Re: [PATCH 2/2] perf annotate: add powerpc support

From: Naveen N. Rao
Date: Fri Jun 10 2016 - 12:03:09 EST


On 2016/06/10 08:08PM, Naveen N. Rao wrote:
> On 2016/06/10 10:36AM, Arnaldo Carvalho de Melo wrote:
> > Em Fri, Jun 10, 2016 at 06:32:51PM +0530, Naveen N. Rao escreveu:
> > > Convert ins__find() to a __weak function for generic functionality,
> > > while adding a powerpc-specific variant. We look at the function name
> > > for branch instructions and classify the instructions to one among a
> > > branch, a function call (branch with LR update) or a function return
> > > (branch to LR).
> >
> > How would this allow one to get a perf.data collected on a powerpc
> > system, transfer it to a x86-64 (or aarch64, to mention another
> > workstation wannabe chip) system and then try annotating it?
> >
> > There was a previous discussion about this, and it involved having all
> > yout ppc tables available as well as other arches tables, and then
> > choosing which one to use based on:
> >
> > normalize_arch(thread->mg->machine->env->arch)
> >
> > just like was done for support cross unwinding, see recent patch kit by
> > He Kuang, CCed.
>
> Nice. This would be good to have. I will look at adding powerpc support
> for cross-architecture unwind.
>
> However, for cross-architecture annotation, I think there will be a lot
> more dependencies since perf currently uses objdump to obtain the
> disassembly. In addition, the actual binaries will also be needed.

perf report already has a --objdump flag... will look into this later
next week.

- Naveen