From: Karel Zak <kzak@redhat.com>
To: Michal Soltys <soltys@ziu.info>
Cc: util-linux@vger.kernel.org
Subject: Re: hwclock recent commits - question
Date: Thu, 20 Dec 2012 09:58:00 +0100 [thread overview]
Message-ID: <20121220085800.GF17959@x2.net.home> (raw)
In-Reply-To: <50D1E252.5070805@ziu.info>
On Wed, Dec 19, 2012 at 04:50:42PM +0100, Michal Soltys wrote:
> Namely regarding commit:
>
> 839be2ba6b44fa9dc927f081d547ebadec9de19c
>
> and subsequent Tom's fix:
>
> 910a090039cbd529041bfb5f6be72bf27a96bd47
>
>
> From what I can see, the "old" and current hwclock's behaviour is actually
> identical, with exception of relying on either warp_clock() call (current
> version, one-shot only) or do_settimeofday() (previous version, consistent
> on each call).
>
> Was the switch to warp_clock() the main reason after the change, or were
> there other issues with standard approach ?
Yes, we want to use the warp_clock(), the problem with the old
version is that without warp_clock() the time will be modified every
time. It's unexpected, because the time should be modified only once
(=during boot).
Unfortunately we have bug reports from "creative people" who are able
to call hwclock --systz more then once. The current warp_clock()
based solution is more robust.
Note that systemd uses the same method to setup system time (it does
not call hwclock).
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
prev parent reply other threads:[~2012-12-20 8:58 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-19 15:50 hwclock recent commits - question Michal Soltys
2012-12-20 8:58 ` Karel Zak [this message]
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