From: john stultz <johnstul@us.ibm.com>
To: "Kuwahara,T." <6vvetjsrt26xsrzlh1z0zn4d2grdah@gmail.com>
Cc: Richard Cochran <richardcochran@gmail.com>,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
netdev@vger.kernel.org, Alan Cox <alan@lxorguk.ukuu.org.uk>,
Arnd Bergmann <arnd@arndb.de>, Christoph Lameter <cl@linux.com>,
David Miller <davem@davemloft.net>,
Krzysztof Halasa <khc@pm.waw.pl>,
Peter Zijlstra <peterz@infradead.org>,
Rodolfo Giometti <giometti@linux.it>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH V8 02/13] ntp: add ADJ_SETOFFSET mode bit
Date: Mon, 10 Jan 2011 08:49:05 -0800 [thread overview]
Message-ID: <1294678145.3068.6.camel@work-vm> (raw)
In-Reply-To: <AANLkTikigXGSACF6R6kfNHyKZ7GFWrUrCMxygvL3fUC6@mail.gmail.com>
On Mon, 2011-01-10 at 06:07 +0900, Kuwahara,T. wrote:
> On Sun, Jan 9, 2011 at 2:50 AM, Richard Cochran
> <richardcochran@gmail.com> wrote:
> > we want to be able to jump the clock arbitrarily.
>
> Another problem remains: How do you deal with leap seconds? I mean,
> given that 1 minute is not always 60 seconds, then what time was it
> XXXXX seconds ago? Maybe some kind of lookup table is necessary, but
> in such case, isn't it a better choice just to use the
> clock_settime/settimeofday syscall?
Leapsecond processing is done via an absolute hrtimer. Thus when the
time offset is set, the hrtimers that should have expired will fire
(just like with settimeofday) and the adjustment will then be made.
thanks
-john
next prev parent reply other threads:[~2011-01-10 16:49 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-31 19:11 [PATCH V8 00/13] ptp: IEEE 1588 hardware clock support Richard Cochran
2010-12-31 19:12 ` [PATCH V8 01/13] time: Introduce timekeeping_inject_offset John Stultz
2011-01-06 22:00 ` Arnd Bergmann
2010-12-31 19:12 ` [PATCH V8 02/13] ntp: add ADJ_SETOFFSET mode bit Richard Cochran
2011-01-01 20:38 ` Kuwahara,T.
2011-01-08 17:50 ` Richard Cochran
2011-01-09 21:07 ` Kuwahara,T.
2011-01-10 7:17 ` Richard Cochran
2011-01-10 20:47 ` Kuwahara,T.
2011-01-10 21:11 ` john stultz
2011-01-11 11:09 ` Richard Cochran
2011-01-10 7:22 ` Richard Cochran
2011-01-10 16:49 ` john stultz [this message]
2011-01-10 20:45 ` Kuwahara,T.
2011-01-10 21:06 ` john stultz
2011-01-11 20:32 ` Kuwahara,T.
2011-01-11 20:55 ` john stultz
2011-01-12 20:39 ` Kuwahara,T.
2011-01-12 20:55 ` john stultz
2010-12-31 19:13 ` [PATCH V8 03/13] posix clocks: introduce a syscall for clock tuning Richard Cochran
2010-12-31 19:13 ` [PATCH V8 04/13] posix_clocks: add clock_adjtime for arm Richard Cochran
2010-12-31 19:14 ` [PATCH V8 05/13] posix_clocks: add clock_adjtime for blackfin Richard Cochran
2010-12-31 19:14 ` [PATCH V8 06/13] posix_clocks: add clock_adjtime for powerpc Richard Cochran
2010-12-31 19:14 ` [PATCH V8 07/13] posix_clocks: add clock_adjtime for x86 Richard Cochran
2010-12-31 19:15 ` [PATCH V8 08/13] posix clocks: cleanup the CLOCK_DISPTACH macro Richard Cochran
2011-01-03 9:29 ` Peter Zijlstra
2011-01-03 11:51 ` Richard Cochran
2011-01-11 12:57 ` Thomas Gleixner
2011-01-12 7:37 ` Richard Cochran
2011-01-12 11:16 ` Thomas Gleixner
2011-01-12 12:17 ` Richard Cochran
2011-01-13 4:30 ` Richard Cochran
2011-01-13 11:25 ` Thomas Gleixner
2010-12-31 19:15 ` [PATCH V8 09/13] posix clocks: introduce dynamic clocks Richard Cochran
2011-01-06 19:56 ` Arnd Bergmann
2011-01-07 16:41 ` Richard Cochran
2010-12-31 19:16 ` [PATCH V8 10/13] ptp: Added a brand new class driver for ptp clocks Richard Cochran
2010-12-31 19:16 ` [PATCH V8 11/13] ptp: Added a clock that uses the eTSEC found on the MPC85xx Richard Cochran
2010-12-31 19:17 ` [PATCH V8 12/13] ptp: Added a clock driver for the IXP46x Richard Cochran
2011-01-06 21:01 ` Krzysztof Halasa
2011-01-07 17:07 ` Richard Cochran
2011-01-08 16:25 ` Krzysztof Halasa
2011-01-10 20:24 ` Krzysztof Halasa
2010-12-31 19:17 ` [PATCH V8 13/13] ptp: Added a clock driver for the National Semiconductor PHYTER Richard Cochran
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