Add temperature compensation
A new tempcomp directive can be used to specify a file for reading current temperature, update interval and compensation coefficients. The clock frequency corrections are applied in local module and are invisible in upper layers. The measurements and corrections can be logged to tempcomp.log file.
This commit is contained in:
Miroslav Lichvar
parent
f12bc10917
commit
c386d11765
10 changed files with 324 additions and 3 deletions
|
|
@ -46,7 +46,7 @@ OBJS = util.o sched.o regress.o local.o \
|
|||
nameserv.o acquire.o manual.o addrfilt.o \
|
||||
cmdparse.o mkdirpp.o rtc.o pktlength.o clientlog.o \
|
||||
broadcast.o refclock.o refclock_shm.o refclock_sock.o \
|
||||
refclock_pps.o
|
||||
refclock_pps.o tempcomp.o
|
||||
|
||||
EXTRA_OBJS=@EXTRA_OBJECTS@
|
||||
|
||||
|
|
|
|||
78
chrony.texi
78
chrony.texi
|
|
@ -1200,6 +1200,7 @@ directives can occur in any order in the file.
|
|||
* server directive:: Specify an NTP server
|
||||
* sched_priority directive:: Require real-time scheduling and specify a priority for it.
|
||||
* lock_all directive:: Require that chronyd be locked into RAM.
|
||||
* tempcomp directive:: Specify temperature sensor and compensation coefficients
|
||||
|
||||
@end menu
|
||||
@c }}}
|
||||
|
|
@ -1790,6 +1791,9 @@ This option logs information about the system's real-time clock.
|
|||
@item refclocks
|
||||
This option logs the raw and filtered reference clock measurements to
|
||||
a file called refclocks.log.
|
||||
@item tempcomp
|
||||
This option logs the temperature measurements and system rate
|
||||
compensations to a file called tempcomp.log.
|
||||
@end table
|
||||
|
||||
The files are written to the directory specified by the logdir
|
||||
|
|
@ -1807,6 +1811,7 @@ log measurements statistics tracking
|
|||
* tracking log:: The format of the tracking log
|
||||
* RTC log:: The format of the RTC log
|
||||
* refclocks log:: The format of the refclocks log
|
||||
* tempcomp log:: The format of the tempcomp log
|
||||
@end menu
|
||||
@c }}}
|
||||
@c {{{ measurements.log
|
||||
|
|
@ -2065,6 +2070,36 @@ that the local clock is slow. [-6.741777e-07]
|
|||
Assumed dispersion of the sample. [1.000e-06]
|
||||
@end enumerate
|
||||
|
||||
A banner is periodically written to the log file to indicate the
|
||||
meanings of the columns.
|
||||
@c }}}
|
||||
@c {{{ tempcomp.log
|
||||
@node tempcomp log
|
||||
@subsubsection Tempcomp log file format
|
||||
|
||||
An example line (which actually appears as a single line in the file)
|
||||
from the tempcomp log file is shown below.
|
||||
|
||||
@example
|
||||
2010-04-19 10:39:48 2.8000e+04 3.6600e-01
|
||||
@end example
|
||||
|
||||
The columns are as follows (the quantities in square brackets are the
|
||||
values from the example line above) :
|
||||
|
||||
@enumerate 1
|
||||
@item
|
||||
Date [2010-04-19]
|
||||
@item
|
||||
Hour:Minute:Second [10:39:48]. Note that the
|
||||
date/time pair is expressed in UTC, not the local time zone.
|
||||
@item
|
||||
Temperature read from tempcomp file. [2.8000e+04]
|
||||
@item
|
||||
Applied compensation in ppm, positive means the system clock is
|
||||
running faster than it would be without the compensation. [3.6600e-01]
|
||||
@end enumerate
|
||||
|
||||
A banner is periodically written to the log file to indicate the
|
||||
meanings of the columns.
|
||||
@c }}}
|
||||
|
|
@ -2563,6 +2598,49 @@ chronyc's @code{online} (@pxref{online command}) command when the link has been
|
|||
established, to enable measurements to start.)
|
||||
|
||||
@end table
|
||||
@c }}}
|
||||
@c {{{ tempcomp
|
||||
@node tempcomp directive
|
||||
@subsection tempcomp
|
||||
Normally, changes in rate of drift of the system clock are caused mainly by
|
||||
changes in temperature of the crystal oscillator on the mainboard.
|
||||
|
||||
If there are available temperature measurements from a sensor close to the
|
||||
oscillator, @code{tempcomp} directive can be used to compensate for the changes
|
||||
in rate and possibly improve clock accuracy.
|
||||
|
||||
Whether it will really help depends on many factors, including resolution of
|
||||
the sensor, noise in measurements, time source polling interval, compensation
|
||||
update interval, how good are the temperature coefficients, and how close is
|
||||
the sensor to the oscillator. The frequency reported in tracking.log should
|
||||
be more stable and the offsets should be smaller.
|
||||
|
||||
The directive has six parameters: path to the file which contains current
|
||||
temperature in text format, update interval (in seconds), and temperature
|
||||
coefficients T0, k0, k1, k2.
|
||||
|
||||
The frequency compensation is calculated (in ppm) as
|
||||
|
||||
@code{k0 + (T - T0) * k1 + (T - T0)^2 * k2}
|
||||
|
||||
The result has to be between -10 ppm and 10 ppm, otherwise the measurement is
|
||||
considered to be faulty and will be ignored. The k0 coefficient can be used to
|
||||
get the results in that range.
|
||||
|
||||
Valid measurements and calculated corrections are logged to tempcomp.log file if
|
||||
enabled with @code{log tempcomp} directive.
|
||||
|
||||
An example of use is
|
||||
|
||||
@example
|
||||
tempcomp /sys/class/hwmon/hwmon1/device/temp2_input 30 26000 0.0 0.000183 0.0
|
||||
@end example
|
||||
|
||||
The measured temperature will be read from the file in Linux sysfs filesystem
|
||||
every 30 seconds. When the temperature is 26 degress (26000), the system clock
|
||||
frequency will not be adjusted. When it is 27 degrees (27000), the clock will
|
||||
be set to run 0.183ppm faster than it would be without the compensation, etc.
|
||||
|
||||
@c }}}
|
||||
@c }}}
|
||||
@c {{{ S:Running chronyc
|
||||
|
|
|
|||
61
conf.c
61
conf.c
|
|
@ -105,6 +105,7 @@ static void parse_linux_hz(const char *);
|
|||
static void parse_linux_freq_scale(const char *);
|
||||
static void parse_sched_priority(const char *);
|
||||
static void parse_lockall(const char *);
|
||||
static void parse_tempcomp(const char *);
|
||||
|
||||
/* ================================================== */
|
||||
/* Configuration variables */
|
||||
|
|
@ -125,6 +126,7 @@ static int do_log_statistics = 0;
|
|||
static int do_log_tracking = 0;
|
||||
static int do_log_rtc = 0;
|
||||
static int do_log_refclocks = 0;
|
||||
static int do_log_tempcomp = 0;
|
||||
static int do_dump_on_exit = 0;
|
||||
static char *logdir = ".";
|
||||
static char *dumpdir = ".";
|
||||
|
|
@ -183,6 +185,11 @@ static IPAddr bind_cmd_address4, bind_cmd_address6;
|
|||
* chronyds being started. */
|
||||
static char *pidfile = "/var/run/chronyd.pid";
|
||||
|
||||
/* Temperature sensor, update interval and compensation coefficients */
|
||||
static char *tempcomp_file = NULL;
|
||||
static double tempcomp_interval;
|
||||
static double tempcomp_T0, tempcomp_k0, tempcomp_k1, tempcomp_k2;
|
||||
|
||||
/* Boolean for whether the Linux HZ value has been overridden, and the
|
||||
* new value. */
|
||||
static int set_linux_hz = 0;
|
||||
|
|
@ -239,6 +246,7 @@ static const Command commands[] = {
|
|||
{"rtcdevice", 9, parse_rtcdevice},
|
||||
{"pidfile", 7, parse_pidfile},
|
||||
{"broadcast", 9, parse_broadcast},
|
||||
{"tempcomp", 8, parse_tempcomp},
|
||||
{"linux_hz", 8, parse_linux_hz},
|
||||
{"linux_freq_scale", 16, parse_linux_freq_scale},
|
||||
{"sched_priority", 14, parse_sched_priority},
|
||||
|
|
@ -679,6 +687,9 @@ parse_log(const char *line)
|
|||
} else if (!strncmp(line, "refclocks", 9)) {
|
||||
do_log_refclocks = 1;
|
||||
line += 9;
|
||||
} else if (!strncmp(line, "tempcomp", 8)) {
|
||||
do_log_tempcomp = 1;
|
||||
line += 8;
|
||||
} else {
|
||||
break;
|
||||
}
|
||||
|
|
@ -1114,6 +1125,34 @@ parse_broadcast(const char *line)
|
|||
|
||||
/* ================================================== */
|
||||
|
||||
static void
|
||||
parse_tempcomp(const char *line)
|
||||
{
|
||||
const char *tmp;
|
||||
|
||||
while (isspace(line[0]))
|
||||
line++;
|
||||
tmp = line;
|
||||
while (line[0] != '\0' && !isspace(line[0]))
|
||||
line++;
|
||||
|
||||
if (line == tmp) {
|
||||
LOG(LOGS_WARN, LOGF_Configure, "Could not read tempcomp filename at line %d", line_number);
|
||||
return;
|
||||
}
|
||||
|
||||
if (sscanf(line, "%lf %lf %lf %lf %lf", &tempcomp_interval, &tempcomp_T0, &tempcomp_k0, &tempcomp_k1, &tempcomp_k2) != 5) {
|
||||
LOG(LOGS_WARN, LOGF_Configure, "Could not read tempcomp interval or coefficients at line %d", line_number);
|
||||
return;
|
||||
}
|
||||
|
||||
tempcomp_file = MallocArray(char, 1 + line - tmp);
|
||||
strncpy(tempcomp_file, tmp, line - tmp);
|
||||
tempcomp_file[line - tmp] = '\0';
|
||||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
||||
static void
|
||||
parse_linux_hz(const char *line)
|
||||
{
|
||||
|
|
@ -1273,6 +1312,7 @@ CNF_GetLogRtc(void)
|
|||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
||||
int
|
||||
CNF_GetLogRefclocks(void)
|
||||
{
|
||||
|
|
@ -1281,6 +1321,14 @@ CNF_GetLogRefclocks(void)
|
|||
|
||||
/* ================================================== */
|
||||
|
||||
int
|
||||
CNF_GetLogTempComp(void)
|
||||
{
|
||||
return do_log_tempcomp;
|
||||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
||||
char *
|
||||
CNF_GetKeysFile(void)
|
||||
{
|
||||
|
|
@ -1514,3 +1562,16 @@ CNF_GetLockMemory(void)
|
|||
{
|
||||
return lock_memory;
|
||||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
||||
void
|
||||
CNF_GetTempComp(char **file, double *interval, double *T0, double *k0, double *k1, double *k2)
|
||||
{
|
||||
*file = tempcomp_file;
|
||||
*interval = tempcomp_interval;
|
||||
*T0 = tempcomp_T0;
|
||||
*k0 = tempcomp_k0;
|
||||
*k1 = tempcomp_k1;
|
||||
*k2 = tempcomp_k2;
|
||||
}
|
||||
|
|
|
|||
3
conf.h
3
conf.h
|
|
@ -53,6 +53,7 @@ extern int CNF_GetLogStatistics(void);
|
|||
extern int CNF_GetLogTracking(void);
|
||||
extern int CNF_GetLogRtc(void);
|
||||
extern int CNF_GetLogRefclocks(void);
|
||||
extern int CNF_GetLogTempComp(void);
|
||||
extern char *CNF_GetKeysFile(void);
|
||||
extern char *CNF_GetRtcFile(void);
|
||||
extern unsigned long CNF_GetCommandKey(void);
|
||||
|
|
@ -81,4 +82,6 @@ extern void CNF_SetupAccessRestrictions(void);
|
|||
extern int CNF_GetSchedPriority(void);
|
||||
extern int CNF_GetLockMemory(void);
|
||||
|
||||
extern void CNF_GetTempComp(char **file, double *interval, double *T0, double *k0, double *k1, double *k2);
|
||||
|
||||
#endif /* GOT_CONF_H */
|
||||
|
|
|
|||
43
local.c
43
local.c
|
|
@ -45,6 +45,9 @@
|
|||
/* Variable to store the current frequency, in ppm */
|
||||
static double current_freq_ppm;
|
||||
|
||||
/* Temperature compensation, in ppm */
|
||||
static double temp_comp_ppm;
|
||||
|
||||
/* ================================================== */
|
||||
/* Store the system dependent drivers */
|
||||
|
||||
|
|
@ -152,6 +155,7 @@ LCL_Initialise(void)
|
|||
|
||||
/* This ought to be set from the system driver layer */
|
||||
current_freq_ppm = 0.0;
|
||||
temp_comp_ppm = 0.0;
|
||||
|
||||
calculate_sys_precision();
|
||||
}
|
||||
|
|
@ -360,7 +364,16 @@ LCL_GetOffsetCorrection(struct timeval *raw, double *correction, double *err)
|
|||
double
|
||||
LCL_ReadAbsoluteFrequency(void)
|
||||
{
|
||||
return (*drv_read_freq)();
|
||||
double freq;
|
||||
|
||||
freq = (*drv_read_freq)();
|
||||
|
||||
/* Undo temperature compensation */
|
||||
if (temp_comp_ppm != 0.0) {
|
||||
freq = (freq + temp_comp_ppm) / (1.0 - 1.0e-6 * temp_comp_ppm);
|
||||
}
|
||||
|
||||
return freq;
|
||||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
|
@ -374,6 +387,11 @@ LCL_SetAbsoluteFrequency(double afreq_ppm)
|
|||
struct timeval raw, cooked;
|
||||
double dfreq;
|
||||
|
||||
/* Apply temperature compensation */
|
||||
if (temp_comp_ppm != 0.0) {
|
||||
afreq_ppm = afreq_ppm * (1.0 - 1.0e-6 * temp_comp_ppm) - temp_comp_ppm;
|
||||
}
|
||||
|
||||
/* Call the system-specific driver for setting the frequency */
|
||||
|
||||
(*drv_set_freq)(afreq_ppm);
|
||||
|
|
@ -580,3 +598,26 @@ LCL_SetLeap(int leap)
|
|||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
||||
void
|
||||
LCL_SetTempComp(double comp)
|
||||
{
|
||||
if (temp_comp_ppm == comp)
|
||||
return;
|
||||
|
||||
/* Undo previous compensation */
|
||||
current_freq_ppm = (current_freq_ppm + temp_comp_ppm) /
|
||||
(1.0 - 1.0e-6 * temp_comp_ppm);
|
||||
|
||||
/* Apply new compensation */
|
||||
current_freq_ppm = current_freq_ppm * (1.0 - 1.0e-6 * comp) - comp;
|
||||
|
||||
temp_comp_ppm = comp;
|
||||
|
||||
/* Call the system-specific driver for setting the frequency */
|
||||
(*drv_set_freq)(current_freq_ppm);
|
||||
|
||||
return;
|
||||
}
|
||||
|
||||
/* ================================================== */
|
||||
|
|
|
|||
5
local.h
5
local.h
|
|
@ -188,4 +188,9 @@ extern int LCL_MakeStep(double threshold);
|
|||
and zero cancels scheduled leap second. */
|
||||
extern void LCL_SetLeap(int leap);
|
||||
|
||||
/* Routine to set a frequency correction (in ppm) that should be applied
|
||||
to local clock to compensate for temperature changes. A positive
|
||||
argument means that the clock frequency should be increased. */
|
||||
extern void LCL_SetTempComp(double comp);
|
||||
|
||||
#endif /* GOT_LOCAL_H */
|
||||
|
|
|
|||
|
|
@ -58,7 +58,7 @@ struct LogFile {
|
|||
static int n_filelogs = 0;
|
||||
|
||||
/* Increase this when adding a new logfile */
|
||||
#define MAX_FILELOGS 5
|
||||
#define MAX_FILELOGS 6
|
||||
|
||||
static struct LogFile logfiles[MAX_FILELOGS];
|
||||
|
||||
|
|
|
|||
3
main.c
3
main.c
|
|
@ -53,6 +53,7 @@
|
|||
#include "clientlog.h"
|
||||
#include "broadcast.h"
|
||||
#include "nameserv.h"
|
||||
#include "tempcomp.h"
|
||||
|
||||
/* ================================================== */
|
||||
|
||||
|
|
@ -86,6 +87,7 @@ MAI_CleanupAndExit(void)
|
|||
SRC_DumpSources();
|
||||
}
|
||||
|
||||
TMC_Finalise();
|
||||
MNL_Finalise();
|
||||
ACQ_Finalise();
|
||||
KEY_Finalise();
|
||||
|
|
@ -326,6 +328,7 @@ int main
|
|||
KEY_Initialise();
|
||||
ACQ_Initialise();
|
||||
MNL_Initialise();
|
||||
TMC_Initialise();
|
||||
|
||||
LOG_CreateLogFileDir();
|
||||
|
||||
|
|
|
|||
101
tempcomp.c
Normal file
101
tempcomp.c
Normal file
|
|
@ -0,0 +1,101 @@
|
|||
/*
|
||||
chronyd/chronyc - Programs for keeping computer clocks accurate.
|
||||
|
||||
**********************************************************************
|
||||
* Copyright (C) Miroslav Lichvar 2010
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of version 2 of the GNU General Public License as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful, but
|
||||
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License along
|
||||
* with this program; if not, write to the Free Software Foundation, Inc.,
|
||||
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||||
*
|
||||
**********************************************************************
|
||||
|
||||
=======================================================================
|
||||
|
||||
Routines implementing temperature compensation.
|
||||
|
||||
*/
|
||||
|
||||
#include "conf.h"
|
||||
#include "local.h"
|
||||
#include "memory.h"
|
||||
#include "util.h"
|
||||
#include "logging.h"
|
||||
#include "sched.h"
|
||||
#include "tempcomp.h"
|
||||
|
||||
static SCH_TimeoutID timeout_id;
|
||||
|
||||
static LOG_FileID logfileid;
|
||||
|
||||
static char *filename;
|
||||
static double update_interval;
|
||||
static double T0, k0, k1, k2;
|
||||
|
||||
static void
|
||||
read_timeout(void *arg)
|
||||
{
|
||||
FILE *f;
|
||||
double temp, comp;
|
||||
|
||||
f = fopen(filename, "r");
|
||||
|
||||
if (f && fscanf(f, "%lf", &temp) == 1) {
|
||||
comp = k0 + (temp - T0) * k1 + (temp - T0) * (temp - T0) * k2;
|
||||
|
||||
/* Don't allow corrections above 10 ppm */
|
||||
if (fabs(comp) < 10.0) {
|
||||
LCL_SetTempComp(comp);
|
||||
|
||||
if (logfileid != -1) {
|
||||
struct timeval now;
|
||||
|
||||
LCL_ReadCookedTime(&now, NULL);
|
||||
LOG_FileWrite(logfileid, "%s %11.4e %11.4e",
|
||||
UTI_TimeToLogForm(now.tv_sec), temp, comp);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (f)
|
||||
fclose(f);
|
||||
|
||||
timeout_id = SCH_AddTimeoutByDelay(update_interval, read_timeout, NULL);
|
||||
}
|
||||
|
||||
void
|
||||
TMC_Initialise(void)
|
||||
{
|
||||
CNF_GetTempComp(&filename, &update_interval, &T0, &k0, &k1, &k2);
|
||||
|
||||
if (filename == NULL)
|
||||
return;
|
||||
|
||||
if (update_interval <= 0.0)
|
||||
update_interval = 1.0;
|
||||
|
||||
logfileid = CNF_GetLogTempComp() ? LOG_FileOpen("tempcomp",
|
||||
" Date (UTC) Time Temp. Comp.")
|
||||
: -1;
|
||||
|
||||
read_timeout(NULL);
|
||||
}
|
||||
|
||||
void
|
||||
TMC_Finalise(void)
|
||||
{
|
||||
if (filename == NULL)
|
||||
return;
|
||||
|
||||
SCH_RemoveTimeout(timeout_id);
|
||||
Free(filename);
|
||||
}
|
||||
29
tempcomp.h
Normal file
29
tempcomp.h
Normal file
|
|
@ -0,0 +1,29 @@
|
|||
/*
|
||||
chronyd/chronyc - Programs for keeping computer clocks accurate.
|
||||
|
||||
**********************************************************************
|
||||
* Copyright (C) Miroslav Lichvar 2010
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of version 2 of the GNU General Public License as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful, but
|
||||
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License along
|
||||
* with this program; if not, write to the Free Software Foundation, Inc.,
|
||||
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||||
*
|
||||
**********************************************************************
|
||||
|
||||
=======================================================================
|
||||
|
||||
Header file for temperature compensation.
|
||||
|
||||
*/
|
||||
|
||||
extern void TMC_Initialise(void);
|
||||
extern void TMC_Finalise(void);
|
||||
Loading…
Reference in a new issue