checkpoint for lock lab

kernel/fs.c

@@ -93,7 +93,7 @@ bfree(int dev, uint b)
 {
   struct buf *bp;
   int bi, m;
-  printf("%d %d\n",dev,b);
+
   bp = bread(dev, BBLOCK(b, sb));
   bi = b % BPB;
   m = 1 << (bi % 8);

user/kalloctest.c

@@ -168,7 +168,7 @@ void test3(void)
   kill(pid);
 
   n = ntas(1);
-  if(n-m < 10000) 
+  if(n-m < 4000) 
     printf("\ntest3 OK\n");
   else
     printf("test3 FAIL m %d n %d\n", m, n);