freebsd-dev/usr.sbin/powerd/powerd.c
Nate Lawson 5883360b2f Import powerd(8), a utility for managing power consumption. Currently, it
just uses cpufreq(4) but in the future it should also do things like spin
down disks.  This is based on the work by Colin Percival (called "estctrl").
2005-02-26 21:17:31 +00:00

391 lines
9.3 KiB
C

/*-
* Copyright (c) 2004 Colin Percival
* Copyright (c) 2005 Nate Lawson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted providing that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <machine/apm_bios.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <sys/resource.h>
#define DEFAULT_ACTIVE_PERCENT 50
#define DEFAULT_IDLE_PERCENT 75
#define DEFAULT_POLL_INTERVAL 500
enum modes_t {
MODE_MIN,
MODE_ADAPTIVE,
MODE_MAX,
};
enum power_src_t {
SRC_AC,
SRC_BATTERY,
SRC_UNKNOWN,
};
const char *modes[] = {
"AC",
"battery",
"unknown"
};
#define ACPIAC "hw.acpi.acline"
#define APMDEV "/dev/apm"
static int read_usage_times(long *idle, long *total);
static int read_freqs(int *numfreqs, int **freqs);
static int set_freq(int freq);
static void parse_mode(char *arg, int *mode, int ch);
static void usage(void);
/* Sysctl data structures. */
static int cp_time_mib[2];
static int freq_mib[4];
static int levels_mib[4];
static int acline_mib[3];
/* Configuration */
static int cpu_running_mark;
static int cpu_idle_mark;
static int poll_ival;
static int
read_usage_times(long *idle, long *total)
{
static long idle_old, total_old;
long cp_time[CPUSTATES], i, total_new;
size_t cp_time_len;
int error;
cp_time_len = sizeof(cp_time);
error = sysctl(cp_time_mib, 2, cp_time, &cp_time_len, NULL, 0);
if (error)
return (error);
for (total_new = 0, i = 0; i < CPUSTATES; i++)
total_new += cp_time[i];
if (idle)
*idle = cp_time[CP_IDLE] - idle_old;
if (total)
*total = total_new - total_old;
idle_old = cp_time[CP_IDLE];
total_old = total_new;
return (0);
}
static int
read_freqs(int *numfreqs, int **freqs)
{
char *freqstr, *p, *q;
int i;
size_t len = 0;
if (sysctl(levels_mib, 4, NULL, &len, NULL, 0))
return (-1);
if ((freqstr = malloc(len)) == NULL)
return (-1);
if (sysctl(levels_mib, 4, freqstr, &len, NULL, 0))
return (-1);
*numfreqs = 1;
for (p = freqstr; *p != '\0'; p++)
if (*p == ' ')
(*numfreqs)++;
if ((*freqs = malloc(*numfreqs * sizeof(int))) == NULL) {
free(freqstr);
return (-1);
}
for (i = 0, p = freqstr; i < *numfreqs; i++) {
q = strchr(p, ' ');
if (q != NULL)
*q = '\0';
if (sscanf(p, "%d/%*d", &(*freqs)[i]) != 1) {
free(freqstr);
free(*freqs);
return (-1);
}
p = q + 1;
}
free(freqstr);
return (0);
}
static int
set_freq(int freq)
{
if (sysctl(freq_mib, 4, NULL, NULL, &freq, sizeof(freq)))
return (-1);
return (0);
}
static void
parse_mode(char *arg, int *mode, int ch)
{
if (strcmp(arg, "min") == 0)
*mode = MODE_MIN;
else if (strcmp(arg, "max") == 0)
*mode = MODE_MAX;
else if (strcmp(arg, "adaptive") == 0)
*mode = MODE_ADAPTIVE;
else
errx(1, "bad option: -%c %s", (char)ch, optarg);
}
static void
usage(void)
{
fprintf(stderr,
"usage: powerd [-v] [-a mode] [-b mode] [-i %%] [-n mode] [-p ival] [-r %%]\n");
exit(1);
}
int
main(int argc, char * argv[])
{
struct apm_info info;
long idle, total;
int apm_fd, curfreq, *freqs, i, numfreqs;
int ch, mode_ac, mode_battery, mode_none, acline, mode, vflag;
size_t len;
/* Default mode for all AC states is adaptive. */
mode_ac = mode_battery = mode_none = MODE_ADAPTIVE;
cpu_running_mark = DEFAULT_ACTIVE_PERCENT;
cpu_idle_mark = DEFAULT_IDLE_PERCENT;
poll_ival = DEFAULT_POLL_INTERVAL;
vflag = 0;
while ((ch = getopt(argc, argv, "a:b:i:n:p:r:v")) != EOF)
switch (ch) {
case 'a':
parse_mode(optarg, &mode_ac, ch);
break;
case 'b':
parse_mode(optarg, &mode_battery, ch);
break;
case 'i':
cpu_idle_mark = atoi(optarg);
if (cpu_idle_mark < 0 || cpu_idle_mark > 100) {
warnx("%d is not a valid percent",
cpu_idle_mark);
usage();
}
break;
case 'n':
parse_mode(optarg, &mode_none, ch);
break;
case 'p':
poll_ival = atoi(optarg);
if (poll_ival < 5) {
warnx("poll interval is in units of ms");
usage();
}
break;
case 'r':
cpu_running_mark = atoi(optarg);
if (cpu_running_mark < 0 || cpu_running_mark > 100) {
warnx("%d is not a valid percent",
cpu_running_mark);
usage();
}
break;
case 'v':
vflag = 1;
break;
default:
usage();
}
/* Poll interval is in units of ms. */
poll_ival *= 1000;
/* Look up various sysctl MIBs. */
len = 2;
if (sysctlnametomib("kern.cp_time", cp_time_mib, &len))
err(1, "lookup kern.cp_time");
len = 4;
if (sysctlnametomib("dev.cpu.0.freq", freq_mib, &len))
err(1, "lookup freq");
len = 4;
if (sysctlnametomib("dev.cpu.0.freq_levels", levels_mib, &len))
err(1, "lookup freq_levels");
/* Check if we can read the idle time and supported freqs. */
if (read_usage_times(NULL, NULL))
err(1, "read_usage_times");
if (read_freqs(&numfreqs, &freqs))
err(1, "error reading supported CPU frequencies");
/* Decide whether to use ACPI or APM to read the AC line status. */
len = sizeof(acline);
if (sysctlbyname(ACPIAC, &acline, &len, NULL, 0)) {
/* ACPI disabled, try APM */
apm_fd = open(APMDEV, O_RDONLY);
if (apm_fd == -1) {
warnx("cannot read AC line status, "
"using default settings");
}
} else {
len = 3;
if (sysctlnametomib(ACPIAC, acline_mib, &len))
err(1, "lookup acline");
apm_fd = -1;
}
/* Run in the background unless in verbose mode. */
if (!vflag)
daemon(0, 0);
/* Main loop. */
for (;;) {
/* Check status every few milliseconds. */
usleep(poll_ival);
/* Read the current AC status and record the mode. */
if (apm_fd != -1) {
if (ioctl(apm_fd, APMIO_GETINFO, &info) == -1)
acline = SRC_UNKNOWN;
else
acline = info.ai_acline ? SRC_AC : SRC_BATTERY;
} else {
len = sizeof(acline);
if (sysctl(acline_mib, 3, &acline, &len, NULL, 0))
acline = SRC_UNKNOWN;
else
acline = acline ? SRC_AC : SRC_BATTERY;
}
switch (acline) {
case SRC_AC:
mode = mode_ac;
break;
case SRC_BATTERY:
mode = mode_battery;
break;
case SRC_UNKNOWN:
mode = mode_none;
break;
default:
errx(1, "invalid AC line status %d", acline);
}
/* Read the current frequency. */
len = sizeof(curfreq);
if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0))
err(1, "error reading current CPU frequency");
/* Always switch to the lowest frequency in min mode. */
if (mode == MODE_MIN) {
if (curfreq != freqs[numfreqs - 1]) {
if (vflag) {
printf("now operating on %s power; "
"changing frequency to %d MHz\n",
modes[acline], freqs[numfreqs - 1]);
}
if (set_freq(freqs[numfreqs - 1]))
err(1, "error setting CPU freq %d",
freqs[numfreqs - 1]);
}
continue;
}
/* Always switch to the highest frequency in max mode. */
if (mode == MODE_MAX) {
if (curfreq != freqs[0]) {
if (vflag) {
printf("Now operating on %s power; "
"changing frequency to %d MHz\n",
modes[acline], freqs[0]);
}
if (set_freq(freqs[0]))
err(1, "error setting CPU freq %d",
freqs[0]);
}
continue;
}
/* Adaptive mode; get the current CPU usage times. */
if (read_usage_times(&idle, &total))
err(1, "read_usage_times");
/*
* If we're idle less than the active mark, jump the CPU to
* its fastest speed if we're not there yet. If we're idle
* more than the idle mark, drop down to the first setting
* that is half the current speed (exponential backoff).
*/
if (idle < (total * cpu_running_mark) / 100 &&
curfreq < freqs[0]) {
if (vflag) {
printf("idle time < %d%%, increasing clock"
" speed from %d MHz to %d MHz\n",
cpu_running_mark, curfreq, freqs[0]);
}
if (set_freq(freqs[0]))
err(1, "error setting CPU frequency %d",
freqs[0]);
} else if (idle > (total * cpu_idle_mark) / 100 &&
curfreq > freqs[numfreqs - 1]) {
for (i = 0; i < numfreqs - 1; i++) {
if (freqs[i] <= curfreq / 2)
break;
}
if (vflag) {
printf("idle time > %d%%, decreasing clock"
" speed from %d MHz to %d MHz\n",
cpu_idle_mark, curfreq, freqs[i]);
}
if (set_freq(freqs[i]))
err(1, "error setting CPU frequency %d",
freqs[i]);
}
}
/* NOTREACHED */
if (apm_fd != -1)
close(apm_fd);
exit(0);
}