INN with hyperthreading/SMP

Bill Davidsen davidsen at
Tue May 11 18:29:11 UTC 2004

Mike Zanker wrote:
> Hi,
> are there any known problems with running INN (2.4.1) on a box with a 
> hyperthreading CPU and SMP linux kernel?

No, it works the nuts. I have been meaning to pthread the incoming 
feeds, but frankly on a moderately fast machine I don't feel that I need 
it, and the reaction to my last question about pthreads in this M/L was 
little to no interest. It does help if you are running overchan and 
innfeed as separate processes.

I would expect the new "E" processors with 1MB cache to do better with 
HT, but until I find a system board to support it with the features and 
price I want, I won't be able to test. I did get one of the CPUs at deep 
discount, but I haven't been able to try it.
> I've built a box to replace my aging feeder with a P4 HT processor and 
> have installed Red Hat Enterprise Linux 3. The SMP kernel was installed 
> by default (2.4.21 with RH mods). I built INN with perl and largefiles 
> so that I could have CNFS buffers >2GB.
> The new box is currently receiving a feed from the feeder but innd is 
> growing at an alarming rate. After a few hours it was using about 350MB 
> RAM. On my reader box (same OS but single P3 processor) with the same 
> feed, innd never gets above about 50MB. Both boxes have 512MB RAM.

You may have some memory issues on a box that small, although I would 
expect the VM to be able to cope with it, at the cost of some performance.
> I've rebooted with a non-SMP kernel to see if it makes any difference 
> but wondered whether this was a known issue.

040     9   751     1  15   0 804912 41464 schedu S  ?        3851:51 
/usr/local/news/bin/innd -p 3 PATH=/usr/local/news/bin:/usr/lo

    -bill davidsen (davidsen at
"The secret to procrastination is to put things off until the
  last possible moment - but no longer"  -me

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