diff --git a/kernel/proc.c b/kernel/proc.c
index 57528f9..e63cc9f 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -49,7 +49,7 @@ mycpu(void) {
   return c;
 }
 
-// Return the current struct proc *.
+// Return the current struct proc *, or zero if none.
 struct proc*
 myproc(void) {
   push_off();
@@ -421,7 +421,7 @@ scheduler(void)
   
   c->proc = 0;
   for(;;){
-    // Let devices interrupt when no lock is held.
+    // Avoid deadlock by ensuring that devices can interrupt.
     intr_on();
 
     for(p = proc; p < &proc[NPROC]; p++) {