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Date: Sat, 16 Jul 2022 11:55:41 -0700
From: Gleb Smirnoff <glebius@freebsd.org>
To: Konstantin Belousov <kostikbel@gmail.com>
Cc: Dmitry Chagin <dchagin@freebsd.org>, src-committers@freebsd.org,
        dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org
Subject: Re: git: fc90f3a28145 - main - ktrace: Increase precision of
 timestamps.
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 <YtLCnMfU/glHru1j@kib.kiev.ua>
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On Sat, Jul 16, 2022 at 04:52:28PM +0300, Konstantin Belousov wrote:
K> >     Replace struct timeval in header with struct timespec.
K> >     To differentiate header formats, add a new KTR_VERSIONED flag
K> >     set in the header type field similar to the existing KTRDROP flag.
K> >     
K> >     To make it easier to extend ktrace headers in the future,
K> >     extend the existing header with a version field (version 0 is
K> >     reserved for older records without KTR_VERSIONED) as well as
K> >     new fields holding the thread ID and CPU ID.
K> It would be nice to have a way to force kernel to write v0 format.
K> 
K> For instance, one of my usual work flow case is to generate ktrace.out
K> on HEAD and kdump it on stable/13.

IMHO, the right way to handle that is to merge new kdump to stable/13,
rather than keeping compat layers in head kernel.

-- 
Gleb Smirnoff