Merge branch 'master' of g.csail.mit.edu:xv6-dev

exec.c

@@ -20,7 +20,6 @@ exec(char *path, char **argv)
 
   begin_op();
 
-  cprintf("exec %s\n", path);
   if((ip = namei(path)) == 0){
     end_op();
     return -1;
@@ -100,7 +99,6 @@ exec(char *path, char **argv)
   proc->tf->esp = sp;
   switchuvm(proc);
   freevm(oldpgdir);
-  cprintf("exec succeeded\n");
   return 0;
 
  bad:

runoff.list

@@ -35,12 +35,14 @@ sysproc.c
 
 # file system
 buf.h
+sleeplock.h
 fcntl.h
 stat.h
 fs.h
 file.h
 ide.c
 bio.c
+sleeplock.c
 log.c
 fs.c
 file.c

spinlock.c

@@ -61,7 +61,7 @@ release(struct spinlock *lk)
 
   // Release the lock, equivalent to lk->locked = 0.
   // This code can't use a C assignment, since it might
-  // not be atomic.
+  // not be atomic. A real OS would use C atomics here.
   asm volatile("movl $0, %0" : "+m" (lk->locked) : );
 
   popcli();