Re: [PATCH 0/3] A kernel tracing interface

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 26 Feb 2008 14:38:37 -0800 "David J. Wilder" <dwilder@us.ibm.com> wrote:

> These patches provide a kernel tracing interface called "trace".
> 
> ChangeLog:
> -Updated to 2.6.25-rc2-mm1
> -Removed sem_watch example, to hard to maintain.
> -Added a new example that demonstrates per-cpu continuous tracing
>  of data generated using marker probes.
> -Removed inline from relay patch.
> -Moved examples into /sample directory.
> 
> The motivation for "trace" is to:
> - Provide a simple set of tracing primitives that will utilize the high-
>   performance and low-overhead of relayfs for passing traces data from
>   kernel to user space.
> - Provide a common user interface for managing kernel traces.
> - Allow for binary as well as ascii trace data.
> - Incorporate features from the systemtap runtime that are
>   useful to others.

So... what's the story on this versus lttng?

Is there some userspace code available for people to test this?  Maybe it's
mentioned and I missed it.

It'd be interesting to see a writeup of the proposed kernel<->userspace
interfaces.  I see a description of kernel-internal interfaces, but how do
users use it?

I see it uses things from blktrace.  Can blktrace be switched over to being
a client of this code?