From owner-freebsd-sparc64@FreeBSD.ORG  Tue Feb 15 08:39:43 2005
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To: Kris Kennaway <kris@obsecurity.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Mon, 14 Feb 2005 15:06:35 PST."
             <20050214230635.GA86332@xor.obsecurity.org> 
Date: Tue, 15 Feb 2005 09:39:41 +0100
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cc: sparc64@FreeBSD.org
Subject: Re: System clock died on e420r 
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In message <20050214230635.GA86332@xor.obsecurity.org>, Kris Kennaway writes:

>On Mon, Feb 14, 2005 at 11:14:51PM +0100, Poul-Henning Kamp wrote:
>>=20
>> If hardclock dies, timecounters (like much else) suffers.
>
>Surely, so why is it happening and how can it be fixed? :)
>
>jhb suspected there might be unserialized access to the time counter
>on sparc64.

As far as I know that timecounter is a single register so there is no
need for serialization.  It's only when the hardware requires you
to access multiple times/registers that you need to put locks around it.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.