kgmon on multiprocessors

[Doug Rabson]

On Wednesday 11 July 2007, Robert Watson wrote:
> On Mon, 2 Jul 2007, Girish Motwani wrote:
> >            Does the kernel profiling tool kgmon give accurate
> > information on multiprocessor systems ?  Or is there some other
> > tool for SMP systems ? I tried looking up the archives for
> > information on this, but could not find any.
>
> Girish--
>
> Take a look at hwpmc(4), pmccontrol(8), and pmcstat(8).  These allow
> you to do kernel-only or systemic samplic using performance
> monitoring counters, including looking at CPU time, cache misses,
> instructions retired, etc.  I posted a sixty second howto here:
>
>   
> http://lists.freebsd.org/pipermail/freebsd-current/2006-February/0610
>96.html
>
> Among other things, you can generate gprof output from PMC; right
> now, that's without full stack traces (and hence callgraphs), but
> Joseph Koshy has work in P4 implementing stack trace support.  I
> imagine this will go in after the 7.0 freeze lets up.

That reminds me - does anyone know what I have to hack to make hwpmc 
work on my Intel(R) Core(TM)2 Quad CPU (Id = 0x6f7, Stepping = 7)?