Download limit problem

[davidkek]

Hi all

i have problem with set speed over 50mb/s

iptables -A FORWARD -m ratelimit --ratelimit-set up --ratelimit-mode src -j DROP
iptables -A FORWARD -m ratelimit --ratelimit-set down --ratelimit-mode dst -j DROP
echo / > /proc/net/ipt_ratelimit/up
echo / > /proc/net/ipt_ratelimit/down
echo +192.168.0.2 100000000 > /proc/net/ipt_ratelimit/up
echo +192.168.0.2 100000000 > /proc/net/ipt_ratelimit/down

192.168.0.2 cir 104857600 cbs 19660800 ebs 39321600; tc 0 te 0 last never; conf 0/0 0 bps, rej 0/0

problem is come when i try to set 70,80,90,100 mbit speed is limit to 8-10 mbit
after back shaper to 50 mbit is work fine shape customer to 50-52mb/s

how to debug this problem and to fix.

[aabc]

Hello. What is HZ value for your kernel? Try command zcat /proc/config.gz | grep CONFIG_HZ.

[aabc]

Please, better do zcat /proc/config.gz | grep _HZ, I want to see NO_HZ values too.

[davidkek]

Hi

CONFIG_NO_HZ_COMMON=y

CONFIG_NO_HZ_IDLE is not set

CONFIG_NO_HZ_FULL=y

CONFIG_NO_HZ is not set

CONFIG_RCU_FAST_NO_HZ=y

CONFIG_HZ_PERIODIC is not set

CONFIG_HZ_100=y

CONFIG_HZ_250 is not set

CONFIG_HZ_300 is not set

CONFIG_HZ_1000 is not set

CONFIG_HZ=100

this is a set of HZ config
and server work very fine
do you need to change from 100hz

[davidkek]

I try to reproduce in second lab system but not success
and wait to try with other device to see is have the problem or not .

[aabc]

Thanks. You may try to set higher HZ value, like 250 (reported to work good) or even more. Speed limiting arithmetic is 32-bit, so it could overflow with small HZ.

[davidkek]

did you think to remake it for 64bit.
however, it is more modern and more functional.
I know that I will have to redo not a small part of the code, but if I have to I will help.

[davidkek]

however, all new devices are 64bit and will be much more functional.

[aabc]

Also, CONFIG_NO_HZ_FULL=y I am not sure atm how that would affect speed calculation. It reported to work good on CONFIG_NO_HZ_IDLE=y though.

[davidkek]

i will try move to 250Hz and will test CONFIG_NO_HZ_IDLE=y

but in last test i prefer 100Hz and CONFIG_NO_HZ_FULL system work very stable and with low load .

[aabc]

did you think to remake it for 64bit.

Yes, probably, I should.

[davidkek]

i will wait this changes! they will certainly work much better.

[aabc]

i will try move to 250Hz and will test CONFIG_NO_HZ_IDLE=y

I would appreciate such test!

[davidkek]

Hi i am back
now i compile kernel on 250Hz and CONFIG_NO_HZ_IDLE=y

but the problem is hear and i find solution :)
when customer is set to 70Mbit or more now i test with 100mbit limit .
if machine is in idle and have 1 customer shaper and try speed test or other download from internet customer go to max 20mb/s from 15-20Mb/s
after run load software to load 2-3 cpu or more of the server shaper start work

Upload limit is fine
Only download limit have a problem .
without cpu load on server customer get 1 or 2 time 100mbit and after that get only from 8-20mb/s
after run cpu load software 3-4 cpus shaper start work fine 100 of 100mbit get on customer machine.

Very strange... machine run kernel 5.8.14 kernel and very clean image.
This is cpu : Intel(R) Xeon(R) CPU E5-1650 v4 @ 3.60GHz
Ethernet :
02:00.0 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01)
02:00.1 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01)

[aabc]

I think you should test locally (in local network), for example with iperf between two servers - not relying on customer reports or third-party internet speed testing services. If local test is correct, (and you say upload is ok), then ipt-ratelimit is working correctly and you, probably, have some other problems. If you measure between distant endpoints in Internet a lot of factors could affect the speed.