freebsd-dev/usr.sbin/powerd/powerd.c
Nate Lawson 2f8ad6c087 Drop the default running value to 60% from 80%. Testing shows that we
cycle too much, wasting power if we trigger a jump to full speed too
easily.  CPU-bound tasks quickly push idle below this level.
2005-04-10 20:42:55 +00:00

457 lines
11 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 <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef __i386__
#include <machine/apm_bios.h>
#endif
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <sys/resource.h>
#define DEFAULT_ACTIVE_PERCENT 65
#define DEFAULT_IDLE_PERCENT 90
#define DEFAULT_POLL_INTERVAL 500 /* Poll interval in milliseconds */
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, int **power);
static int set_freq(int freq);
static void acline_init(void);
static int acline_read(void);
static void handle_sigs(int sig);
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 apm_fd;
static int exit_requested;
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, int **power)
{
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);
}
if ((*power = malloc(*numfreqs * sizeof(int))) == NULL) {
free(freqstr);
free(*freqs);
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], &(*power)[i]) != 2) {
free(freqstr);
free(*freqs);
free(*power);
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);
}
/*
* Try to use ACPI to find the AC line status. If this fails, fall back
* to APM. If nothing succeeds, we'll just run in default mode.
*/
static void
acline_init()
{
int acline;
size_t len;
apm_fd = -1;
len = sizeof(acline);
if (sysctlbyname(ACPIAC, &acline, &len, NULL, 0) == 0) {
len = 3;
if (sysctlnametomib(ACPIAC, acline_mib, &len))
err(1, "lookup acline");
} else {
apm_fd = open(APMDEV, O_RDONLY);
if (apm_fd == -1)
warnx(
"cannot read AC line status, using default settings");
}
}
static int
acline_read()
{
int acline = SRC_UNKNOWN;
size_t len;
#ifdef __i386__
struct apm_info info;
if (apm_fd != -1 && ioctl(apm_fd, APMIO_GETINFO, &info) == 0)
acline = info.ai_acline ? SRC_AC : SRC_BATTERY;
#endif
if (acline == SRC_UNKNOWN) {
len = sizeof(acline);
if (sysctl(acline_mib, 3, &acline, &len, NULL, 0) == 0)
acline = acline ? SRC_AC : SRC_BATTERY;
}
return (acline);
}
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
handle_sigs(int __unused sig)
{
exit_requested = 1;
}
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[])
{
long idle, total;
int curfreq, *freqs, i, *mwatts, numfreqs;
int ch, mode_ac, mode_battery, mode_none, acline, mode, vflag;
uint64_t mjoules_used;
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;
mjoules_used = 0;
vflag = 0;
apm_fd = -1;
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, &mwatts))
err(1, "error reading supported CPU frequencies");
/* Decide whether to use ACPI or APM to read the AC line status. */
acline_init();
/* Run in the background unless in verbose mode. */
if (!vflag)
daemon(0, 0);
signal(SIGINT, handle_sigs);
signal(SIGTERM, handle_sigs);
/* Main loop. */
for (;;) {
/* Check status every few milliseconds. */
usleep(poll_ival);
/* If the user requested we quit, print some statistics. */
if (exit_requested) {
if (vflag && mjoules_used != 0)
printf("total joules used: %u.%03u\n",
(u_int)(mjoules_used / 1000),
(int)mjoules_used % 1000);
break;
}
/* Read the current AC status and record the mode. */
acline = acline_read();
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");
if (vflag) {
for (i = 0; i < numfreqs; i++) {
if (freqs[i] == curfreq)
break;
}
/* Keep a sum of all power actually used. */
if (i < numfreqs && mwatts[i] != -1)
mjoules_used +=
(mwatts[i] * (poll_ival / 1000)) / 1000;
}
/* 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]);
}
}
free(freqs);
free(mwatts);
exit(0);
}