Re: [PATCH v3 0/9] perf: Default use of build IDs and improvements

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Tue, May 27, 2025 at 01:48:43PM -0700, Ian Rogers wrote:
> On Mon, Apr 28, 2025 at 2:34 PM Ian Rogers <irogers@google.com> wrote:
> >
> > Build ID mmap2 events have been available since Linux v5.12 and avoid
> > certain races. Enable these by default as discussed in:
> > https://lore.kernel.org/linux-perf-users/CAP-5=fXP7jN_QrGUcd55_QH5J-Y-FCaJ6=NaHVtyx0oyNh8_-Q@mail.gmail.com/
> >
> > The dso_id is used to indentify a DSO that may change by being
> > overwritten. The inode generation isn't present in /proc/pid/maps and
> > so was already only optionally filled in. With build ID mmap events
> > the other major, minor and inode varialbes aren't filled in. Change
> > the dso_id implementation to make optional values explicit, rather
> > than injecting a dso_id we want to improve it during find operations,
> > add the buildid to the dso_id for sorting and so that matching fails
> > when build IDs vary between DSOs.
> >
> > Mark the callchain for buildids and not just the sample IP, fixing
> > missing DSOs.
> >
> > Fix sample__for_each_callchain_node to populate the map even when
> > symbols aren't computed.
> >
> > Other minor bits of build_id clean up.
> >
> > v3: Ensure the struct build_id is initialized empty prior to use as
> >     read paths may fail (Namhyung).
> >
> > v2: Make marking DSOs still the default even with the defaulted build
> >     ID mmap. The command line option still disables this to avoid
> >     regressions. Add callchain patches and jitdump fix.
> 
> Ping. Thanks,
> Ian

⬢ [acme@toolbx perf-tools-next]$        git am ./v3_20250428_irogers_perf_default_use_of_build_ids_and_improvements.mbx
Applying: perf callchain: Always populate the addr_location map when adding IP
Applying: perf build-id: Reduce size of "size" variable
Applying: perf build-id: Truncate to avoid overflowing the build_id data
Applying: perf build-id: Change sprintf functions to snprintf
Applying: perf build-id: Mark DSO in sample callchains
Applying: perf build-id: Ensure struct build_id is empty before use
Applying: perf dso: Move build_id to dso_id
Applying: perf jitdump: Directly mark the jitdump DSO
Applying: perf record: Make --buildid-mmap the default
error: patch failed: tools/perf/builtin-record.c:3349
error: tools/perf/builtin-record.c: patch does not apply
Patch failed at 0009 perf record: Make --buildid-mmap the default
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
⬢ [acme@toolbx perf-tools-next]$

- Arnaldo