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Date: Sat, 17 Dec 2005 14:38:24 -0800
From: Richard Henderson <rth@twiddle.net>
Subject: Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation
Message-ID: <20051217223824.GA16736@twiddle.net>
References: <Pine.LNX.4.64.0512160829180.3060@g5.osdl.org> <20051216.142349.89717140.davem@davemloft.net> <Pine.LNX.4.64.0512161429500.3698@g5.osdl.org> <20051216.145306.132052494.davem@davemloft.net>
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To: "David S. Miller" <davem@davemloft.net>
Cc: torvalds@osdl.org, dhowells@redhat.com, nickpiggin@yahoo.com.au, arjan@infradead.org, akpm@osdl.org, alan@lxorguk.ukuu.org.uk, cfriesen@nortel.com, hch@infradead.org, matthew@wil.cx, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
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On Fri, Dec 16, 2005 at 02:53:06PM -0800, David S. Miller wrote:
> I'll have to add "put write prefetch in CAS sequences" onto my sparc64
> TODO list :-)

You might consider just beginning your loops like

	mov	zero, old
	cas	[mem], zero, old

to do the initial read, since old will now contain the 
contents of the memory, and we havn't changed the memory.


r~