Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264257AbTEZEr7 (ORCPT ); Mon, 26 May 2003 00:47:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264259AbTEZEr6 (ORCPT ); Mon, 26 May 2003 00:47:58 -0400 Received: from notes.hallinto.turkuamk.fi ([195.148.215.149]:24338 "EHLO notes.hallinto.turkuamk.fi") by vger.kernel.org with ESMTP id S264257AbTEZEr5 (ORCPT ); Mon, 26 May 2003 00:47:57 -0400 Message-ID: <3ED1A0FE.3000101@kolumbus.fi> Date: Mon, 26 May 2003 08:07:10 +0300 From: =?ISO-8859-15?Q?Mika_Penttil=E4?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.2) Gecko/20030208 Netscape/7.02 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "David S. Miller" CC: Russell King , Andrew Morton , Hugh Dickins , LW@KARO-electronics.de, linux-kernel@vger.kernel.org Subject: Re: [patch] cache flush bug in mm/filemap.c (all kernels >= 2.5.30(at least)) References: <20030523175413.A4584@flint.arm.linux.org.uk> <20030523112926.7c864263.akpm@digeo.com> <20030523193458.B4584@flint.arm.linux.org.uk> <1053919171.14018.2.camel@rth.ninka.net> X-MIMETrack: Itemize by SMTP Server on marconi.hallinto.turkuamk.fi/TAMK(Release 5.0.8 |June 18, 2001) at 26.05.2003 08:02:17, Serialize by Router on notes.hallinto.turkuamk.fi/TAMK(Release 5.0.10 |March 22, 2002) at 26.05.2003 08:01:48, Serialize complete at 26.05.2003 08:01:48 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-15; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1226 Lines: 43 I don't think the flush_dcache_page thing is done almost anywhere in the block/driver level right now. And we shouldn't be doing io reads to pagecache pages with user mappings anyway normally. direct-io is a different thing. --Mika David S. Miller wrote: >On Fri, 2003-05-23 at 11:34, Russell King wrote: > > >>So no, I don't think it is a device driver issue at all. >> >>DaveM? >> >> > >Oh yes, this part is. If you don't ensure this, everything >breaks. > >At the end of an I/O operation, say to a page cache page, that >data ought to be visible equally to a userspace vs. a kernel >space mapping to that page. > >For example, this is why we use language about "cpu visibility" in the >DMA api documentation and not "kernel cpu visibility" :-) And because >PIO transfers are basically pseudo-DMA they need to make the same exact >guarentees. > >If you've been living in a world where you didn't think this is >necessary, I certainly feel bad for you :-) > > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/