From owner-freebsd-alpha  Sat Nov  9 16:11:25 2002
Delivered-To: freebsd-alpha@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id EF6A937B401; Sat,  9 Nov 2002 16:11:24 -0800 (PST)
Received: from beppo.feral.com (beppo.feral.com [192.67.166.79])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 49B5D43E4A; Sat,  9 Nov 2002 16:11:24 -0800 (PST)
	(envelope-from mjacob@feral.com)
Received: from mailhost.feral.com (mjacob@mailhost.feral.com [192.67.166.1])
	by beppo.feral.com (8.11.3/8.11.3) with ESMTP id gAA0B9Z52968;
	Sat, 9 Nov 2002 16:11:14 -0800 (PST)
	(envelope-from mjacob@feral.com)
Date: Sat, 9 Nov 2002 16:11:08 -0800 (PST)
From: Matthew Jacob <mjacob@feral.com>
X-Sender: mjacob@beppo
Reply-To: mjacob@feral.com
To: "Alan L. Cox" <alc@imimic.com>
Cc: Jeff Roberson <jroberson@chesapeake.net>,
	Andrew Gallatin <gallatin@cs.duke.edu>, alpha@FreeBSD.ORG,
	alc@FreeBSD.ORG, John Baldwin <jhb@FreeBSD.ORG>
Subject: Re: alpha: top of tree kernel blooie
In-Reply-To: <3DCD7244.DEEA7387@imimic.com>
Message-ID: <Pine.BSF.4.21.0211091602040.52837-100000@beppo>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-alpha@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-alpha.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-alpha>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-alpha>
X-Loop: FreeBSD.org

> 
> 2. Don't we compile by default for the older Alphas that lack byte
> manipulation instructions?  Thus, a byte store is implemented by a
> read-modify-write sequence of instructions.  Thus, two simultaneous
> uma_dbg_alloc()s on adjacent locations in us_freelist could cause
> corruption.

The processors on the 4100 are ev56:

CPU: EV56 (21164A) major=7 minor=2 extensions=0x1<BWX>

but I see your point uma_dbg_alloc/uma_dbg_free. The correct code here
should be atomic_set_char and atomic_clear_char I would think.






To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-alpha" in the body of the message