Re: mutexes, locks and so on...

[Simon Burge <simonb%NetBSD.org@localhost>]

Johnny Billquist wrote:

> On 2010-11-20 03:59, Simon Burge wrote:
> > Johnny Billquist wrote:
> >
> >> What I don't get is why it take so much time to even respond to
> >> pings, compared to Ultrix or VMS. What are we doing in the kernel??? As
> >> usual, I'm open to suggestions...
> >
> > Have you tried a profiling kernel?  I know that can introduce its own 
> > overheads,
> > but might point out some hot spots...
> 
> No, I haven't. But it's a good idea. Last time I tried that was many, 
> many moons ago, and back then I never got it to work.

It's been a few moons here too, but used to work well on i386, amd64, mips
and powerpc.

> Do we have some quick intro on how to do it?

This should be enough to get started:

        config -p ...
        build/boot new kernel
        kgmon -br ; sleep XX ; kgmon -ph
          - or -
        kgmon -br ; do-something ; kgmon -ph
        gprof /netbsd

Cheers,
Simon.