Re: patches to actually use markers?

[David Smith <dsmith at redhat dot com>]

Mathieu,

Thanks for the pointers, I'll take a look at your patches.

Mathieu Desnoyers wrote:
> * David Smith (dsmith@redhat.com) wrote:
> > Mathieu,
> >
> > Now that the markers facility itself has made it in the kernel, do you 
> > have plans on trying to send patches that actually use markers to lkml?
> >
> > For systemtap's use, we'd like to get some actual markers in the 
> > upstream kernel.  Off the top of my head, we might start with adding 
> > markers to system calls (sys_*) that contain the system call's argument(s).
>
> Hi David,
>
> Yes, we have something similar in LTTng, we instrument many widely used
> system calls to get the detailed arguments.
>
> Do you want to start having a look at my instrumentation patchset ?
> Those are the 
> lttng-instrumentation-*.patch patches available in the following
> tarball:
>
> http://ltt.polymtl.ca/lttng/patch-2.6.23-mm1-lttng-0.10-pre8.tar.bz2
>
> The patches that you may find interesting to comment are :
>
> lttng-kernel-trace-thread-flag-*
>   These patches adds a thread flag for kernel wide syscall trace
>   activation.
>   Note that I would gladly accept some help with the
>     lttng-kernel-trace-thread-flag-ia64.patch
>     lttng-kernel-trace-thread-flag-s390.patch
>     lttng-instrumentation-s390.patch
>   They need to add the 9th bit of thread flag that has to be checked by
>   a 8 bit limited instruction on these architectures.
>
> lttng-instrumentation-*
>   Actual markers. It also includes assembly code change to use the
>   thread flags for syscall_trace.
>   Some architectures do not have complete architecture specific marker
>   set complete.
>
> It's a good thing that we start having a discussion about these marker
> sites at this point.
>
> Mathieu


--
David Smith
dsmith@redhat.com
Red Hat
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