From: Miroslav Lichvar <mlichvar@redhat.com>
To: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Cc: netdev@vger.kernel.org, john.stultz@linaro.org,
Richard Cochran <rcochran@linutronix.de>,
jiri@resnulli.us, ivan.briano@intel.com,
richardcochran@gmail.com, henrik@austad.us, jhs@mojatatu.com,
levi.pearson@harman.com, intel-wired-lan@lists.osuosl.org,
xiyou.wangcong@gmail.com, tglx@linutronix.de,
anna-maria@linutronix.de
Subject: Re: [Intel-wired-lan] [RFC v2 net-next 01/10] net: Add a new socket option for a future transmit time.
Date: Tue, 13 Feb 2018 10:56:52 +0100 [thread overview]
Message-ID: <20180213095652.GA11459@localhost> (raw)
In-Reply-To: <d30c45f7-0091-3701-4ffe-3bc712f6436b@intel.com>
On Mon, Feb 12, 2018 at 02:39:06PM -0800, Jesus Sanchez-Palencia wrote:
> On 01/18/2018 12:42 AM, Miroslav Lichvar wrote:
> > Please keep in mind that the PHCs and the system clock don't have to
> > be synchronized to each other. If I understand the rest of the series
> > correctly, there is an assumption that the PHCs are keeping time in
> > TAI and CLOCK_TAI can be used as a fallback.
>
> Just to double-check, imagine that I've configured the qdisc for
> SW best-effort and with clockid CLOCK_REALTIME. When it receives a
> packet with the clockid of a /dev/ptpX, the qdisc should just drop that
> packet, right?
Yes, I think it should drop it. The kernel does not know the offset
between the two clocks (they don't even have to be synchronized), so
it cannot convert a PHC-based TX time to the system time.
--
Miroslav Lichvar
next prev parent reply other threads:[~2018-02-13 9:56 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-17 23:06 [RFC v2 net-next 00/10] Time based packet transmission Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 01/10] net: Add a new socket option for a future transmit time Jesus Sanchez-Palencia
2018-01-18 8:42 ` [Intel-wired-lan] " Miroslav Lichvar
2018-01-18 17:13 ` Richard Cochran
2018-02-01 0:49 ` Jesus Sanchez-Palencia
2018-02-01 4:16 ` Richard Cochran
2018-02-01 9:27 ` Miroslav Lichvar
2018-02-01 20:55 ` Jesus Sanchez-Palencia
2018-01-23 21:22 ` Vinicius Costa Gomes
2018-01-24 3:04 ` Richard Cochran
2018-01-24 22:46 ` Vinicius Costa Gomes
2018-01-26 2:12 ` Richard Cochran
2018-02-12 22:39 ` Jesus Sanchez-Palencia
2018-02-13 9:56 ` Miroslav Lichvar [this message]
2018-01-18 17:11 ` Richard Cochran
2018-01-23 18:12 ` Jesus Sanchez-Palencia
2018-01-19 21:15 ` Willem de Bruijn
2018-01-20 2:09 ` Richard Cochran
2018-01-25 9:12 ` [Intel-wired-lan] " Miroslav Lichvar
2018-01-25 16:52 ` Richard Cochran
2018-01-23 18:24 ` Jesus Sanchez-Palencia
2018-01-23 20:02 ` Willem de Bruijn
2018-01-17 23:06 ` [RFC v2 net-next 02/10] net: ipv4: raw: Hook into time based transmission Jesus Sanchez-Palencia
2018-01-18 0:28 ` Eric Dumazet
2018-01-17 23:06 ` [RFC v2 net-next 03/10] net: ipv4: udp: " Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 04/10] net: packet: " Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 05/10] net/sched: Allow creating a Qdisc watchdog with other clocks Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 06/10] net/sched: Introduce the TBS Qdisc Jesus Sanchez-Palencia
2018-01-18 13:35 ` Jamal Hadi Salim
2018-01-18 13:44 ` Jamal Hadi Salim
2018-01-23 21:45 ` Jesus Sanchez-Palencia
2018-01-18 17:18 ` Richard Cochran
2018-01-23 22:01 ` Jesus Sanchez-Palencia
2018-01-19 21:18 ` Willem de Bruijn
2018-01-17 23:06 ` [RFC v2 net-next 07/10] igb: Refactor igb_configure_cbs() Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 08/10] igb: Only change Tx arbitration when CBS is on Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 09/10] igb: Refactor igb_offload_cbs() Jesus Sanchez-Palencia
2018-01-17 23:06 ` [RFC v2 net-next 10/10] igb: Add support for TBS offload Jesus Sanchez-Palencia
2018-01-23 5:23 ` [RFC v2 net-next 00/10] Time based packet transmission Richard Cochran
2018-01-23 5:26 ` Richard Cochran
2018-01-23 18:07 ` Jesus Sanchez-Palencia
2018-01-24 1:43 ` Levi Pearson
2018-01-27 0:04 ` Jesus Sanchez-Palencia
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