src/devices/timer.c

@@ -208,6 +208,7 @@ timer_interrupt (struct intr_frame *args UNUSED)
       else
         break;
     }
+  thread_increment_recent_cpu ();
   thread_tick ();
 }
 

src/threads/thread.c

@@ -382,6 +382,19 @@ calculate_recent_cpu (void)
   return { 0 };
 }
 
+void
+thread_increment_recent_cpu (void)
+{
+  struct thread *t = thread_current ();
+  if (t == idle_thread)
+  {
+    return;
+  }
+  fp32_t old_recent_cpu = t->recent_cpu;
+  old_recent_cpu.raw = old_recent_cpu.raw + 1;
+  t->recent_cpu = old_recent_cpu;
+}
+
 /* Sets the current thread's nice value to NICE. */
 void
 thread_set_nice (int nice)