X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdevices%2Ftimer.c;h=662e0c6f5645be139fde64f9f300bcd0f17d9c52;hb=48fe0532fd45f71d867b1550190689ab1196def4;hp=c8c41d55cf412948eb71a04b52c748f0c554465d;hpb=400c8c5ba0d309716ad7d347dff067ddb2f99a74;p=pintos-anon

diff --git a/src/devices/timer.c b/src/devices/timer.c
index c8c41d5..662e0c6 100644
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -57,8 +57,11 @@ timer_calibrate (void)
   /* Approximate loops_per_tick as the largest power-of-two
      still less than one timer tick. */
   loops_per_tick = 1u << 10;
-  while (!too_many_loops (loops_per_tick << 1))
-    loops_per_tick <<= 1;
+  while (!too_many_loops (loops_per_tick << 1)) 
+    {
+      loops_per_tick <<= 1;
+      ASSERT (loops_per_tick != 0);
+    }
 
   /* Refine the next 8 bits of loops_per_tick. */
   high_bit = loops_per_tick;
@@ -162,7 +165,7 @@ too_many_loops (unsigned loops)
    differently in different places the results would be difficult
    to predict. */
 static void NO_INLINE
-busy_wait (int64_t loops) 
+busy_wait (volatile int64_t loops) 
 {
   while (loops-- > 0)
     continue;