1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2008 Yahoo!, Inc.
5 * All rights reserved.
6 * Written by: John Baldwin <jhb@FreeBSD.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
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
46 static 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
53 static int kvm_cp_time_cached;
54
55 static int
_kvm_cp_time_init(kvm_t * kd)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
65 static int
getsysctl(kvm_t * kd,const char * name,void * buf,size_t len)66 getsysctl(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
84 int
kvm_getcptime(kvm_t * kd,long * cp_time)85 kvm_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 (!kd->arch->ka_native(kd)) {
100 _kvm_err(kd, kd->program,
101 "cannot read cp_time from non-native core");
102 return (-1);
103 }
104
105 if (kvm_cp_time_cached == 0) {
106 if (_kvm_cp_time_init(kd) < 0)
107 return (-1);
108 }
109
110 /* If this kernel has a "cp_time[]" symbol, then just read that. */
111 if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
112 if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
113 sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
114 _kvm_err(kd, kd->program, "cannot read cp_time array");
115 return (-1);
116 }
117 return (0);
118 }
119
120 /*
121 * If we don't have that symbol, then we have to simulate
122 * "cp_time[]" by adding up the individual times for each CPU.
123 */
124 maxcpu = kvm_getmaxcpu(kd);
125 if (maxcpu < 0)
126 return (-1);
127 for (i = 0; i < CPUSTATES; i++)
128 cp_time[i] = 0;
129 for (i = 0; i < maxcpu; i++) {
130 pc = kvm_getpcpu(kd, i);
131 if (pc == NULL)
132 continue;
133 if (pc == (void *)-1)
134 return (-1);
135 for (j = 0; j < CPUSTATES; j++)
136 cp_time[j] += pc->pc_cp_time[j];
137 free(pc);
138 }
139 return (0);
140 }
141