perf data: Add doc when no conversion support compiled
This adds documentation on the environment variables needed to the
message telling that no conversion support is compiled in.
Committer testing:
$ make -C tools/perf install
$ perf data convert --all --to-ctf myctftrace
No conversion support compiled in. perf should be compiled with environment variables LIBBABELTRACE=1 and LIBBABELTRACE_DIR=/path/to/libbabeltrace/
$
Signed-off-by: Geneviève Bastien <gbastien@versatic.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Julien Desfossez <jdesfossez@efficios.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170727181205.24843-3-gbastien@versatic.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-data.c b/tools/perf/builtin-data.c
index 0adb5f8..46cd849 100644
--- a/tools/perf/builtin-data.c
+++ b/tools/perf/builtin-data.c
@@ -69,7 +69,7 @@ static int cmd_data_convert(int argc, const char **argv)
};
#ifndef HAVE_LIBBABELTRACE_SUPPORT
- pr_err("No conversion support compiled in.\n");
+ pr_err("No conversion support compiled in. perf should be compiled with environment variables LIBBABELTRACE=1 and LIBBABELTRACE_DIR=/path/to/libbabeltrace/\n");
return -1;
#endif