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 #define _KERNEL_STRUCTURES
41 #include <sys/types.h>
42 #include <sys/sysctl.h>
43 #include <sys/kinfo.h>
51 static void usage(void);
52 static double getcputime(void);
53 static void acpi_setcpufreq(int nstate);
54 static void setupdominfo(void);
58 int CpuLimit; /* # of cpus at max frequency */
59 int DomLimit; /* # of domains at max frequency */
64 int CpuCount[256]; /* # of cpus in any given domain */
65 int CpuToDom[256]; /* domain a particular cpu belongs to */
67 double TriggerUp = 0.25;/* load per cpu to force max freq */
68 double TriggerDown; /* load per cpu to force the min freq */
70 static void sigintr(int signo);
73 main(int ac, char **av)
81 while ((ch = getopt(ac, av, "dp:tu:")) != -1) {
87 Hysteresis = (int)strtol(optarg, NULL, 10);
93 TriggerUp = (double)strtol(optarg, NULL, 10) / 100;
103 if (0 > Hysteresis || Hysteresis > 99) {
104 fprintf(stderr, "Invalid hysteresis value\n");
108 if (0 > TriggerUp || TriggerUp > 1) {
109 fprintf(stderr, "Invalid load limit value\n");
113 TriggerDown = TriggerUp - (TriggerUp * (double) Hysteresis / 100);
116 * Make sure powerd is not already running.
118 PowerFd = open("/var/run/powerd.pid", O_CREAT|O_RDWR, 0644);
121 "Cannot create /var/run/powerd.pid, "
122 "continuing anyway\n");
124 if (flock(PowerFd, LOCK_EX|LOCK_NB) < 0) {
125 fprintf(stderr, "powerd is already running\n");
131 * Demonize and set pid
135 openlog("powerd", LOG_CONS | LOG_PID, LOG_DAEMON);
139 ftruncate(PowerFd, 0);
140 snprintf(buf, sizeof(buf), "%d\n", (int)getpid());
141 write(PowerFd, buf, strlen(buf));
145 * Wait hw.acpi.cpu.px_dom* sysctl to be created by kernel
147 * Since hw.acpi.cpu.px_dom* creation is queued into ACPI
148 * taskqueue and ACPI taskqueue is shared across various
149 * ACPI modules, any delay in other modules may cause
150 * hw.acpi.cpu.px_dom* to be created at quite a later time
151 * (e.g. cmbat module's task could take quite a lot of time).
155 * Prime delta cputime calculation, make sure at least
162 if (DomBeg >= DomEnd) {
173 * Set to maximum performance if killed.
175 signal(SIGINT, sigintr);
176 signal(SIGTERM, sigintr);
181 * Calculate nstate, the number of cpus we wish to run at max
182 * frequency. All remaining cpus will be set to their lowest
183 * frequency and mapped out of the user process scheduler.
187 savg = (savg * 7.0 + qavg) / 8.0;
189 nstate = savg / TriggerUp;
190 if (nstate < CpuLimit)
191 nstate = savg / TriggerDown;
195 printf("\rqavg=%5.2f savg=%5.2f %2d/%2d ncpus=%d\r",
196 qavg, savg, CpuLimit, DomLimit, nstate);
199 if (nstate != CpuLimit)
200 acpi_setcpufreq(nstate);
207 sigintr(int signo __unused)
209 syslog(LOG_INFO, "killed, setting max and exiting");
210 acpi_setcpufreq(NCpus);
215 * Figure out the domains and calculate the CpuCount[] and CpuToDom[]
229 for (i = 0; i < 256; ++i) {
230 snprintf(buf, sizeof(buf),
231 "hw.acpi.cpu.px_dom%d.available", i);
232 if (sysctlbyname(buf, NULL, NULL, NULL, 0) >= 0)
237 for (i = 255; i >= DomBeg; --i) {
238 snprintf(buf, sizeof(buf),
239 "hw.acpi.cpu.px_dom%d.available", i);
240 if (sysctlbyname(buf, NULL, NULL, NULL, 0) >= 0) {
247 for (i = DomBeg; i < DomEnd; ++i) {
248 snprintf(buf, sizeof(buf),
249 "hw.acpi.cpu.px_dom%d.members", i);
250 msize = sizeof(members);
251 if (sysctlbyname(buf, members, &msize, NULL, 0) == 0) {
253 for (str = strtok(members, " "); str;
254 str = strtok(NULL, " ")) {
256 sscanf(str, "cpu%d", &n);
268 * Return the one-second cpu load. One cpu at 100% will return a value
269 * of 1.0. On a SMP system N cpus running at 100% will return a value of N.
275 static struct kinfo_cputime ocpu_time[64];
276 static struct kinfo_cputime ncpu_time[64];
282 bcopy(ncpu_time, ocpu_time, sizeof(ncpu_time));
283 slen = sizeof(ncpu_time);
284 if (sysctlbyname("kern.cputime", &ncpu_time, &slen, NULL, 0) < 0) {
285 fprintf(stderr, "kern.cputime sysctl not available\n");
288 ncpu = slen / sizeof(ncpu_time[0]);
291 for (cpu = 0; cpu < ncpu; ++cpu) {
292 delta += (ncpu_time[cpu].cp_user + ncpu_time[cpu].cp_sys +
293 ncpu_time[cpu].cp_nice + ncpu_time[cpu].cp_intr) -
294 (ocpu_time[cpu].cp_user + ocpu_time[cpu].cp_sys +
295 ocpu_time[cpu].cp_nice + ocpu_time[cpu].cp_intr);
297 return((double)delta / 1000000.0);
301 * nstate is the requested number of cpus that we wish to run at full
302 * frequency. We calculate how many domains we have to adjust to reach
305 * This function also sets the user scheduler global cpu mask.
309 acpi_setcpufreq(int nstate)
312 int increasing = (nstate > CpuLimit);
324 cpumask_t global_cpumask;
327 * Calculate the ending domain if the number of operating cpus
330 * Calculate the starting domain if the number of operating cpus
333 for (dom = DomBeg; dom < DomEnd; ++dom) {
336 ncpus += CpuCount[dom];
339 syslog(LOG_INFO, "using %d cpus", nstate);
342 * Set the mask of cpus the userland scheduler is allowed to use.
344 CPUMASK_ASSBMASK(global_cpumask, nstate);
345 sysctlbyname("kern.usched_global_cpumask", NULL, 0,
346 &global_cpumask, sizeof(global_cpumask));
359 * Adjust the cpu frequency
363 for (dom = domBeg; dom < domEnd; ++dom) {
365 * Retrieve availability list
367 asprintf(&sysid, "hw.acpi.cpu.px_dom%d.available", dom);
368 buflen = sizeof(buf) - 1;
369 v = sysctlbyname(sysid, buf, &buflen, NULL, 0);
376 * Parse out the highest and lowest cpu frequencies
379 highest = lowest = 0;
380 while (ptr && (v = strtol(ptr, &ptr, 10)) > 0) {
381 if (lowest == 0 || lowest > v)
383 if (highest == 0 || highest < v)
388 if ((highest - v == 1) && ! TurboOpt)
394 * Calculate the desired cpu frequency, test, and set.
396 desired = increasing ? highest : lowest;
398 asprintf(&sysid, "hw.acpi.cpu.px_dom%d.select", dom);
401 sysctlbyname(sysid, &v, &buflen, NULL, 0);
404 printf("dom%d set frequency %d\n",
407 sysctlbyname(sysid, NULL, NULL,
408 &desired, sizeof(desired));
418 fprintf(stderr, "usage: powerd [-dt] [-p hysteresis] [-u trigger_up]\n");