perf test workload thloop: Make count increments atomic

The count variable is incremented by multiple threads, doing so
without an atomic operation causes thread sanitizer warnings. Switch
to using relaxed atomics.

Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

tools/perf/tests/workloads/thloop.c

@@ -20,7 +20,7 @@ static void sighandler(int sig __maybe_unused)
 noinline void test_loop(void)
 {
 	while (!done)
-		count++;
+		__atomic_fetch_add(&count, 1, __ATOMIC_RELAXED);
 }
 
 static void *thfunc(void *arg)