1/*-
2 * Copyright (c) 2008 Yahoo!, Inc.
3 * All rights reserved.
4 * Written by: John Baldwin <jhb@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the author nor the names of any co-contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD$");
33
34#include <sys/param.h>
35#include <sys/pcpu.h>
36#include <sys/resource.h>
37#include <sys/sysctl.h>
38#include <errno.h>
39#include <kvm.h>
40#include <limits.h>
41#include <stdlib.h>
42#include <string.h>
43
44#include "kvm_private.h"
45
46static struct nlist kvm_cp_time_nl[] = {
47	{ .n_name = "_cp_time" },		/* (deprecated) */
48	{ .n_name = NULL },
49};
50
51#define	NL_CP_TIME		0
52
53static int kvm_cp_time_cached;
54
55static int
56_kvm_cp_time_init(kvm_t *kd)
57{
58
59	if (kvm_nlist(kd, kvm_cp_time_nl) < 0)
60		return (-1);
61	kvm_cp_time_cached = 1;
62	return (0);
63}
64
65static int
66getsysctl(kvm_t *kd, const char *name, void *buf, size_t len)
67{
68	size_t nlen;
69
70	nlen = len;
71	if (sysctlbyname(name, buf, &nlen, NULL, 0) < 0) {
72		_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
73		    strerror(errno));
74		return (-1);
75	}
76	if (nlen != len) {
77		_kvm_err(kd, kd->program, "sysctl %s has unexpected size",
78		    name);
79		return (-1);
80	}
81	return (0);
82}
83
84int
85kvm_getcptime(kvm_t *kd, long *cp_time)
86{
87	struct pcpu *pc;
88	int i, j, maxcpu;
89
90	if (kd == NULL) {
91		kvm_cp_time_cached = 0;
92		return (0);
93	}
94
95	if (ISALIVE(kd))
96		return (getsysctl(kd, "kern.cp_time", cp_time, sizeof(long) *
97		    CPUSTATES));
98
99	if (kvm_cp_time_cached == 0) {
100		if (_kvm_cp_time_init(kd) < 0)
101			return (-1);
102	}
103
104	/* If this kernel has a "cp_time[]" symbol, then just read that. */
105	if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
106		if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
107		    sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
108			_kvm_err(kd, kd->program, "cannot read cp_time array");
109			return (-1);
110		}
111		return (0);
112	}
113
114	/*
115	 * If we don't have that symbol, then we have to simulate
116	 * "cp_time[]" by adding up the individual times for each CPU.
117	 */
118	maxcpu = kvm_getmaxcpu(kd);
119	if (maxcpu < 0)
120		return (-1);
121	for (i = 0; i < CPUSTATES; i++)
122		cp_time[i] = 0;
123	for (i = 0; i < maxcpu; i++) {
124		pc = kvm_getpcpu(kd, i);
125		if (pc == NULL)
126			continue;
127		if (pc == (void *)-1)
128			return (-1);
129		for (j = 0; j < CPUSTATES; j++)
130			cp_time[j] += pc->pc_cp_time[j];
131		free(pc);
132	}
133	return (0);
134}
135