Le 28/11/2014 22:00, Richard Cochran a écrit : > On Fri, Nov 28, 2014 at 02:40:44PM +0100, Laurent Georget wrote: >> @@ -101,7 +99,19 @@ combination of zero or more of the following bits: >> Ordinary users are restricted to a zero value for >> .IR modes . >> Only the superuser may set any parameters. >> +.PP >> +Support for TAI (Atomic International Time, for a complete explanation >> about >> +what it is and what is the difference between TAI and UTC, see >> +.UR http://www.bipm.org/en/bipm/tai/tai.html >> +.I BIPM >> +.UE ) >> +has been added in version 2.6.29. For any clock, the TAI offset may > > Not for "any clock", just for CLOCK_REALTIME. Considering that this is the only one representing the "human" time and supporting an adjtime action, indeed, it's not relevant for anything else than the realtime clock. > >> +be calculated by adding a value to the UTC offset which is updated when a >> +leap second is added or deleted. >> .br >> +All the offsets in the timex structure are expressed between the value >> of the >> +clock and the corresponding value (e.g. TAI offset is the difference >> between >> +the clock and the TAI, not between TAI and another value such as UTC). > > The TAI offset is just (TAI - UTC). That's all. > Yes, my mistake, I misunderstood the part about timekeeping (__timekeeping_set_tai_offset() in kernel/time/timekeeping.c, line 815) which does store the offset in several formats (monotonic -> TAI and UTC -> TAI). But this is not directly related to the timex value. Aniway this is not very relevant in the man page. Thank you for your comments. Below is a new version of the patch. Less unrelevant chit-chat, more useful information (hopefully). diff --git a/man2/adjtimex.2 b/man2/adjtimex.2 index 20a2f0b..871e607 100644 --- a/man2/adjtimex.2 +++ b/man2/adjtimex.2 @@ -26,9 +26,6 @@ .\" Modified 2004-05-27 by Michael Kerrisk <mtk.manpages@xxxxxxxxx> .\" Modified 2014-11-28 by Laurent Georget <laurent.georget@xxxxxxxxxx> .\" -.\" FIXME Document ADJ_TAI (added in Linux 2.6.26) -.\" commit 153b5d054ac2d98ea0d86504884326b6777f683d -.\" .\" FIXME Document ADJ_MICRO and ADJ_NANO (added in Linux 2.6.26) .\" commit eea83d896e318bda54be2d2770d2c5d6668d11db .\" Author: Roman Zippel <zippel@xxxxxxxxxxxxxx> @@ -74,6 +71,17 @@ struct timex { (read-only) */ struct timeval time; /* current time (read-only) */ long tick; /* usecs between clock ticks */ + + long ppsfreq; /* pps frequency (scaled ppm) (read-only) */ + long jitter; /* pps jitter (usec) (read-only) */ + int shift; /* interval duration (sec) (read-only) */ + long stabil; /* pps stability (scaled ppm) (read-only) */ + long jitcnt; /* jitter limit exceeded (read-only) */ + long calcnt; /* calibration intervals (read-only) */ + long errcnt; /* calibration errors (read-only) */ + long stbcnt; /* stability limit exceeded (read-only) */ + + int tai; /* TAI offset (s) (read-only) */ }; .fi .in @@ -93,6 +101,7 @@ combination of zero or more of the following bits: #define ADJ_ESTERROR 0x0008 /* estimated time error */ #define ADJ_STATUS 0x0010 /* clock status */ #define ADJ_TIMECONST 0x0020 /* pll time constant */ +#define ADJ_TAI 0x0080 /* TAI offset */ #define ADJ_TICK 0x4000 /* tick value */ #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime() */ .fi @@ -102,6 +111,20 @@ Ordinary users are restricted to a zero value for .IR modes . Only the superuser may set any parameters. .br +In the case of +.BR ADJ_TAI , +as +.I buf->tai +is read-only, the new value is passed through +.IR buf->constant . +.PP +Support for TAI (Atomic International Time, for a complete explanation about +what it is and what is the difference between TAI and UTC, see +.UR http://www.bipm.org/en/bipm/tai/tai.html +.I BIPM +.UE ) +has been added in version 2.6.29. +.br .ne 12v .SH RETURN VALUE On success, -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
