perf tools: Add fallback for exclude_guest

Commit 7b10098 ("perf evlist: Remove __evlist__add_default")
changed to parse "cycles:P" event instead of creating a new cycles
event for perf record.  But it also changed the way how modifiers are
handled so it doesn't set the exclude_guest bit by default.

It seems Apple M1 PMU requires exclude_guest set and returns EOPNOTSUPP
if not.  Let's add a fallback so that it can work with default events.

Also update perf stat hybrid tests to handle possible u or H modifiers.

Reviewed-by: Ian Rogers <[email protected]>
Reviewed-by: James Clark <[email protected]>
Reviewed-by: Ravi Bangoria <[email protected]>
Acked-by: Kan Liang <[email protected]>
Cc: James Clark <[email protected]>
Cc: Atish Patra <[email protected]>
Cc: Mingwei Zhang <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Fixes: 7b10098 ("perf evlist: Remove __evlist__add_default")
Signed-off-by: Namhyung Kim <[email protected]>

Author: namhyung

tools/perf/builtin-stat.c

@@ -640,8 +640,7 @@ static enum counter_recovery stat_handle_error(struct evsel *counter)
 	 * (behavior changed with commit b0a873e).
 	 */
 	if (errno == EINVAL || errno == ENOSYS ||
-	    errno == ENOENT || errno == EOPNOTSUPP ||
-	    errno == ENXIO) {
+	    errno == ENOENT || errno == ENXIO) {
 		if (verbose > 0)
 			ui__warning("%s event is not supported by the kernel.\n",
 				    evsel__name(counter));
@@ -659,7 +658,7 @@ static enum counter_recovery stat_handle_error(struct evsel *counter)
 		if (verbose > 0)
 			ui__warning("%s\n", msg);
 		return COUNTER_RETRY;
-	} else if (target__has_per_thread(&target) &&
+	} else if (target__has_per_thread(&target) && errno != EOPNOTSUPP &&
 		   evsel_list->core.threads &&
 		   evsel_list->core.threads->err_thread != -1) {
 		/*
@@ -680,6 +679,19 @@ static enum counter_recovery stat_handle_error(struct evsel *counter)
 		return COUNTER_SKIP;
 	}
 
+	if (errno == EOPNOTSUPP) {
+		if (verbose > 0) {
+			ui__warning("%s event is not supported by the kernel.\n",
+				    evsel__name(counter));
+		}
+		counter->supported = false;
+		counter->errored = true;
+
+		if ((evsel__leader(counter) != counter) ||
+		    !(counter->core.leader->nr_members > 1))
+			return COUNTER_SKIP;
+	}
+
 	evsel__open_strerror(counter, &target, errno, msg, sizeof(msg));
 	ui__error("%s\n", msg);
 

tools/perf/tests/shell/stat.sh

@@ -185,7 +185,7 @@ test_hybrid() {
   fi
 
   # Run default Perf stat
-  cycles_events=$(perf stat -- true 2>&1 | grep -E "/cycles/|  cycles  " | wc -l)
+  cycles_events=$(perf stat -- true 2>&1 | grep -E "/cycles/[uH]*|  cycles[:uH]*  " -c)
 
   if [ "$pmus" -ne "$cycles_events" ]
   then

tools/perf/util/evsel.c

@@ -3156,6 +3156,27 @@ bool evsel__fallback(struct evsel *evsel, struct target *target, int err,
 		evsel->core.attr.exclude_kernel = 1;
 		evsel->core.attr.exclude_hv     = 1;
 
+		return true;
+	} else if (err == EOPNOTSUPP && !evsel->core.attr.exclude_guest &&
+		   !evsel->exclude_GH) {
+		const char *name = evsel__name(evsel);
+		char *new_name;
+		const char *sep = ":";
+
+		/* Is there already the separator in the name. */
+		if (strchr(name, '/') ||
+		    (strchr(name, ':') && !evsel->is_libpfm_event))
+			sep = "";
+
+		if (asprintf(&new_name, "%s%sH", name, sep) < 0)
+			return false;
+
+		free(evsel->name);
+		evsel->name = new_name;
+		/* Apple M1 requires exclude_guest */
+		scnprintf(msg, msgsize, "trying to fall back to excluding guest samples");
+		evsel->core.attr.exclude_guest = 1;
+
 		return true;
 	}