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Set of powerd enchancements:

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1. Make it more SMP polite. Previous version uses average CPU load that
often leads to load underestimation. It make powerd with default
configuration unusable on systems with more then 2 CPUs. I propose to use
summary load instead of average one. IMO this is the best we can do without
specially tuned scheduler. Also as soon as measuring total load on SMP
systems is more useful then total idle, I have switched to it.

2. Make powerd's operation independent from number and size of frequency
levels. I have added internal frequency counter which translated into real
frequencies only on a last stage and only as good as gone. Some systems may
have only several power levels, while others - many of them, so adaptation
time with previous approach was completely different.

3. As part of previous I have changed adaptive mode to rise frequency on
demand up to 2 times and fall on 1/8 per time internal.

4. For desktop (AC-powered) systems I have added one more mode - "hiadaptive".
It rises frequency twice faster, drops it 4 times slower, prefers twice
lower CPU load and has additional delay before leaving the highest frequency
after the period of maximum load. This mode was specially made to improve
interactivity of the systems where operation capabilities are more
significant then power consumption, but keeping maximum frequency all the
time is not needed.

5. I have reduced default polling interval from 1/2 to 1/4 of second.
It is not so important for algorithm math now, but gives better system
interactivity.

Discussed on:	mobile@
This commit is contained in:
mav 2008-11-18 13:24:38 +00:00
parent ca9ebe8c73
commit faa047f97d
2 changed files with 154 additions and 89 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
usr.sbin/powerd/powerd.8
View File

@ -47,7 +47,8 @@ utility monitors the system state and sets various power control options
accordingly.
It offers three modes (maximum, minimum, and adaptive) that can be
individually selected while on AC power or batteries.
The modes maximum, minimum, and adaptive may be abbreviated max, min, adp.
The modes maximum, minimum, adaptive and hiadaptive may be abbreviated
max, min, adp, hadp.
.Pp
Maximum mode chooses the highest performance values.
Minimum mode selects the lowest performance values to get the most power
@ -56,8 +57,10 @@ Adaptive mode attempts to strike a balance by degrading performance when
the system appears idle and increasing it when the system is busy.
It offers a good balance between a small performance loss for greatly
increased power savings.
The default mode is
adaptive.
Hiadaptive mode is alike adaptive mode, but tuned for systems where
performance and interactivity are more important then power consumption.
It rises frequency faster, drops slower and keeps twice lower CPU load.
The default mode is adaptive for battery power and hiadaptive for the rest.
.Pp
The
.Nm
@ -72,10 +75,9 @@ Selects the
.Ar mode
to use while on battery power.
.It Fl i Ar percent
Specifies the CPU idle percent level when
adaptive
Specifies the CPU load percent level when adaptive
mode should begin to degrade performance to save power.
The default is 90% or higher.
The default is 50% or lower.
.It Fl n Ar mode
Selects the
.Ar mode
@ -83,16 +85,15 @@ to use normally when the AC line state is unknown.
.It Fl p Ar ival
Specifies a different polling interval (in milliseconds) for AC line state
and system idle levels.
The default is 500 ms.
The default is 250 ms.
.It Fl P Ar pidfile
Specifies an alternative file in which the process ID should be stored.
The default is
.Pa /var/run/powerd.pid .
.It Fl r Ar percent
Specifies the CPU idle percent level where
adaptive
Specifies the CPU load percent level where adaptive
mode should consider the CPU running and increase performance.
The default is 65% or lower.
The default is 75% or higther.
.It Fl v
Verbose mode.
Messages about power changes will be printed to stdout and

222
usr.sbin/powerd/powerd.c
View File

@ -50,13 +50,14 @@ __FBSDID("$FreeBSD$");
#include <machine/apm_bios.h>
#endif
#define DEFAULT_ACTIVE_PERCENT 65
#define DEFAULT_IDLE_PERCENT 90
#define DEFAULT_POLL_INTERVAL 500 /* Poll interval in milliseconds */
#define DEFAULT_ACTIVE_PERCENT 75
#define DEFAULT_IDLE_PERCENT 50
#define DEFAULT_POLL_INTERVAL 250 /* Poll interval in milliseconds */
typedef enum {
MODE_MIN,
MODE_ADAPTIVE,
MODE_HIADAPTIVE,
MODE_MAX,
} modes_t;
@ -77,7 +78,7 @@ const char *modes[] = {
#define DEVDPIPE "/var/run/devd.pipe"
#define DEVCTL_MAXBUF 1024
static int read_usage_times(long *idle, long *total);
static int read_usage_times(int *load);
static int read_freqs(int *numfreqs, int **freqs, int **power);
static int set_freq(int freq);
static void acline_init(void);
@ -89,7 +90,7 @@ 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 cp_times_mib[2];
static int freq_mib[4];
static int levels_mib[4];
static int acline_mib[3];
@ -119,27 +120,49 @@ static int devd_pipe = -1;
static struct timeval tried_devd;
static int
read_usage_times(long *idle, long *total)
read_usage_times(int *load)
{
static long idle_old, total_old;
long cp_time[CPUSTATES], i, total_new;
size_t cp_time_len;
int error;
static long *cp_times = NULL, *cp_times_old = NULL;
static int ncpus = 0;
size_t cp_times_len;
int error, cpu, i, total;
cp_time_len = sizeof(cp_time);
error = sysctl(cp_time_mib, 2, cp_time, &cp_time_len, NULL, 0);
if (cp_times == NULL) {
cp_times_len = 0;
error = sysctl(cp_times_mib, 2, NULL, &cp_times_len, NULL, 0);
if (error)
return (error);
if ((cp_times = malloc(cp_times_len)) == NULL)
return (errno);
if ((cp_times_old = malloc(cp_times_len)) == NULL) {
free(cp_times);
cp_times = NULL;
return (errno);
}
ncpus = cp_times_len / (sizeof(long) * CPUSTATES);
}
cp_times_len = sizeof(long) * CPUSTATES * ncpus;
error = sysctl(cp_times_mib, 2, cp_times, &cp_times_len, NULL, 0);
if (error)
return (error);
for (total_new = 0, i = 0; i < CPUSTATES; i++)
total_new += cp_time[i];
if (load) {
*load = 0;
for (cpu = 0; cpu < ncpus; cpu++) {
total = 0;
for (i = 0; i < CPUSTATES; i++) {
total += cp_times[cpu * CPUSTATES + i] -
cp_times_old[cpu * CPUSTATES + i];
}
if (total == 0)
continue;
*load += 100 - (cp_times[cpu * CPUSTATES + CP_IDLE] -
cp_times_old[cpu * CPUSTATES + CP_IDLE]) * 100 / total;
}
}
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;
memcpy(cp_times_old, cp_times, cp_times_len);
return (0);
}
@ -189,6 +212,21 @@ read_freqs(int *numfreqs, int **freqs, int **power)
return (0);
}
static int
get_freq(void)
{
size_t len;
int curfreq;
len = sizeof(curfreq);
if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0) != 0) {
if (vflag)
warn("error reading current CPU frequency");
curfreq = 0;
}
return (curfreq);
}
static int
set_freq(int freq)
{
@ -201,6 +239,19 @@ set_freq(int freq)
return (0);
}
static int
get_freq_id(int freq, int *freqs, int numfreqs)
{
int i = 1;
while (i < numfreqs) {
if (freqs[i] < freq)
break;
i++;
}
return (i - 1);
}
/*
* 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.
@ -341,6 +392,8 @@ parse_mode(char *arg, int *mode, int ch)
*mode = MODE_MAX;
else if (strcmp(arg, "adaptive") == 0 || strcmp(arg, "adp") == 0)
*mode = MODE_ADAPTIVE;
else if (strcmp(arg, "hiadaptive") == 0 || strcmp(arg, "hadp") == 0)
*mode = MODE_HIADAPTIVE;
else
errx(1, "bad option: -%c %s", (char)ch, optarg);
}
@ -369,14 +422,14 @@ main(int argc, char * argv[])
int nfds;
struct pidfh *pfh = NULL;
const char *pidfile = NULL;
long idle, total;
int curfreq, *freqs, i, *mwatts, numfreqs;
int freq, curfreq, *freqs, i, j, *mwatts, numfreqs, load;
int ch, mode, mode_ac, mode_battery, mode_none;
uint64_t mjoules_used;
size_t len;
/* Default mode for all AC states is adaptive. */
mode_ac = mode_battery = mode_none = MODE_ADAPTIVE;
mode_ac = mode_none = MODE_HIADAPTIVE;
mode_battery = MODE_ADAPTIVE;
cpu_running_mark = DEFAULT_ACTIVE_PERCENT;
cpu_idle_mark = DEFAULT_IDLE_PERCENT;
poll_ival = DEFAULT_POLL_INTERVAL;
@ -418,7 +471,7 @@ main(int argc, char * argv[])
break;
case 'r':
cpu_running_mark = atoi(optarg);
if (cpu_running_mark < 0 || cpu_running_mark > 100) {
if (cpu_running_mark <= 0 || cpu_running_mark > 100) {
warnx("%d is not a valid percent",
cpu_running_mark);
usage();
@ -438,8 +491,8 @@ main(int argc, char * argv[])
/* Look up various sysctl MIBs. */
len = 2;
if (sysctlnametomib("kern.cp_time", cp_time_mib, &len))
err(1, "lookup kern.cp_time");
if (sysctlnametomib("kern.cp_times", cp_times_mib, &len))
err(1, "lookup kern.cp_times");
len = 4;
if (sysctlnametomib("dev.cpu.0.freq", freq_mib, &len))
err(1, "lookup freq");
@ -447,8 +500,8 @@ main(int argc, char * argv[])
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))
/* Check if we can read the load and supported freqs. */
if (read_usage_times(NULL))
err(1, "read_usage_times");
if (read_freqs(&numfreqs, &freqs, &mwatts))
err(1, "error reading supported CPU frequencies");
@ -483,6 +536,9 @@ main(int argc, char * argv[])
signal(SIGINT, handle_sigs);
signal(SIGTERM, handle_sigs);
freq = get_freq();
if (freq < 1)
freq = 1;
/* Main loop. */
for (;;) {
FD_ZERO(&fdset);
@ -522,37 +578,30 @@ main(int argc, char * argv[])
}
/* Read the current frequency. */
len = sizeof(curfreq);
if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0) != 0) {
if (vflag)
warn("error reading current CPU frequency");
if ((curfreq = get_freq()) == 0)
continue;
}
i = get_freq_id(curfreq, freqs, numfreqs);
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)
if (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]) {
freq = freqs[numfreqs - 1];
if (curfreq != freq) {
if (vflag) {
printf("now operating on %s power; "
"changing frequency to %d MHz\n",
modes[acline_status],
freqs[numfreqs - 1]);
modes[acline_status], freq);
}
if (set_freq(freqs[numfreqs - 1]) != 0) {
if (set_freq(freq) != 0) {
warn("error setting CPU freq %d",
freqs[numfreqs - 1]);
freq);
continue;
}
}
@ -561,16 +610,16 @@ main(int argc, char * argv[])
/* Always switch to the highest frequency in max mode. */
if (mode == MODE_MAX) {
if (curfreq != freqs[0]) {
freq = freqs[0];
if (curfreq != freq) {
if (vflag) {
printf("now operating on %s power; "
"changing frequency to %d MHz\n",
modes[acline_status],
freqs[0]);
modes[acline_status], freq);
}
if (set_freq(freqs[0]) != 0) {
if (set_freq(freq) != 0) {
warn("error setting CPU freq %d",
freqs[0]);
freq);
continue;
}
}
@ -578,44 +627,59 @@ main(int argc, char * argv[])
}
/* Adaptive mode; get the current CPU usage times. */
if (read_usage_times(&idle, &total)) {
if (read_usage_times(&load)) {
if (vflag)
warn("read_usage_times() failed");
continue;
}
/*
* If we're idle less than the active mark, bump up two levels.
* If we're idle more than the idle mark, drop down one level.
*/
for (i = 0; i < numfreqs - 1; i++) {
if (freqs[i] == curfreq)
break;
if (mode == MODE_ADAPTIVE) {
if (load > cpu_running_mark) {
if (load > 95 || load > cpu_running_mark * 2)
freq *= 2;
else
freq = freq * load / cpu_running_mark;
if (freq > freqs[0])
freq = freqs[0];
} else if (load < cpu_idle_mark &&
curfreq * load < freqs[get_freq_id(
freq * 7 / 8, freqs, numfreqs)] *
cpu_running_mark) {
freq = freq * 7 / 8;
if (freq < freqs[numfreqs - 1])
freq = freqs[numfreqs - 1];
}
} else { /* MODE_HIADAPTIVE */
if (load > cpu_running_mark / 2) {
if (load > 95 || load > cpu_running_mark)
freq *= 4;
else
freq = freq * load * 2 / cpu_running_mark;
if (freq > freqs[0] * 2)
freq = freqs[0] * 2;
} else if (load < cpu_idle_mark / 2 &&
curfreq * load < freqs[get_freq_id(
freq * 31 / 32, freqs, numfreqs)] *
cpu_running_mark / 2) {
freq = freq * 31 / 32;
if (freq < freqs[numfreqs - 1])
freq = freqs[numfreqs - 1];
}
}
if (idle < (total * cpu_running_mark) / 100 &&
curfreq < freqs[0]) {
i -= 2;
if (i < 0)
i = 0;
if (vflag) {
printf("load %3d%%, current freq %4d MHz (%2d), wanted freq %4d MHz\n",
load, curfreq, i, freq);
}
j = get_freq_id(freq, freqs, numfreqs);
if (i != j) {
if (vflag) {
printf("idle time < %d%%, increasing clock"
printf("changing clock"
" speed from %d MHz to %d MHz\n",
cpu_running_mark, curfreq, freqs[i]);
freqs[i], freqs[j]);
}
if (set_freq(freqs[i]))
if (set_freq(freqs[j]))
warn("error setting CPU frequency %d",
freqs[i]);
} else if (idle > (total * cpu_idle_mark) / 100 &&
curfreq > freqs[numfreqs - 1]) {
i++;
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]) != 0)
warn("error setting CPU frequency %d",
freqs[i]);
freqs[j]);
}
}
free(freqs);