linux/tools/build/feature/test-get_cpuid.c
Arnaldo Carvalho de Melo b0063dbfb0 tools build: Add test for presence of __get_cpuid() gcc builtin
The auxtrace code needed by Intel PT uses the __get_cpuid() gcc builtin,
that is not present in old systems, breaking the build.

Add a test to check for that builtin and disable AUXTRACE in those
systems.

  [acme@rhel5 linux]$  make NO_LIBPERL=1 -C tools/perf O=/tmp/build/perf install-bin
  make: Entering directory `/home/acme/git/linux/tools/perf'
    BUILD:   Doing 'make -j2' parallel build

  Auto-detecting system features:
  <SNIP>
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ OFF ]
  <SNIP>
  config/Makefile:630: Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc
    MKDIR    /tmp/build/perf/util/
  <SNIP>

This fixes the build on old systems such as RHEL/CentOS 5.11.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Victor Kamensky <victor.kamensky@linaro.org>
Cc: Vinson Lee <vlee@twopensource.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4puslul0jltoodzpx9r4sje@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-17 13:14:35 -03:00

8 lines
140 B
C

#include <cpuid.h>
int main(void)
{
unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
return __get_cpuid(0x15, &eax, &ebx, &ecx, &edx);
}