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charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Nov 10, 2025 at 10:21=E2=80=AFPM Namhyung Kim = wrote: > > Hi Ian, > > On Sun, Nov 09, 2025 at 05:31:47PM -0800, Ian Rogers wrote: > > Switch the __get_cpuid feature for intel-pt to use the provided cpuid > > function in perf, this removes the need for NO_AUXTRACE when the > > feature detection fails. Remove the now unnecessary feature > > detection. Remove NO_AUXTRACE as it just builds a more broken version > > Can you please elaborate what the broken part is? Sure. I'll summarize what alters in patch 4. NO_AUXTRACE is controlling 3 main things: * set up of aux options for PMUs (code in the arch directory) * ARM: coresight and SPE * Intel: BTS and PT * PowerPC: VPA DTL * S390: cpumsf * support for decoding aux events (common code that can be cross-compiled assuming other library dependencies are available) * ARM: coresight * HiSi: PTT decoder * Intel: BTS and PT * PowerPC: VPA DTL * S390: cpumsf * Tool support for aux buffers (common shared builtin code): * perf record: aux options for events, snapshot, aux-sample * perf inject: aux events will fail the entire perf inject command So somebody with a NO_AUXTRACE build would generally experience a very sad perf command. Having the option made sense when there were feature tests that could fail, but possibly that should have just controlled not compiling intel-pt. Having the option is extra burden on developers/maintainers, as shown in my comment: > This was prompted by needing to make a v2 patch set of: > https://lore.kernel.org/lkml/20251107170712.2302714-1-irogers@google.com/ > due to a broken NO_AUXTRACE configuration. Somebody may have been using NO_AUXTRACE as a proxy for not having some library, but I don't see that in the code. If this is the case we should add the appropriate feature test, .. Not having NO_AUXTRACE may have been a bug work around for someone, in which case we should work to fix the bug. Again, I don't know of this case and don't see it in the code. Thanks, Ian > Thanks, > Namhyung