perf top: Error handling for counter creation should parallel perf-re…

…cord

5a7ed29 fixed up perf-record but not perf-top. Similar argument holds
for it -- fallback to PMU only if it does not exist and handle invalid
attributes separately.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Link: http://lkml.kernel.org/r/1343616783-6360-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-top.c

@@ -943,8 +943,10 @@ static void perf_top__start_counters(struct perf_top *top)
 			 * based cpu-clock-tick sw counter, which
 			 * is always available even if no PMU support:
 			 */
-			if (attr->type == PERF_TYPE_HARDWARE &&
-			    attr->config == PERF_COUNT_HW_CPU_CYCLES) {
+			if ((err == ENOENT || err == ENXIO) &&
+			    (attr->type == PERF_TYPE_HARDWARE) &&
+			    (attr->config == PERF_COUNT_HW_CPU_CYCLES)) {
+
 				if (verbose)
 					ui__warning("Cycles event not supported,\n"
 						    "trying to fall back to cpu-clock-ticks\n");