Re: [PATCH] perf regs: Add alpha support

[Ian Rogers]

On Mon, Oct 12, 2026 at 2:41 PM Magnus Lindholm <linmag7@xxxxxxxxx> wrote:
>
> Hi again,
>
> On Mon, Oct 12, 2026 at 7:37 PM Magnus Lindholm <linmag7@xxxxxxxxx> wrote:
> > > base-commit: bc01105ed65d15787b2eb93ac26e8624a2139e35
> > > change-id: 20261001-alpha-perf-tools-regs-c206a84dec7f
> > >
> > > Best regards,
> > > --
> > > Matt Turner <mattst88@xxxxxxxxx>
> > >
> >
> > Thanks for doing this!
> >
> > Register selection, recording, decoding and user stack dumps tested
> > on my ES40. End-to-end DWARF unwinding remains unverified because the
> > installed elfutils 0.195 lacks Alpha unwinding support.
> >
> > Tested-by: Magnus Lindholm <linmag7@xxxxxxxxx>
>
> I just pulled your elfutils patches and ran some more tests.
> With your elfutils patches, DWARF unwinding now works on my ES40.
> Both existing and fresh perf recordings recovered the expected
> leaf -> middle -> outer -> main call chain.
>
> As documented, samples whose CFA depends on r15 stopped at the
> sampled frame, since r15 is unavailable. Tested-by tag already given
> to this series.

I'm finding this fantastic and exciting to follow! Being greedy, does
the cross-platform DWARF unwinding work? perf record on an alpha and
perf report on, say, an x86. It would in no way block this work, but
I'm keen to check Matt/I wired this up properly :-)

Thanks,
Ian

> Thanks,
> Magnus