Re: [PATCH] LTT for 2.5.38 1/9: Core infrastructure

[Andi Kleen <ak@suse.de>]

Linus Torvalds <torvalds@transmeta.com> writes:
> 
> I suspect we'll want to have some form of event tracing eventually, but
> I'm personally pretty convinced that it needs to be a per-CPU thing, and 
> the core mechanism would need to be very lightweight. It's easier to build 
> up complexity on top of a lightweight interface than it is to make a 
> lightweight interface out of a heavy one.

There is an old patch around from SGI that does exactly this. It is a
very lightweight binary value tracer that has per CPU buffers. It
traces using macros that you can easily add. It's called ktrace (not
to be confused with Ingo's ktrace). I've been porting it for some time
for my own tracing needs (adding tracing macros as needed but never submitting
them). If you're interested I can submit it for 2.5 (without any hooks, people
should just add them as needed and then remove them again) 

-Andi