Re: two NIC on 2 core system (scheduling problem)

Tuesday 28 of October 2008 12:29:54 Ivan Voras napisał(a):
Bartosz Giza wrote:
Tuesday 28 of October 2008 11:49:21 Oleksandr Samoylyk napisał(a):
Ivan Voras wrote:
Bartosz Giza wrote:
Another question is why em0 taskq is eating so much cpu ? BGE
interface is actually one that pushes 2 times more packets than em0
and it uses about half cpu comparing to em0. Is that not strange ?
Could someone tell my why is this happening ? BGE is faster ? or
maybe i can tune some

I have the same problem - em0 taskq eating incredible amounts of CPU.
If you find a solution, contact me!

It could be not just a problem with em driver.
Firstly, it's good to make profiling and find out what exactly eats
CPU time.

Yes, we should make some profiling, but it is quite hard on busy
production router. When i turn on pooling on em0 card swi1: net is
using about 3% of cpu. So it is quite big difference between 20% with
tasq and 3% with polling.

Is the difference reflected in your system / idle CPU time? (i.e. does
your idle time increase for ~~ 17%?)

Yes exactly my idle time is increasing ~17%
For now i am not using polling But i am preparing the same machine for much
more bussier router and i am not sure that this router with em cards will
suffice.
_______________________________________________
freebsd-net@xxxxxxxxxxx mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscribe@xxxxxxxxxxx"

Relevant Pages

  • Re: tuning for high connection rates
    ... outgoing traffic serving 4000 connections/sec using TCP. ... We are now running into some limits at peak time, system is up to 100% and em0 takes about 80% on one CPU while the Opentracker software only takes 10-15% CPU. ... Currently we are out of ideas for tuning, so we kindly ask for ideas on tuning the system to bring down the CPU usage from the em and the system CPU usage. ...
    (freebsd-performance)
  • Re: two NIC on 2 core system (scheduling problem)
    ... em0 and it uses about half cpu comparing to em0. ... Can you give any pointers on how to profile the driver and/or the ... you need options HWPMC_HOOKS and device hwpmc in your kernel config ...
    (freebsd-net)
  • Re: two NIC on 2 core system (scheduling problem)
    ... and it uses about half cpu comparing to em0. ... I have the same problem - em0 taskq eating incredible amounts of CPU. ... It could be not just a problem with em driver. ... it's good to make profiling and find out what exactly eats CPU ...
    (freebsd-net)
  • Re: Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp]
    ... Is it reporting the wrong cpu usage in TOP? ... packets errs bytes packets errs bytes colls ... em0: Excessive collisions = 0 ... Turning on polling.. ...
    (freebsd-net)
  • Re: two NIC on 2 core system (scheduling problem)
    ... and it uses about half cpu comparing to em0. ... I have the same problem - em0 taskq eating incredible amounts of CPU. ... vendor = 'Intel Corporation' ... I know it is desktop card but i thnik it should not use so much cpu. ...
    (freebsd-net)