perf stat: Factor out open error handling

Factor out the open error handling into a separate function.  This is
useful for followon patches who need to duplicate this.

No behavior change intended.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191121001522.180827-9-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-stat.c

@@ -420,6 +420,57 @@ static bool is_target_alive(struct target *_target,
 	return false;
 }
 
+enum counter_recovery {
+	COUNTER_SKIP,
+	COUNTER_RETRY,
+	COUNTER_FATAL,
+};
+
+static enum counter_recovery stat_handle_error(struct evsel *counter)
+{
+	char msg[BUFSIZ];
+	/*
+	 * PPC returns ENXIO for HW counters until 2.6.37
+	 * (behavior changed with commit b0a873e).
+	 */
+	if (errno == EINVAL || errno == ENOSYS ||
+	    errno == ENOENT || errno == EOPNOTSUPP ||
+	    errno == ENXIO) {
+		if (verbose > 0)
+			ui__warning("%s event is not supported by the kernel.\n",
+				    perf_evsel__name(counter));
+		counter->supported = false;
+
+		if ((counter->leader != counter) ||
+		    !(counter->leader->core.nr_members > 1))
+			return COUNTER_SKIP;
+	} else if (perf_evsel__fallback(counter, errno, msg, sizeof(msg))) {
+		if (verbose > 0)
+			ui__warning("%s\n", msg);
+		return COUNTER_RETRY;
+	} else if (target__has_per_thread(&target) &&
+		   evsel_list->core.threads &&
+		   evsel_list->core.threads->err_thread != -1) {
+		/*
+		 * For global --per-thread case, skip current
+		 * error thread.
+		 */
+		if (!thread_map__remove(evsel_list->core.threads,
+					evsel_list->core.threads->err_thread)) {
+			evsel_list->core.threads->err_thread = -1;
+			return COUNTER_RETRY;
+		}
+	}
+
+	perf_evsel__open_strerror(counter, &target,
+				  errno, msg, sizeof(msg));
+	ui__error("%s\n", msg);
+
+	if (child_pid != -1)
+		kill(child_pid, SIGTERM);
+	return COUNTER_FATAL;
+}
+
 static int __run_perf_stat(int argc, const char **argv, int run_idx)
 {
 	int interval = stat_config.interval;
@@ -469,48 +520,17 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 				goto try_again;
 			}
 
-			/*
-			 * PPC returns ENXIO for HW counters until 2.6.37
-			 * (behavior changed with commit b0a873e).
-			 */
-			if (errno == EINVAL || errno == ENOSYS ||
-			    errno == ENOENT || errno == EOPNOTSUPP ||
-			    errno == ENXIO) {
-				if (verbose > 0)
-					ui__warning("%s event is not supported by the kernel.\n",
-						    perf_evsel__name(counter));
-				counter->supported = false;
-
-				if ((counter->leader != counter) ||
-				    !(counter->leader->core.nr_members > 1))
-					continue;
-			} else if (perf_evsel__fallback(counter, errno, msg, sizeof(msg))) {
-                                if (verbose > 0)
-                                        ui__warning("%s\n", msg);
-                                goto try_again;
-			} else if (target__has_per_thread(&target) &&
-				   evsel_list->core.threads &&
-				   evsel_list->core.threads->err_thread != -1) {
-				/*
-				 * For global --per-thread case, skip current
-				 * error thread.
-				 */
-				if (!thread_map__remove(evsel_list->core.threads,
-							evsel_list->core.threads->err_thread)) {
-					evsel_list->core.threads->err_thread = -1;
+			switch (stat_handle_error(counter)) {
+			case COUNTER_FATAL:
+				return -1;
+			case COUNTER_RETRY:
 				goto try_again;
+			case COUNTER_SKIP:
+				continue;
+			default:
+				break;
 			}
 		}
-
-			perf_evsel__open_strerror(counter, &target,
-						  errno, msg, sizeof(msg));
-			ui__error("%s\n", msg);
-
-			if (child_pid != -1)
-				kill(child_pid, SIGTERM);
-
-			return -1;
-		}
 		counter->supported = true;
 
 		l = strlen(counter->unit);