Re: [PATCH v11 1/4] perf check: introduce check subcommand

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

On Fri, Jun 28, 2024 at 11:28:14AM -0700, Namhyung Kim wrote:
> On Fri, Jun 28, 2024 at 11:24:53AM -0300, Arnaldo Carvalho de Melo wrote:
> 
> > And while looking at it:
> > 
> >              get_cpuid: [ on  ]  # HAVE_AUXTRACE_SUPPORT
> > 
> > This looks wrong, no? Or at least confusing, have to check the source
> > code...
> 
> We have this in Makefile.config
> 
> ifndef NO_AUXTRACE
>   ifeq ($(SRCARCH),x86)
>     ifeq ($(feature-get_cpuid), 0)
>       $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc)
>       NO_AUXTRACE := 1
>     endif
>   endif

The complete sequence is:

ifndef NO_AUXTRACE
  ifeq ($(SRCARCH),x86)
    ifeq ($(feature-get_cpuid), 0)
      $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc)
      NO_AUXTRACE := 1
    endif
  endif
  ifndef NO_AUXTRACE
    $(call detected,CONFIG_AUXTRACE)
    CFLAGS += -DHAVE_AUXTRACE_SUPPORT
    ifeq ($(feature-reallocarray), 0)
      CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
    endif
  endif
endif

The most descriptive would be to HAVE_GET_CPUID_SUPPORT and have it used
in the source code.

That or have:

diff --git a/tools/perf/builtin-check.c b/tools/perf/builtin-check.c
index 44ffde6f8dbe51f3..ae4a686ff4f265be 100644
--- a/tools/perf/builtin-check.c
+++ b/tools/perf/builtin-check.c
@@ -33,7 +33,7 @@ struct feature_status supported_features[] = {
 	FEATURE_STATUS("dwarf", HAVE_DWARF_SUPPORT),
 	FEATURE_STATUS("dwarf_getlocations", HAVE_DWARF_GETLOCATIONS_SUPPORT),
 	FEATURE_STATUS("dwarf-unwind-support", HAVE_DWARF_UNWIND_SUPPORT),
-	FEATURE_STATUS("get_cpuid", HAVE_AUXTRACE_SUPPORT),
+	FEATURE_STATUS("auxtrace", HAVE_AUXTRACE_SUPPORT),
 	FEATURE_STATUS("libaudit", HAVE_LIBAUDIT_SUPPORT),
 	FEATURE_STATUS("libbfd", HAVE_LIBBFD_SUPPORT),
 	FEATURE_STATUS("libcapstone", HAVE_LIBCAPSTONE_SUPPORT),

That:

        FEATURE_STATUS("dwarf-unwind-support", HAVE_DWARF_UNWIND_SUPPORT),

Should also really be:

        FEATURE_STATUS("dwarf-unwind", HAVE_DWARF_UNWIND_SUPPORT),

For consistency, the get_cpuid/auxtrace also for consistency, I think.

- Arnaldo