Improve comment on sema_down.

Thanks to Haobo Xu for pointing this out.

diff --git a/src/threads/synch.c b/src/threads/synch.c
index c2764bc38d1cdb3b47efb0f0a43f8d694d493947..317c68ad501301538f47a697df7a8eaf02d4e077 100644 (file)
--- a/src/threads/synch.c
+++ b/src/threads/synch.c
@@ -55,8 +55,8 @@ sema_init (struct semaphore *sema, unsigned value)
 
    This function may sleep, so it must not be called within an
    interrupt handler.  This function may be called with
-   interrupts disabled, but interrupts will be turned back on if
-   we need to sleep. */
+   interrupts disabled, but if it sleeps then the next scheduled
+   thread will probably turn interrupts back on. */
 void
 sema_down (struct semaphore *sema) 
 {