From: Miroslav Lichvar <mlichvar@redhat.com>
To: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: John Stultz <jstultz@google.com>,
Frederic Weisbecker <frederic@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
Richard Cochran <richardcochran@gmail.com>,
Christopher S Hall <christopher.s.hall@intel.com>
Subject: Re: [PATCH 00/21] ntp: Rework to prepare support of indenpendent PTP clocks
Date: Thu, 12 Sep 2024 10:12:59 +0200 [thread overview]
Message-ID: <ZuKii1KDGHSXElB6@localhost> (raw)
In-Reply-To: <20240911-devel-anna-maria-b4-timers-ptp-ntp-v1-0-2d52f4e13476@linutronix.de>
On Wed, Sep 11, 2024 at 03:17:36PM +0200, Anna-Maria Behnsen wrote:
> This problem can be solved by emulating clock_gettime() via the system
> clock source e.g. TSC on x86. Such emulation requires:
>
> 1. timekeeping mechanism similar to the existing system timekeeping
> 2. clock steering equivalent to NTP/adjtimex()
I'm trying to understand what independent PTP clocks means here. Is
the goal to provide virtual PTP clocks running on top of the system
clocksource (e.g. TSC) similarly to what is currently done for
physical PTP clocks by writing to /sys/class/ptp/ptp*/n_vclocks,
expecting the virtual clocks to be synchronized by applications like
phc2sys?
Or is this more about speeding up the reading of the PHC, where the
kernel itself would be tracking the offset using one of the PTP
driver's PTP_SYS_OFFSET operations and emulating a fast-reading PHC?
--
Miroslav Lichvar
next prev parent reply other threads:[~2024-09-12 8:13 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-11 13:17 [PATCH 00/21] ntp: Rework to prepare support of indenpendent PTP clocks Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 01/21] ntp: Remove unused tick_nsec Anna-Maria Behnsen
2024-09-11 20:06 ` John Stultz
2024-09-11 13:17 ` [PATCH 02/21] ntp: Make tick_usec static Anna-Maria Behnsen
2024-09-11 20:28 ` John Stultz
2024-09-11 13:17 ` [PATCH 03/21] ntp: Clean up comments Anna-Maria Behnsen
2024-09-11 20:08 ` John Stultz
2024-09-11 13:17 ` [PATCH 04/21] ntp: Cleanup formatting of code Anna-Maria Behnsen
2024-09-11 20:11 ` John Stultz
2024-09-11 13:17 ` [PATCH 05/21] ntp: Convert functions with only two states to bool Anna-Maria Behnsen
2024-09-11 20:12 ` John Stultz
2024-09-11 13:17 ` [PATCH 06/21] ntp: Read reference time only once Anna-Maria Behnsen
2024-09-11 20:00 ` John Stultz
2024-09-11 13:17 ` [PATCH 07/21] ntp: Introduce struct ntp_data Anna-Maria Behnsen
2024-09-11 20:20 ` John Stultz
2024-09-11 13:17 ` [PATCH 08/21] ntp: Move tick_length* into ntp_data Anna-Maria Behnsen
2024-09-11 20:23 ` John Stultz
2024-09-11 13:17 ` [PATCH 09/21] ntp: Move tick_stat* " Anna-Maria Behnsen
2024-09-11 20:25 ` John Stultz
2024-09-11 13:17 ` [PATCH 10/21] ntp: Move time_offset/constant " Anna-Maria Behnsen
2024-09-11 20:27 ` John Stultz
2024-09-11 13:17 ` [PATCH 11/21] ntp: Move time_max/esterror " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 12/21] ntp: Move time_freq/reftime " Anna-Maria Behnsen
2024-09-11 20:30 ` John Stultz
2024-09-11 13:17 ` [PATCH 13/21] ntp: Move time_adj/ntp_tick_adj " Anna-Maria Behnsen
2024-09-11 20:36 ` John Stultz
2024-09-11 13:17 ` [PATCH 14/21] ntp: Move ntp_next_leap_sec " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 15/21] ntp: Move pps_valid " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 16/21] ntp: Move pps_ft " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 17/21] ntp: Move pps_jitter " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 18/21] ntp: Move pps_fbase " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 19/21] ntp: Move pps_shift/intcnt " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 20/21] ntp: Move pps_freq/stabil " Anna-Maria Behnsen
2024-09-11 13:17 ` [PATCH 21/21] ntp: Move pps monitors " Anna-Maria Behnsen
2024-09-12 8:12 ` Miroslav Lichvar [this message]
2024-09-13 3:59 ` [PATCH 00/21] ntp: Rework to prepare support of indenpendent PTP clocks Richard Cochran
2024-09-13 10:28 ` Anna-Maria Behnsen
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