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From: David Howells <dhowells@redhat.com>
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Subject: Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation 
Date: Fri, 16 Dec 2005 11:30:01 +0000
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Sender: dhowells@redhat.com
To: David Howells <dhowells@redhat.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>, Arjan van de Ven <arjan@infradead.org>, Andrew Morton <akpm@osdl.org>, Alan Cox <alan@lxorguk.ukuu.org.uk>, cfriesen@nortel.com, torvalds@osdl.org, hch@infradead.org, matthew@wil.cx, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
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David Howells <dhowells@redhat.com> wrote:

> No, they're not. LL/SC is more flexible than CMPXCHG because under some
> circumstances, you can get away without doing the SC,

Of course, CMPXCHG doesn't have to store either, though it still performs a
locked-write-cycle on x86 if I remember correctly.

David