From: Godmar Back <godmar@gmail.com>
Date: Fri, 10 Nov 2006 02:20:08 +0000 (+0000)
Subject: make loop counter volatile to prevent gcc4.1 from optimizing away entire loop body
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=commitdiff_plain;h=db7d1db11685c1dc0d97c41049d26b876211551b

make loop counter volatile to prevent gcc4.1 from optimizing away entire loop body
---

diff --git a/src/devices/timer.c b/src/devices/timer.c
index c8c41d5..070c487 100644
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -162,7 +162,7 @@ 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;