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From: Richard Cochran <richardcochran@gmail.com>
To: Sebastien Laveze <sebastien.laveze@oss.nxp.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	yangbo.lu@nxp.com, yannick.vignon@oss.nxp.com,
	rui.sousa@oss.nxp.com
Subject: Re: [PATCH net-next] ptp: add vclock timestamp conversion IOCTL
Date: Thu, 7 Oct 2021 13:19:27 -0700	[thread overview]
Message-ID: <20211007201927.GA9326@hoboy.vegasvil.org> (raw)
In-Reply-To: <fea51ae9423c07e674402047851dd712ff1733bb.camel@oss.nxp.com>

On Thu, Oct 07, 2021 at 03:31:43PM +0200, Sebastien Laveze wrote:
> For example:
> Let's take a worst case, the PHC is adjusted every 10 ms, vclock every
> 1 sec with 1 ppm error.

You can't justify adjusting the HW clock and the vclocks
asynchronously with a single, isolated example.

If two independent processes are both adjusting a clock concurrently,
asynchronously, and at different control rates, the result will be
chaos.

It does not matter that it *might* work for some random setup of
yours.

The kernel has to function correctly in general, not just in some
special circumstances.

Thanks,
Richard


  reply	other threads:[~2021-10-07 20:19 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-27  9:32 Sebastien Laveze
2021-09-27 14:59 ` Richard Cochran
2021-09-27 16:00   ` Sebastien Laveze
2021-09-27 20:23     ` Richard Cochran
2021-09-28 11:50       ` Sebastien Laveze
2021-09-28 13:31         ` Richard Cochran
2021-09-29 15:00           ` Sebastien Laveze
2021-09-30 14:35             ` Richard Cochran
2021-10-07 13:31               ` Sebastien Laveze
2021-10-07 20:19                 ` Richard Cochran [this message]
2021-10-08  7:13                   ` Sebastien Laveze
2021-10-09 18:24                     ` Richard Cochran
2021-10-09 18:25                       ` Richard Cochran
2021-10-11 12:58                     ` Richard Cochran
2021-10-12 16:14                       ` Richard Cochran
2021-10-13  9:56                       ` Sebastien Laveze
2021-10-13 13:10                         ` Richard Cochran
2021-10-13 13:28                           ` Sebastien Laveze
2021-10-13 17:54                             ` Richard Cochran
2021-10-14 13:27                               ` Sebastien Laveze
2021-09-27 18:28 ` Randy Dunlap

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