FReebsd 5.0 network performance problem

Sean Chittenden sean at
Thu May 15 15:11:18 PDT 2003

> [..snip..]
> >Don't use 5.0 for production.  If you are going to put anything in
> >production, use a _very_ recent -CURRENT.  Even then, 5.0 isn't as
> >fast as the -STABLE series at the moment because it's still in an
> >awkward transition between locking via giant and fine grain locking.
> >If you'd like to help figure out performance problems for -CURRENT
> >however, have you tried running any kernel profiling to see where the
> >kernel is spending it's cycles?  -sc
> What's the appropraite way to run kernel profiling, and how do you 
> read/pull out the results?

Kernel Profiling in a nut shell:

1) Add "makeoptions DEBUG=-g" and "makeoptions PROFLEVEL=2" to your
   kernel config, recompile your kernel, install, and reboot.  Use
   PROFLEVEL=1 for non-high resolution profiling.
2) Read kgmon(8) and gprof(1)
3) Repeat step #2 as many times as necessary.
4) Post any interesting results to this list with a detailed summary
   of what you were doing, what you think was interesting about the
   results, what version OS, what you'd expect the results to be like,
   and any hunches you may have about the results or why the results
   are what they are.  Any relevant kernel config or sysctl tweaks
   should be included in the report too.
5) Remember at all times to keep in mind that SMPng isn't done and KSE
   isn't finished either and once those two projects are finished, the
   results may look radically different.

Failure to comply with rules 1-5 will result in pointy hats, flamage,
moderation, or filtering.  :) Let's please try and keep this as
objective as possible.


performance@ != chat@ != questions@ != high signal to noise ratio

Sean Chittenden

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