry to hear that. I will gladly give you access to my testing > machine where all this nasty stuff happens every time so you can test > it in place. You can try everything there and have online results. I > can give you access even to the IPMI console so you can switch the > kernel during boot easily. I didn't notice this problem until the time > of deployment. My prior testing machines were with metallic ethernet > ports only so I didn't know about those problems earlier.
Thanks for the offer! No worries, I setup a testing VM on my laptop. > > > On Mon, May 4, 2020 at 10:36 PM Cong Wang <xiyou.wangc...@gmail.com> wrote: > > > > > > Regarding to your test result above, I think I saw some difference > > > on my side, I have no idea why you didn't see any difference. Please > > > let me collect the data once I setup the test environment shortly today. > > I saw some improvement too. It was more than 1.5s faster. Yet it was > still over 21s. I measured it with perf trace, not with time. I'll try > it the same way as you did. > > > > > I tried to emulate your test case in my VM, here is the script I use: > > > > ==== > > ip li set dev dummy0 up > > tc qd add dev dummy0 root handle 1: htb default 1 > > for i in `seq 1 1000` > > do > > tc class add dev dummy0 parent 1:0 classid 1:$i htb rate 1mbit ceil > > 1.5mbit > > tc qd add dev dummy0 parent 1:$i fq_codel > > done > > > > time tc qd del dev dummy0 root > > ==== > > > > And this is the result: > > > > Before my patch: > > real 0m0.488s > > user 0m0.000s > > sys 0m0.325s > > > > After my patch: > > real 0m0.180s > > user 0m0.000s > > sys 0m0.132s > > My results with your test script. > > before patch: > /usr/bin/time -p tc qdisc del dev enp1s0f0 root > real 1.63 > user 0.00 > sys 1.63 > > after patch: > /usr/bin/time -p tc qdisc del dev enp1s0f0 root > real 1.55 > user 0.00 > sys 1.54 > > > This is an obvious improvement, so I have no idea why you didn't > > catch any difference. > > We use hfsc instead of htb. I don't know whether it may cause any > difference. I can provide you with my test scripts if necessary. Yeah, you can try to replace the htb with hfsc in my script, I didn't spend time to figure out hfsc parameters. My point here is, if I can see the difference with merely 1000 tc classes, you should see a bigger difference with hundreds of thousands classes in your setup. So, I don't know why you saw a relatively smaller difference. Thanks.
