Re: [PATCH v1 0/2] perf build: Remove libunwind support

Arnaldo Carvalho de Melo
2026-03-30T18:49:12Z

On Fri, Mar 27, 2026 at 06:08:27PM -0300, Arnaldo Carvalho de Melo wrote:
> On Fri, Mar 27, 2026 at 01:37:20PM -0700, Ian Rogers wrote:
> > On Fri, Mar 27, 2026 at 1:07 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> > > This is an area that is tricky and since we _already_ have two
> > > implementations, the good thing for regression testing would be the
> > > compare their results until libunwind becomes completely rotten and
> > > unusable?
> >
> > My series:
> > https://lore.kernel.org/lkml/20260305221927.3237145-1-irogers@google.com/
> > makes libdw and libunwind supported together:
> > https://lore.kernel.org/lkml/20260305221927.3237145-2-irogers@google.com/
> > """
> > This commit refactors the DWARF unwind post-processing to be
> > configurable at runtime via the .perfconfig file option
> > 'unwind.style', or using the argument '--unwind-style' in the commands
> > 'perf report', 'perf script' and 'perf inject', in a similar manner to
> > the addr2line or the disassembler style.
> > """
> > That series cleans up several other issues, which is why I think it is
> > worth landing while we wait for libdw to become stable.
>
> Cool, I'll try and review/test it this weekend.
>
> Thanks for pointint it out!

Pointing, looking at it now, one comment so far, remove that new blank
line, testing...

⬢ [acme@toolbx perf-tools-next]$ git am ./v2_20260305_irogers_perf_libunwind_multiple_remote_support.mbx
Applying: perf unwind: Refactor get_entries to allow dynamic libdw/libunwind selection
.git/rebase-apply/patch:128: new blank line at EOF.
+
warning: 1 line adds whitespace errors.
Applying: perf build loongarch: Remove reference to missing file
Applying: tools build: Deduplicate test-libunwind for different architectures
Applying: perf build: Be more programmatic when setting up libunwind variables
Applying: perf unwind-libunwind: Make libunwind register reading cross platform
Applying: perf unwind-libunwind: Move flush/finish access out of local
Applying: perf unwind-libunwind: Remove libunwind-local
Applying: perf unwind-libunwind: Add RISC-V libunwind support
⬢ [acme@toolbx perf-tools-next]$