2 * Copyright (c) 2010 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * The powerd daemon monitors the cpu load and adjusts cpu frequencies
37 * via hw.acpi.cpu.px_dom*.
40 #include <sys/types.h>
41 #include <sys/sysctl.h>
42 #include <sys/kinfo.h>
50 #define STATE_UNKNOWN 0
54 static void usage(void);
55 static double getcputime(void);
56 static void acpi_setcpufreq(int ostate, int nstate);
59 int PowerState = STATE_UNKNOWN;
61 double Trigger = 0.25;
64 main(int ac, char **av)
72 while ((ch = getopt(ac, av, "d")) != -1) {
86 * Prime delta cputime calculation, make sure at least dom0 exists,
87 * and make sure powerd is not already running.
92 if (sysctlbyname("hw.acpi.cpu.px_dom0.available", NULL, NULL,
94 fprintf(stderr, "hw.acpi.cpu.px_dom* sysctl not available\n");
98 PowerFd = open("/var/run/powerd.pid", O_CREAT|O_RDWR, 0644);
101 "Cannot create /var/run/powerd.pid, "
102 "continuing anyway\n");
104 if (flock(PowerFd, LOCK_EX|LOCK_NB) < 0) {
105 fprintf(stderr, "powerd is already running\n");
111 * Demonize and set pid
115 openlog("powerd", LOG_CONS | LOG_PID, LOG_DAEMON);
119 ftruncate(PowerFd, 0);
120 snprintf(buf, sizeof(buf), "%d\n", (int)getpid());
121 write(PowerFd, buf, strlen(buf));
129 savg = (savg * 7.0 + qavg) / 8.0;
132 printf("\rqavg=%5.2f savg=%5.2f\r", qavg, savg);
137 if (nstate == STATE_UNKNOWN) {
142 } else if (nstate == STATE_LOW) {
143 if (savg >= Trigger || qavg >= 0.9)
146 if (savg < Trigger / 2.0 && qavg < Trigger / 2.0)
149 if (PowerState != nstate) {
150 acpi_setcpufreq(PowerState, nstate);
158 * Return the one-second cpu load. One cpu at 100% will return a value
159 * of 1.0. On a SMP system N cpus running at 100% will return a value of N.
165 static struct kinfo_cputime ocpu_time[64];
166 static struct kinfo_cputime ncpu_time[64];
172 bcopy(ncpu_time, ocpu_time, sizeof(ncpu_time));
173 slen = sizeof(ncpu_time);
174 if (sysctlbyname("kern.cputime", &ncpu_time, &slen, NULL, 0) < 0) {
175 fprintf(stderr, "kern.cputime sysctl not available\n");
178 ncpu = slen / sizeof(ncpu_time[0]);
181 for (cpu = 0; cpu < ncpu; ++cpu) {
182 delta += (ncpu_time[cpu].cp_user + ncpu_time[cpu].cp_sys +
183 ncpu_time[cpu].cp_intr) -
184 (ocpu_time[cpu].cp_user + ocpu_time[cpu].cp_sys +
185 ocpu_time[cpu].cp_intr);
187 return((double)delta / 1000000.0);
193 acpi_setcpufreq(int ostate, int nstate)
208 * Retrieve availability list
210 asprintf(&sysid, "hw.acpi.cpu.px_dom%d.available", dom);
211 buflen = sizeof(buf) - 1;
212 v = sysctlbyname(sysid, buf, &buflen, NULL, 0);
219 * Parse out the highest and lowest cpu frequencies
222 highest = lowest = 0;
223 while (ptr && (v = strtol(ptr, &ptr, 10)) > 0) {
224 if (lowest == 0 || lowest > v)
226 if (highest == 0 || highest < v)
231 * Calculate the desired cpu frequency, test, and set.
233 desired = (nstate == STATE_LOW) ? lowest : highest;
235 asprintf(&sysid, "hw.acpi.cpu.px_dom%d.select", dom);
238 sysctlbyname(sysid, &v, &buflen, NULL, 0);
239 if (v != desired || ostate == STATE_UNKNOWN) {
241 printf("dom%d set frequency %d\n",
244 syslog(LOG_INFO, "dom%d set frequency %d\n",
247 sysctlbyname(sysid, NULL, NULL,
248 &desired, sizeof(desired));
259 fprintf(stderr, "usage: powerd [-d]\n");