Commit Graph

14 Commits

Author SHA1 Message Date
Jung-uk Kim
116a77bda7 Add the half of time-of-day clock resolution when we adjust system time from
time-of-day clock or vice versa.  For x86 systems, RTC resolution is one
second and we used to lose up to one second whenever we initialize system
time from RTC or write system time back to RTC.  With this change, margin
of error per conversion is roughly between -0.5 and +0.5 second rather
than between -1 and 0 second.  Note that it does not take care of errors
from getnanotime(9) (which is up to 1/hz second) or CLOCK_GETTIME() latency.
These are just too expensive to correct and it is not worthy of the cost.
2010-08-12 17:17:05 +00:00
Jung-uk Kim
0674ea6f69 Provide description for 'machdep.disable_rtc_set' sysctl. Clean up style(9)
nits.  Remove a redundant return statement and an unnecessary variable.
2010-08-12 16:13:24 +00:00
Jung-uk Kim
eae44ae03d Clean up MI inittodr(9) and kill noop code.
It was derived from i386 version long ago but never resync'ed again.
Originally, i386 version compared the current time from realtime clock
with time_second (which was just `time' in the old days).  When this MI
version was written, it was wrongly compared against `base' AND never
used because of a bug (typo?) in the code.  This check was killed
in i386 version when home-rolled calendaric calculation was removed.
Now, we just remove the code here as well to make the code simpler.
2009-03-23 21:16:21 +00:00
Warner Losh
9483543dfc int foo(void) is the proper ANSI function definition when there's no
parameters.  Use it for resettodr().
2009-02-03 07:50:01 +00:00
Poul-Henning Kamp
9b4a8ab7ba Now that all platforms use genclock, shuffle things around slightly
for better structure.

Much of this is related to <sys/clock.h>, which should really have
been called <sys/calendar.h>, but unless and until we need the name,
the repocopy can wait.

In general the kernel does not know about minutes, hours, days,
timezones, daylight savings time, leap-years and such.  All that
is theoretically a matter for userland only.

Parts of kernel code does however care: badly designed filesystems
store timestamps in local time and RTC chips almost universally
track time in a YY-MM-DD HH:MM:SS format, and sometimes in local
timezone instead of UTC.  For this we have <sys/clock.h>

<sys/time.h> on the other hand, deals with time_t, timeval, timespec
and so on.  These know only seconds and fractions thereof.

Move inittodr() and resettodr() prototypes to <sys/time.h>.
Retain the names as it is one of the few surviving PDP/VAX references.

Move startrtclock() to <machine/clock.h> on relevant platforms, it
is a MD call between machdep.c/clock.c.  Remove references to it
elsewhere.

Remove a lot of unnecessary <sys/clock.h> includes.

Move the machdep.disable_rtc_set sysctl to subr_rtc.c where it belongs.
XXX: should be kern.disable_rtc_set really, it's not MD.
2008-04-22 19:38:30 +00:00
Poul-Henning Kamp
e5037a18a9 Use utc_offset() where applicable, and hide the internals of it
as static variables.
2006-10-02 18:23:37 +00:00
Poul-Henning Kamp
b69f71eb29 Second part of a little cleanup in the calendar/timezone/RTC handling.
Split subr_clock.c in two parts (by repo-copy):
   subr_clock.c contains generic RTC and calendaric stuff. etc.
   subr_rtc.c contains the newbus'ified RTC interface.

Centralize the machdep.{adjkerntz,disable_rtc_set,wall_cmos_clock}
sysctls and associated variables into subr_clock.c.  They are
not machine dependent and we have generic code that relies on being
present so they are not even optional.
2006-10-02 15:42:02 +00:00
Poul-Henning Kamp
99ab8292c7 Remove more straggling CPU_ macro references 2006-05-11 17:53:26 +00:00
Warner Losh
9454b2d864 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
Warner Losh
7f8a436ff2 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-05 21:03:37 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Poul-Henning Kamp
91f1c2b3cc Split the global timezone structure into two integer fields to
prevent the compiler from optimizing assignments into byte-copy
operations which might make access to the individual fields non-atomic.

Use the individual fields throughout, and don't bother locking them with
Giant: it is no longer needed.

Inspired by:    tjr
2003-02-03 19:49:35 +00:00
Thomas Moestl
d88d37d604 Use the CPU_* OID constants instead of OID_AUTO for the clock-related
sysctls for compatability with old applications.
2002-08-07 19:43:54 +00:00
Thomas Moestl
d7f7792edf Add a generic implementation of inittodr() and resettodr(), as well as
a set of helper routines to deal with real-time clocks. The generic
functions access the clock diver using a kobj interface. This is intended
to reduce code reduplication and make it easy to support more than one
clock model on a single architecture.

This code is currently only used on sparc64, but it is planned to convert
the code of the other architectures to it later.
2002-04-04 23:39:10 +00:00