Re: [PATCH] perf buildid-list: Fix empty output for AUX data

[Arnaldo Carvalho de Melo]

On Tue, Sep 22, 2026 at 10:21:25PM -0700, Ian Rogers wrote:
> On Tue, Sep 22, 2026 at 7:47 AM James Clark <james.clark@xxxxxxxxxx> wrote:
> >
> > perf record enables buildid_all for AUX trace because buildid-list does
> > not decode AUX data to identify hit DSOs. Historically those build IDs
> > were available in HEADER_BUILD_ID, and buildid-list disabled hit
> > filtering when HEADER_AUXTRACE was present.
> >
> > Build IDs are now carried by MMAP2 records by default and the build-ID
> > header is omitted. perf_session__list_build_ids() forces with_hits when
> > the header is absent so that it processes the event stream. That also
> > filters the result to DSOs referenced by ordinary samples. AUX data has
> > no such samples unless the trace is decoded, so every DSO is dropped and
> > perf archive reports that no build IDs were found.
> >
> > Process the event stream whenever the build-ID header is absent,
> > allowing MMAP2 build IDs to be read, but do not enable hit filtering for
> > AUX data, this ensures that all build-IDs are included for AUX data.
> >
> > Fixes: 6bd89ae7d147 ("perf record: Make sure to update build-ID cache")
> > Assisted-by: Codex:GPT-5.6-Sol
> > Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
> 
> Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks, applied to perf-tools-next, for v7.4.

- Arnaldo