From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 09 Jan 2006 15:27:55 +0000 (GMT) Received: from extgw-uk.mips.com ([62.254.210.129]:3867 "EHLO bacchus.net.dhis.org") by ftp.linux-mips.org with ESMTP id S8134428AbWAIP1h (ORCPT ); Mon, 9 Jan 2006 15:27:37 +0000 Received: from denk.linux-mips.net (denk.linux-mips.net [127.0.0.1]) by bacchus.net.dhis.org (8.13.4/8.13.4) with ESMTP id k09FUS1L006702; Mon, 9 Jan 2006 15:30:28 GMT Received: (from ralf@localhost) by denk.linux-mips.net (8.13.4/8.13.4/Submit) id k09FUSP4006701; Mon, 9 Jan 2006 15:30:28 GMT Date: Mon, 9 Jan 2006 15:30:28 +0000 From: Ralf Baechle To: "Kevin D. Kissell" Cc: Sathesh Babu Edara , linux-mips-bounce@linux-mips.org, linux-mips@linux-mips.org Subject: Re: LL and SC instruction simulation Message-ID: <20060109153028.GA6542@linux-mips.org> References: <200601090742.k097gYaZ017304@lilac.hdcindia.analog.com> <200601090749.k097nFaZ017891@lilac.hdcindia.analog.com> <20060109145425.GA4286@linux-mips.org> <00af01c6152f$dc1863f0$10eca8c0@grendel> <20060109152148.GD4286@linux-mips.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060109152148.GD4286@linux-mips.org> User-Agent: Mutt/1.4.2.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 9817 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Mon, Jan 09, 2006 at 03:21:48PM +0000, Ralf Baechle wrote: > > > Only ll/sc instructions in application software can be emulated, so it > > > would seem your application is behaving different on 2.4 and 2.6 kernels. > > > > Is there an interface where 2.6 might be telling library code to use system calls > > instead LL/SC, where the 2.4 kernel didn't? > > No. And I think it's not really worth it. MIPS II did introduce ll/sc in 1991 and it was becoming widely available with MIPS III and some pseudo- MIPS II R3000 variants also in the embedded markets and MIPS32/MIPS64 were based on that. So ll/sc-less processors are a very small part of the market of Linux/MIPS these days, not really worth to optimize for. Ralf