Re: Systemtap on the ARM processor....

[William Cohen <wcohen at redhat dot com>]

On 04/01/2010 04:02 AM, Goeusse, Francois wrote:
> Hi,

Hi Francois,

> 
> Would it be possible to work on getting those patches into the
> upstream SystemTap package? -> Before doing so, it may be recommended
> to explain how these patches were 'found'. Actually, rel 1.0 did not
> seem to properly work for ARM core as is. However, some information
> on the web clearly mentioned that previous systemtap releases could
> be used with ARM cores. Therefore, these patches deal with (or
> cancel) the code updates between 1.0 and older releases which seemed
> to specifically prevent systemtap from properly operating on ARM. 
> Therefore, before submitting any changes into the upstream and
> guarantee the backward compatibility for all platforms, it may be
> preferable to check what motivated these particular code updates? 
> This is question where a longer/better expertise in the tool code may
> be preferable. Any opinion on this?
> 
> Is the kernel/arch/arm/include/asm/ptrace.h patch needed for
> systemtap? -> Might be different for a more recent release of the
> tool, but yes this was needed for rel 1.0 (these lines were part of
> previous releases of the kernel).
> 

I looked through the git repository and found the following patch for systemtap on ARM:

http://sources.redhat.com/git/gitweb.cgi?p=systemtap.git;a=commit;h=958c58e8231563e9349e4d8ea56c04c25e1501c0

It might be better to patch systemtap source rather than the kernel.

> The wiki page mentions a library of scripts at:
> http://omappedia.org/wiki/Systemtap Are any of those general purpose
> that would be useful for other platforms? -> Generic scripts should
> become available progressively (timeframe still under discussion).
> They do not comply with the guidelines yet... but they will have to
> ;-) Then, there should no issue with submitting these scripts to the
> examples directory.

I would be glad to review the scripts and help make them acceptable for inclusion into the examples directory. 

-Will