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,
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27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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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 */
66 int Hysteresis = 10; /* percentage */
67 double TriggerUp = 0.25;/* single-cpu load 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)
76 double uavg; /* uavg - used for speeding up */
77 double davg; /* davg - used for slowing down */
86 srt = 8.0; /* time for samples - 8 seconds */
87 pollrate = 1.0; /* polling rate in seconds */
89 while ((ch = getopt(ac, av, "dp:r:tu:T:")) != -1) {
95 Hysteresis = (int)strtol(optarg, NULL, 10);
101 TriggerUp = (double)strtol(optarg, NULL, 10) / 100;
104 pollrate = strtod(optarg, NULL);
107 srt = strtod(optarg, NULL);
117 if (0 > Hysteresis || Hysteresis > 99) {
118 fprintf(stderr, "Invalid hysteresis value\n");
122 if (0 > TriggerUp || TriggerUp > 1) {
123 fprintf(stderr, "Invalid load limit value\n");
127 TriggerDown = TriggerUp - (TriggerUp * (double) Hysteresis / 100);
130 * Make sure powerd is not already running.
132 PowerFd = open("/var/run/powerd.pid", O_CREAT|O_RDWR, 0644);
135 "Cannot create /var/run/powerd.pid, "
136 "continuing anyway\n");
138 if (flock(PowerFd, LOCK_EX|LOCK_NB) < 0) {
139 fprintf(stderr, "powerd is already running\n");
145 * Demonize and set pid
149 openlog("powerd", LOG_CONS | LOG_PID, LOG_DAEMON);
153 ftruncate(PowerFd, 0);
154 snprintf(buf, sizeof(buf), "%d\n", (int)getpid());
155 write(PowerFd, buf, strlen(buf));
159 * Wait hw.acpi.cpu.px_dom* sysctl to be created by kernel
161 * Since hw.acpi.cpu.px_dom* creation is queued into ACPI
162 * taskqueue and ACPI taskqueue is shared across various
163 * ACPI modules, any delay in other modules may cause
164 * hw.acpi.cpu.px_dom* to be created at quite a later time
165 * (e.g. cmbat module's task could take quite a lot of time).
169 * Prime delta cputime calculation, make sure at least
175 if (DomBeg >= DomEnd) {
176 usleep((int)(pollrate * 1000000.0));
186 * Set to maximum performance if killed.
188 signal(SIGINT, sigintr);
189 signal(SIGTERM, sigintr);
193 srt = srt / pollrate; /* convert to sample count */
196 printf("samples for downgrading: %5.2f\n", srt);
201 * Calculate nstate, the number of cpus we wish to run at max
202 * frequency. All remaining cpus will be set to their lowest
203 * frequency and mapped out of the user process scheduler.
207 uavg = (uavg * 2.0 + qavg) / 3.0; /* speeding up */
208 davg = (davg * srt + qavg) / (srt + 1); /* slowing down */
212 ustate = uavg / TriggerUp;
213 if (ustate < CpuLimit)
214 ustate = uavg / TriggerDown;
215 dstate = davg / TriggerUp;
216 if (dstate < CpuLimit)
217 dstate = davg / TriggerDown;
219 nstate = (ustate > dstate) ? ustate : dstate;
224 printf("\rqavg=%5.2f uavg=%5.2f davg=%5.2f "
225 "%2d/%2d ncpus=%d\r",
227 CpuLimit, DomLimit, nstate);
230 if (nstate != CpuLimit)
231 acpi_setcpufreq(nstate);
232 usleep((int)(pollrate * 1000000.0));
238 sigintr(int signo __unused)
240 syslog(LOG_INFO, "killed, setting max and exiting");
241 acpi_setcpufreq(NCpus);
246 * Figure out the domains and calculate the CpuCount[] and CpuToDom[]
260 for (i = 0; i < 256; ++i) {
261 snprintf(buf, sizeof(buf),
262 "hw.acpi.cpu.px_dom%d.available", i);
263 if (sysctlbyname(buf, NULL, NULL, NULL, 0) >= 0)
268 for (i = 255; i >= DomBeg; --i) {
269 snprintf(buf, sizeof(buf),
270 "hw.acpi.cpu.px_dom%d.available", i);
271 if (sysctlbyname(buf, NULL, NULL, NULL, 0) >= 0) {
278 for (i = DomBeg; i < DomEnd; ++i) {
279 snprintf(buf, sizeof(buf),
280 "hw.acpi.cpu.px_dom%d.members", i);
281 msize = sizeof(members);
282 if (sysctlbyname(buf, members, &msize, NULL, 0) == 0) {
284 for (str = strtok(members, " "); str;
285 str = strtok(NULL, " ")) {
287 sscanf(str, "cpu%d", &n);
299 * Return the one-second cpu load. One cpu at 100% will return a value
300 * of 1.0. On a SMP system N cpus running at 100% will return a value of N.
306 static struct kinfo_cputime ocpu_time[64];
307 static struct kinfo_cputime ncpu_time[64];
313 bcopy(ncpu_time, ocpu_time, sizeof(ncpu_time));
314 slen = sizeof(ncpu_time);
315 if (sysctlbyname("kern.cputime", &ncpu_time, &slen, NULL, 0) < 0) {
316 fprintf(stderr, "kern.cputime sysctl not available\n");
319 ncpu = slen / sizeof(ncpu_time[0]);
322 for (cpu = 0; cpu < ncpu; ++cpu) {
323 delta += (ncpu_time[cpu].cp_user + ncpu_time[cpu].cp_sys +
324 ncpu_time[cpu].cp_nice + ncpu_time[cpu].cp_intr) -
325 (ocpu_time[cpu].cp_user + ocpu_time[cpu].cp_sys +
326 ocpu_time[cpu].cp_nice + ocpu_time[cpu].cp_intr);
328 return((double)delta / 1000000.0);
332 * nstate is the requested number of cpus that we wish to run at full
333 * frequency. We calculate how many domains we have to adjust to reach
336 * This function also sets the user scheduler global cpu mask.
340 acpi_setcpufreq(int nstate)
343 int increasing = (nstate > CpuLimit);
355 cpumask_t global_cpumask;
358 * Calculate the ending domain if the number of operating cpus
361 * Calculate the starting domain if the number of operating cpus
364 for (dom = DomBeg; dom < DomEnd; ++dom) {
367 ncpus += CpuCount[dom];
370 syslog(LOG_INFO, "using %d cpus", nstate);
373 * Set the mask of cpus the userland scheduler is allowed to use.
375 CPUMASK_ASSBMASK(global_cpumask, nstate);
376 sysctlbyname("kern.usched_global_cpumask", NULL, 0,
377 &global_cpumask, sizeof(global_cpumask));
390 * Adjust the cpu frequency
394 for (dom = domBeg; dom < domEnd; ++dom) {
396 * Retrieve availability list
398 asprintf(&sysid, "hw.acpi.cpu.px_dom%d.available", dom);
399 buflen = sizeof(buf) - 1;
400 v = sysctlbyname(sysid, buf, &buflen, NULL, 0);
407 * Parse out the highest and lowest cpu frequencies
410 highest = lowest = 0;
411 while (ptr && (v = strtol(ptr, &ptr, 10)) > 0) {
412 if (lowest == 0 || lowest > v)
414 if (highest == 0 || highest < v)
419 if ((highest - v == 1) && ! TurboOpt)
425 * Calculate the desired cpu frequency, test, and set.
427 desired = increasing ? highest : lowest;
429 asprintf(&sysid, "hw.acpi.cpu.px_dom%d.select", dom);
432 sysctlbyname(sysid, &v, &buflen, NULL, 0);
435 printf("dom%d set frequency %d\n",
438 sysctlbyname(sysid, NULL, NULL,
439 &desired, sizeof(desired));
449 fprintf(stderr, "usage: powerd [-dt] [-p hysteresis] [-u trigger_up]\n");