sched_getcpu: input and sample outputs

README.adoc

@@ -17305,6 +17305,30 @@ So when running a multicore program, we may see that each thread can be running
 
 The cores in which the process runs can be fixed with `sched_setaffinity` as shown at: link:userland/linux/sched_getaffinity.c[].
 
+So when I run it with `main` thread + 4 threads on a 4 core CPUs:
+
+....
+./userland/linux/sched_getcpu.out 4
+....
+
+I see random outputs like:
+
+....
+7
+2
+1
+5
+....
+
+and:
+
+....
+5
+0
+2
+1
+....
+
 === Linux calling conventions
 
 A summary of results is shown at: xref:table-linux-calling-conventions[xrefstyle=full].

userland/linux/sched_getcpu.c

@@ -12,7 +12,7 @@
 
 void* main_thread(void *arg) {
     (void)arg;
-    printf("sched_getcpu = %d\n", sched_getcpu());
+    printf("%d\n", sched_getcpu());
     return NULL;
 }