Date: Thu, 12 Aug 2010 17:17:05 +0000 (UTC) From: Jung-uk Kim <jkim@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/kern subr_rtc.c Message-ID: <201008121717.o7CHHIZK082505@repoman.freebsd.org>
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jkim 2010-08-12 17:17:05 UTC
FreeBSD src repository
Modified files:
sys/kern subr_rtc.c
Log:
SVN rev 211230 on 2010-08-12 17:17:05Z by jkim
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.
Revision Changes Path
1.14 +7 -1 src/sys/kern/subr_rtc.c
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