Re: [PATCH 2/4] tracing: add event trace infrastructure

[Ingo Molnar]

* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> But we don't do that, because userspace is hard, because we 
> don't have a delivery process.  But nobody has even tried! 
> [...]

Actually, you can do it right now, with the current model:

  echo raw > /debug/tracing/trace_options
  echo bin > /debug/tracing/trace_options

Reality is that rarely does anyone use it because obviously 
self-sufficient kernel instrumentation is very convenient to 
kernel developers, to testers and to bugreporters alike. 
(Processing kernel details in user-space is also often slower 
and duplicates code that the kernel already has like symbol 
lookups.)

_Maybe_ some of it (but certainly not all) could be done via 
klibc - but that got nacked. If you can convince Linus to take 
klibc and to allow a userspace 'halo' of utilities that are 
intimate with kernel details into the kernel proper then maybe 
we could start providing such tools in the kernel proper.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/