100% CPU issue RT-N66U

[Schmeckles23]

Hello,

I am downloading GTA 5 and I realised in the web panel I am getting 100% CPU and its not as responsive. I have logged into SSH and here are the stats.

I am on a 300MB WAN connection and the download is hitting 15Mb/s.

Top stats -

PID  PPID USER     STAT   VSZ %VSZ CPU %CPU COMMAND
  859     1 nathan   R     4752  1.9   0 51.9 httpd -i br0
  236     1 nathan   R     1524  0.6   0 22.8 /usr/sbin/acsd
  864   837 nathan   S     1184  0.4   0 14.0 dropbear -p 192.168.1.1:22 -j -k
  222     1 nathan   S     4992  2.0   0  3.7 /sbin/wanduck
    3     2 nathan   RWN      0  0.0   0  3.2 [ksoftirqd/0]

httpd is not always the only process that I get high CPU on, it's sometimes
/usr/sbin/acsd
and
/bin/eapd

If I do a speedtest at Speedtest.net I don't get high CPU it only seems to be certain downloaders.

 

[Schmeckles23]

Any light on this guys?

 

[Nullity]

15Mbyte/sec wirelessly? That's practically the limit of what your router is capable of, so a high cpu load is normal.

 

[captb3nder]

Hey, I'm having the same problems with the same router. Running latest Merlin (not beta). QoS is turned off (though happens either way). I seem to have localized the CPU usage spiking when I have heavy downloads or 4k Netflix streaming (that won't reach 100%, but still high). All wired devices. Checked top while transferring from my NAS to my computer at 30 MB/s and top never got over 1% utilization. So it does seem to be internet related.

For instance, if I run a speedtest which takes up my 100/15 pipe, it'll spike at 100%. The UI becomes sluggish, if not unusable. I have top running and it won't update as frequently. It is hard to get the process because it's not updating.

Results from top testing:

This had 99.1% sirq):
29% miniupnpd -f /etc/upnp/config
16% [events/0]
13.5% [ksoftirqd/0]
8.7% /usr/sbin/acsd
6.3% /sbin/wanduck
4% dropbear -p <ip> -j -k

This had 80.7% sirq:
22.6% dnsmasq --log-async
20% /usr/sbin/acsd
8% miniupnpd -f /etc/upnp/config
6.1% /bin/wps_monitor
5.2% [ksoftirqd/0]

This had 87.6% sirq
22.1% /bin/eapd
15.8%/usr/sbin/acsd
9% /sbin/wanduck
3.8% [ksoftirqd/0]


Thanks!

 

[RMerlin]

This had 99.1% sirq):

SIRQ is typically traffic getting routed. You are simply reaching the limit your RT-N66U can handle in terms of throughput.

 

[captb3nder]

Thanks for the prompt response. I was having a difficult time finding information on sirq. That's what I was afraid it was.

 

[captb3nder]

For anyone that may stumble upon this thread, I've been able to reduce my SIRQ % by taking the following steps. I don't know if any one specific thing worked and this hasn't been proven out long term.

NAT Acceleration > Auto (was previously disabled)
WPS > Disabled

I ran several speed tests including 2 at once and SIRQ never got over 20%. I'll run with this a for a few days. Hopefully this helped to reduce my routing overhead.