From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 20 Dec 2004 13:15:03 +0000 (GMT) Received: from webmail.ict.ac.cn ([IPv6:::ffff:159.226.39.7]:47833 "HELO ict.ac.cn") by linux-mips.org with SMTP id ; Mon, 20 Dec 2004 13:14:58 +0000 Received: (qmail 30447 invoked by uid 507); 20 Dec 2004 13:13:36 -0000 Received: from unknown (HELO ict.ac.cn) (fxzhang@159.226.40.187) by ict.ac.cn with SMTP; 20 Dec 2004 13:13:36 -0000 Message-ID: <41C6D028.5020004@ict.ac.cn> Date: Mon, 20 Dec 2004 21:14:16 +0800 From: Fuxin Zhang User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040122 X-Accept-Language: zh-cn, en-us MIME-Version: 1.0 To: wuming CC: linux-mips@linux-mips.org Subject: Re: problem about dma References: <001501c4e646$7f676c00$6f64a8c0@spark> <41C690CF.2010306@niisi.msk.ru> <002101c4e679$72938bc0$6f64a8c0@spark> In-Reply-To: <002101c4e679$72938bc0$6f64a8c0@spark> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit 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: 6715 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: fxzhang@ict.ac.cn Precedence: bulk X-list: linux-mips I think that speculative loads may be the answer. wuming wrote: >----- Original Message ----- >From: "Gleb O. Raiko" >To: "wuming" >Cc: >Sent: Monday, December 20, 2004 4:43 PM >Subject: Re: problem about dma > > > > >>In 2.4, memcpy's prefetch may (and, in practice, do, no smiles, it cost >>me a lot of time to realize) access that memory. I though it has been >>fixed in 2.6 someday. >> >>Regards, >>Gleb. >> >> >> >Thank you! :) >But I think it is not the only reason, because the CPU on my platform does not >support the "pref" instruction. So, memcpy's prefetch may have no effect on that >arrange of memory. > > >