1 /*
2 * Copyright 2009, Intel Corporation
3 * Copyright 2009, Sun Microsystems, Inc
4 *
5 * This file is part of PowerTOP
6 *
7 * This program file is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program in a file named COPYING; if not, write to the
18 * Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor,
20 * Boston, MA 02110-1301 USA
21 *
22 * Authors:
23 * Arjan van de Ven <arjan@linux.intel.com>
24 * Eric C Saxe <eric.saxe@sun.com>
25 * Aubrey Li <aubrey.li@intel.com>
26 */
27
28 /*
29 * GPL Disclaimer
30 *
31 * For the avoidance of doubt, except that if any license choice other
32 * than GPL or LGPL is available it will apply instead, Sun elects to
33 * use only the General Public License version 2 (GPLv2) at this time
34 * for any software where a choice of GPL license versions is made
35 * available with the language indicating that GPLv2 or any later
36 * version may be used, or where a choice of which version of the GPL
37 * is applied is otherwise unspecified.
38 */
39
40 #include <stdlib.h>
41 #include <string.h>
42 #include <dtrace.h>
43 #include <kstat.h>
44 #include <errno.h>
45 #include "powertop.h"
46
47 /*
48 * Global turbo related variables definitions
49 */
50 boolean_t g_turbo_supported;
51 double g_turbo_ratio;
52
53 /*
54 * The variables to store kstat snapshot
55 */
56 static turbo_info_t *cpu_turbo_info = NULL;
57 static turbo_info_t *t_new = NULL;
58
59 /*
60 * Perform setup necessary to enumerate and track CPU turbo information
61 */
62 static int
pt_turbo_init(void)63 pt_turbo_init(void)
64 {
65 kstat_ctl_t *kc;
66 kstat_t *ksp;
67 kstat_named_t *knp;
68
69 /*
70 * check if the CPU turbo is supported
71 */
72 if ((kc = kstat_open()) == NULL) {
73 g_turbo_supported = B_FALSE;
74 return (errno);
75 }
76
77 ksp = kstat_lookup(kc, "turbo", 0, NULL);
78 if (ksp == NULL) {
79 g_turbo_supported = B_FALSE;
80 (void) kstat_close(kc);
81 return (-1);
82 }
83
84 (void) kstat_read(kc, ksp, NULL);
85
86 knp = kstat_data_lookup(ksp, "turbo_supported");
87 if (knp == NULL) {
88 pt_error("couldn't find 'turbo_supported' kstat\n");
89 g_turbo_supported = B_FALSE;
90 (void) kstat_close(kc);
91 return (-2);
92 }
93
94 /*
95 * Initialize turbo information structure if turbo mode is supported
96 */
97 if (knp->value.ui32) {
98 g_turbo_supported = B_TRUE;
99 cpu_turbo_info = calloc((size_t)g_ncpus, sizeof (turbo_info_t));
100 t_new = calloc((size_t)g_ncpus, sizeof (turbo_info_t));
101 }
102
103 (void) kstat_close(kc);
104 return (0);
105 }
106
107 /*
108 * Take a snapshot of each CPU's turbo information
109 * by looking through the turbo kstats.
110 */
111 static int
pt_turbo_snapshot(turbo_info_t * turbo_snapshot)112 pt_turbo_snapshot(turbo_info_t *turbo_snapshot)
113 {
114 kstat_ctl_t *kc;
115 kstat_t *ksp;
116 kstat_named_t *knp;
117 int cpu;
118 turbo_info_t *turbo_info;
119
120 if ((kc = kstat_open()) == NULL)
121 return (errno);
122
123 for (cpu = 0; cpu < g_ncpus; cpu++) {
124 turbo_info = &turbo_snapshot[cpu];
125 ksp = kstat_lookup(kc, "turbo", g_cpu_table[cpu], NULL);
126 if (ksp == NULL) {
127 pt_error("couldn't find 'turbo' kstat for CPU %d\n",
128 cpu);
129 (void) kstat_close(kc);
130 return (-1);
131 }
132
133 if (kstat_read(kc, ksp, NULL) == -1) {
134 pt_error("couldn't read 'turbo' kstat for CPU %d\n",
135 cpu);
136 (void) kstat_close(kc);
137 return (-2);
138 }
139
140 knp = kstat_data_lookup(ksp, "turbo_mcnt");
141 if (knp == NULL) {
142 pt_error("couldn't find 'turbo_mcnt' kstat for CPU "
143 "%d\n", cpu);
144 (void) kstat_close(kc);
145 return (-3);
146 }
147
148 /*
149 * snapshot IA32_MPERF_MSR
150 */
151 turbo_info->t_mcnt = knp->value.ui64;
152
153 knp = kstat_data_lookup(ksp, "turbo_acnt");
154 if (knp == NULL) {
155 pt_error("couldn't find 'turbo_acnt' kstat for CPU "
156 "%d\n", cpu);
157 (void) kstat_close(kc);
158 return (-4);
159 }
160
161 /*
162 * snapshot IA32_APERF_MSR
163 */
164 turbo_info->t_acnt = knp->value.ui64;
165 }
166
167 if (kstat_close(kc) != 0)
168 pt_error("couldn't close 'turbo' kstat\n");
169
170 return (0);
171 }
172
173 /*
174 * Turbo support checking and information initialization
175 */
176 int
pt_turbo_stat_prepare(void)177 pt_turbo_stat_prepare(void)
178 {
179 int ret = 0;
180
181 if ((ret = pt_turbo_init()) != 0)
182 return (ret);
183
184 if ((ret = pt_turbo_snapshot(cpu_turbo_info)) != 0)
185 pt_error("failed to snapshot 'turbo' kstat\n");
186
187 return (ret);
188 }
189
190 /*
191 * When doing the statistics collection, we compare two kstat snapshot
192 * and get a delta. the final ratio of performance boost will be worked
193 * out according to the kstat delta
194 */
195 int
pt_turbo_stat_collect(void)196 pt_turbo_stat_collect(void)
197 {
198 int cpu;
199 uint64_t delta_mcnt, delta_acnt;
200 double ratio;
201 int ret;
202
203 /*
204 * Take a snapshot of turbo information to setup turbo_info_t
205 * structure
206 */
207 if ((ret = pt_turbo_snapshot(t_new)) != 0) {
208 pt_error("failed to snapshot 'turbo' kstat\n");
209 return (ret);
210 }
211
212 /*
213 * Calculate the kstat delta and work out the performance boost ratio
214 */
215 for (cpu = 0; cpu < g_ncpus; cpu++) {
216 delta_mcnt = t_new[cpu].t_mcnt - cpu_turbo_info[cpu].t_mcnt;
217 delta_acnt = t_new[cpu].t_acnt - cpu_turbo_info[cpu].t_acnt;
218
219 if ((delta_mcnt > delta_acnt) || (delta_mcnt == 0))
220 ratio = 1.0;
221 else
222 ratio = (double)delta_acnt / (double)delta_mcnt;
223 g_turbo_ratio += ratio;
224 }
225
226 g_turbo_ratio = g_turbo_ratio / (double)g_ncpus;
227
228 /*
229 * Update the structure of the kstat for the next time calculation
230 */
231 (void) memcpy(cpu_turbo_info, t_new, g_ncpus * (sizeof (turbo_info_t)));
232
233 return (0);
234 }
235