[linuxtools-dev] Oprofile plugin issues with Power processors

[Daniel HB <danielhb@xxxxxxxxxx>]

I'm currently trying to make the Oprofile plugin work on a Power6
machine. I've come to this mailing list a couple weeks ago with a
complaint that generated a bug
( https://bugs.eclipse.org/bugs/show_bug.cgi?id=336977 ) which we
managed to solve - the XML error was a bogus character generated on the
oprofile application for Power.

That wasn't enough to make the plugin work. On some point of its
initialization, the plugin queries 'ophelp <event_name>' searching for
index values to each event detected. It turns out that, on x86, these
events are valid integer values, and the plugin was built around that
assumption. However, on Power, they aren't always a valid integer.
Several 'ophelp <event_name>' calls on Power returns several hex values,
firing an exception on the plugin since an integer value was expected.

Speaking with Maynard Johnson, lead maintainer of Oprofile, we agreed
that the plugin shouldn't be using any value obtained by 'ophelp
<event_name>' since it's a non-architected interface. In other words,
the GUI shouldn't be issuing this command neither using its return
value.

Since it's quite a change on the code (I took a look at where the output
of ophelp is used and there are a lot of places), I think I would need
some help doing that.


Any thoughts/advice?

- daniel