aboutsummaryrefslogtreecommitdiff
path: root/lib/libkvm/kvm_cptime.c
blob: 9d303943f551c720d17ac64a420d76678ff56c3a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2008 Yahoo!, Inc.
 * All rights reserved.
 * Written by: John Baldwin <jhb@FreeBSD.org>
 *
 * 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.
 * 3. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * 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/param.h>
#include <sys/pcpu.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <kvm.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>

#include "kvm_private.h"

static struct nlist kvm_cp_time_nl[] = {
	{ .n_name = "_cp_time" },		/* (deprecated) */
	{ .n_name = NULL },
};

#define	NL_CP_TIME		0

static int kvm_cp_time_cached;

static int
_kvm_cp_time_init(kvm_t *kd)
{

	if (kvm_nlist(kd, kvm_cp_time_nl) < 0)
		return (-1);
	kvm_cp_time_cached = 1;
	return (0);
}

static int
getsysctl(kvm_t *kd, const char *name, void *buf, size_t len)
{
	size_t nlen;

	nlen = len;
	if (sysctlbyname(name, buf, &nlen, NULL, 0) < 0) {
		_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
		    strerror(errno));
		return (-1);
	}
	if (nlen != len) {
		_kvm_err(kd, kd->program, "sysctl %s has unexpected size",
		    name);
		return (-1);
	}
	return (0);
}

int
kvm_getcptime(kvm_t *kd, long *cp_time)
{
	struct pcpu *pc;
	int i, j, maxcpu;

	if (kd == NULL) {
		kvm_cp_time_cached = 0;
		return (0);
	}

	if (ISALIVE(kd))
		return (getsysctl(kd, "kern.cp_time", cp_time, sizeof(long) *
		    CPUSTATES));

	if (!kd->arch->ka_native(kd)) {
		_kvm_err(kd, kd->program,
		    "cannot read cp_time from non-native core");
		return (-1);
	}

	if (kvm_cp_time_cached == 0) {
		if (_kvm_cp_time_init(kd) < 0)
			return (-1);
	}

	/* If this kernel has a "cp_time[]" symbol, then just read that. */
	if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
		if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
		    sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
			_kvm_err(kd, kd->program, "cannot read cp_time array");
			return (-1);
		}
		return (0);
	}

	/*
	 * If we don't have that symbol, then we have to simulate
	 * "cp_time[]" by adding up the individual times for each CPU.
	 */
	maxcpu = kvm_getmaxcpu(kd);
	if (maxcpu < 0)
		return (-1);
	for (i = 0; i < CPUSTATES; i++)
		cp_time[i] = 0;
	for (i = 0; i < maxcpu; i++) {
		pc = kvm_getpcpu(kd, i);
		if (pc == NULL)
			continue;
		if (pc == (void *)-1)
			return (-1);
		for (j = 0; j < CPUSTATES; j++)
			cp_time[j] += pc->pc_cp_time[j];
		free(pc);
	}
	return (0);
}