Re: [Dle-develop] [PATCH tracing/kprobes 0/7] tracing/kprobes: kprobe-based event tracer update and perf support

[Mark W. <mj...@re...>]

On Fri, 2009-09-11 at 15:06 -0400, Christoph Hellwig wrote:
> On Fri, Sep 11, 2009 at 03:03:35PM -0400, Frank Ch. Eigler wrote:
> > Frederic Weisbecker <fwe...@gm...> writes:
> > 
> > > [...]  I'm really looking forward seeing this C expression-like
> > > kprobe creation tool.  It seems powerful enough to replace printk +
> > > kernel rebuild.  No need anymore to write some printk to debug,
> > > worrying, [...]
> > 
> > To a large extent, systemtap had delivered this already some years
> > ago, including the cushy ponies dancing in the sunlight.  While such
> > low-level machinery is fine, some of our experience indicates that it
> > is dramatically easier to use if high-level, symbolic, debugging data
> > is used to compute probe locations and variable names/types/locations.
> 
> No, systemtap has been for years failing to delivers this in a way that
> it could be usefully integrated into the kernel.

You are saying "No" to a claim Frank didn't even make.

>   Masami's patches are
> exactly the kind of low-level functionality we absolutely need in the
> kernel tree so that we can built more useful higherlevel tools ontop
> of this. 

And nobody is denying that either. I think everybody agrees that Masami
is doing some really wonderful work and improving the kprobes
foundations in a way that any higher level tracing tool will benefit
from it.

Cheers,

Mark