perf config: Honour $PERF_CONFIG env var to specify alternate .perfconfig

We had this comment in Documentation/perf_counter/config.c, i.e. since
when we got this from the git sources, but never really did that
getenv("PERF_CONFIG"), do it now as I need to disable whatever
~/.perfconfig root has so that tests parsing tool output are done for
the expected default output or that we specify an alternate config file
that when read will make the tools produce expected output.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Fixes: 078006012401 ("perf_counter tools: add in basic glue from Git")
Link: https://lkml.kernel.org/n/tip-jo209zac9rut0dz1rqvbdlgm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 97e2628ea5dd1532ad0c1c584c53002688a06856..d4e4d53e8b44bb0a08fd7cb8e679e8d260b2c472 100644 (file)
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -441,6 +441,9 @@ int main(int argc, const char **argv)
 
        srandom(time(NULL));
 
+       /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
+       config_exclusive_filename = getenv("PERF_CONFIG");
+
        err = perf_config(perf_default_config, NULL);
        if (err)
                return err;