$OpenBSD: patch-sysdeps_openbsd_open_c,v 1.6 2014/07/11 16:57:55 robert Exp $
--- sysdeps/openbsd/open.c.orig	Mon Apr 28 23:09:24 2014
+++ sysdeps/openbsd/open.c	Fri Jul 11 18:56:55 2014
@@ -23,6 +23,8 @@
 #include <sys/types.h>
 #include <glibtop.h>
 #include <glibtop/open.h>
+#include <glibtop/cpu.h>
+#include <glibtop/error.h>
 
 #include <glibtop_private.h>
 
@@ -32,5 +34,24 @@ glibtop_open_s (glibtop *server, const char *program_n
 		const unsigned long features,
 		const unsigned flags)
 {
+	int ncpus = 1;
+	int mib[2] = { CTL_HW, HW_NCPU };
+	size_t len;
+
+	len = sizeof(ncpus);
+	if (sysctl(mib, 2, &ncpus, &len, NULL, 0) != 0)
+		printf("Couldn't determine hw.ncpu.\n");
+
+	server->real_ncpu = ncpus - 1;
+	server->ncpu = MIN(GLIBTOP_NCPU - 1, server->real_ncpu);
+
 	server->os_version_code = OpenBSD;
+
+	if (server->real_ncpu != server->ncpu) {
+		glibtop_warn_r(server,
+			"This machine has %d CPUs, "
+			"%d are being monitored.",
+			server->real_ncpu + 1,
+			server->ncpu + 1);
+	}
 }
