X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=blobdiff_plain;f=src%2Fuserprog%2Fexception.c;h=8b2e8b641adf7b90168b7b3ff4b3ae81e2bf4d6c;hp=f31f7a884a323b12b48c6c598d1fa6689fc57fa3;hb=838c30d0075a3ee0413ba4909944b37f4970a10d;hpb=cc409b1863cc91b6a2dbfc963d221ab548132762

diff --git a/src/userprog/exception.c b/src/userprog/exception.c
index f31f7a8..8b2e8b6 100644
--- a/src/userprog/exception.c
+++ b/src/userprog/exception.c
@@ -5,6 +5,9 @@
 #include "threads/interrupt.h"
 #include "threads/thread.h"
 
+/* Number of page faults processed. */
+static long long page_fault_cnt;
+
 static void kill (struct intr_frame *);
 static void page_fault (struct intr_frame *);
 
@@ -54,6 +57,13 @@ exception_init (void)
   intr_register (14, 0, INTR_OFF, page_fault, "#PF Page-Fault Exception");
 }
 
+/* Prints exception statistics. */
+void
+exception_print_stats (void) 
+{
+  printf ("Exception: %lld page faults\n", page_fault_cnt);
+}
+
 /* Handler for an exception (probably) caused by a user process. */
 static void
 kill (struct intr_frame *f) 
@@ -129,6 +139,9 @@ page_fault (struct intr_frame *f)
      be assured of reading CR2 before it changed). */
   intr_enable ();
 
+  /* Count page faults. */
+  page_fault_cnt++;
+
   /* Determine cause. */
   not_present = (f->error_code & PF_P) == 0;
   write = (f->error_code & PF_W) != 0;