Export a list of VM objects in the system via a sysctl. The list can be

examined via 'vmstat -o'.  It can be used to determine which files are
using physical pages of memory and how much each is using.

Differential Revision:	https://reviews.freebsd.org/D2277
Reviewed by:	alc, kib
MFC after:	2 weeks
Sponsored by:	Norse Corp, Inc. (forward porting to HEAD/10)

1 files changed, 94 insertions, 0 deletions

diff --git a/lib/libutil/kinfo_getvmobject.c b/lib/libutil/kinfo_getvmobject.c
new file mode 100644
index 0000000..7e031da
--- /dev/null
+++ b/lib/libutil/kinfo_getvmobject.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2013 Hudson River Trading LLC
+ * Written by: John H. Baldwin <jhb@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <sys/user.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libutil.h"
+
+struct kinfo_vmobject *
+kinfo_getvmobject(int *cntp)
+{
+	char *buf, *bp, *ep;
+	struct kinfo_vmobject *kvo, *list, *kp;
+	size_t len;
+	int cnt, i;
+
+	buf = NULL;
+	for (i = 0; i < 3; i++) {
+		if (sysctlbyname("vm.objects", NULL, &len, NULL, 0) < 0)
+			return (NULL);
+		buf = reallocf(buf, len);
+		if (buf == NULL)
+			return (NULL);
+		if (sysctlbyname("vm.objects", buf, &len, NULL, 0) == 0)
+			goto unpack;
+		if (errno != ENOMEM) {
+			free(buf);
+			return (NULL);
+		}
+	}
+	free(buf);
+	return (NULL);
+
+unpack:
+	/* Count items */
+	cnt = 0;
+	bp = buf;
+	ep = buf + len;
+	while (bp < ep) {
+		kvo = (struct kinfo_vmobject *)(uintptr_t)bp;
+		bp += kvo->kvo_structsize;
+		cnt++;
+	}
+
+	list = calloc(cnt, sizeof(*list));
+	if (list == NULL) {
+		free(buf);
+		return (NULL);
+	}
+
+	/* Unpack */
+	bp = buf;
+	kp = list;
+	while (bp < ep) {
+		kvo = (struct kinfo_vmobject *)(uintptr_t)bp;
+		memcpy(kp, kvo, kvo->kvo_structsize);
+		bp += kvo->kvo_structsize;
+		kp->kvo_structsize = sizeof(*kp);
+		kp++;
+	}
+	free(buf);
+	*cntp = cnt;
+	return (list);
+}