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/param.h>
34 #include <sys/pcpu.h>
35 #include <sys/resource.h>
36 #include <sys/sysctl.h>
37 #include <errno.h>
38 #include <kvm.h>
39 #include <limits.h>
40 #include <stdlib.h>
41 #include <string.h>
42
43 #include "kvm_private.h"
44
45 static struct nlist kvm_cp_time_nl[] = {
46 { .n_name = "_cp_time" }, /* (deprecated) */
47 { .n_name = NULL },
48 };
49
50 #define NL_CP_TIME 0
51
52 static int kvm_cp_time_cached;
53
54 static int
_kvm_cp_time_init(kvm_t * kd)55 _kvm_cp_time_init(kvm_t *kd)
56 {
57
58 if (kvm_nlist(kd, kvm_cp_time_nl) < 0)
59 return (-1);
60 kvm_cp_time_cached = 1;
61 return (0);
62 }
63
64 static int
getsysctl(kvm_t * kd,const char * name,void * buf,size_t len)65 getsysctl(kvm_t *kd, const char *name, void *buf, size_t len)
66 {
67 size_t nlen;
68
69 nlen = len;
70 if (sysctlbyname(name, buf, &nlen, NULL, 0) < 0) {
71 _kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
72 strerror(errno));
73 return (-1);
74 }
75 if (nlen != len) {
76 _kvm_err(kd, kd->program, "sysctl %s has unexpected size",
77 name);
78 return (-1);
79 }
80 return (0);
81 }
82
83 int
kvm_getcptime(kvm_t * kd,long * cp_time)84 kvm_getcptime(kvm_t *kd, long *cp_time)
85 {
86 struct pcpu *pc;
87 int i, j, maxcpu;
88
89 if (kd == NULL) {
90 kvm_cp_time_cached = 0;
91 return (0);
92 }
93
94 if (ISALIVE(kd))
95 return (getsysctl(kd, "kern.cp_time", cp_time, sizeof(long) *
96 CPUSTATES));
97
98 if (!kd->arch->ka_native(kd)) {
99 _kvm_err(kd, kd->program,
100 "cannot read cp_time from non-native core");
101 return (-1);
102 }
103
104 if (kvm_cp_time_cached == 0) {
105 if (_kvm_cp_time_init(kd) < 0)
106 return (-1);
107 }
108
109 /* If this kernel has a "cp_time[]" symbol, then just read that. */
110 if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
111 if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
112 sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
113 _kvm_err(kd, kd->program, "cannot read cp_time array");
114 return (-1);
115 }
116 return (0);
117 }
118
119 /*
120 * If we don't have that symbol, then we have to simulate
121 * "cp_time[]" by adding up the individual times for each CPU.
122 */
123 maxcpu = kvm_getmaxcpu(kd);
124 if (maxcpu < 0)
125 return (-1);
126 for (i = 0; i < CPUSTATES; i++)
127 cp_time[i] = 0;
128 for (i = 0; i < maxcpu; i++) {
129 pc = kvm_getpcpu(kd, i);
130 if (pc == NULL)
131 continue;
132 if (pc == (void *)-1)
133 return (-1);
134 for (j = 0; j < CPUSTATES; j++)
135 cp_time[j] += pc->pc_cp_time[j];
136 free(pc);
137 }
138 return (0);
139 }
140