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

[ Upstream commit 61a461fcbd62d42c29a1ea6a9cc3838ad9f49401 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 72df4b6fa36fd12ad45cf00cdb0750d27c5d5061..4c45cdf38adae18e7c756bec8a4e543bc5554c13 100644 (file)
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -440,6 +440,9 @@ 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;