Patch #1005568: Use _SC_PAGESIZE on Irix.
Backported to 2.3.
diff --git a/Modules/resource.c b/Modules/resource.c
index c1b6377..c5bec79 100644
--- a/Modules/resource.c
+++ b/Modules/resource.c
@@ -202,7 +202,12 @@
 #if defined(HAVE_GETPAGESIZE)
 	pagesize = getpagesize();
 #elif defined(HAVE_SYSCONF)
+#if defined(_SC_PAGE_SIZE)
 	pagesize = sysconf(_SC_PAGE_SIZE);
+#else
+	/* Irix 5.3 has _SC_PAGESIZE, but not _SC_PAGE_SIZE */
+	pagesize = sysconf(_SC_PAGESIZE);
+#endif
 #endif
 	return Py_BuildValue("i", pagesize);