From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263058AbTJJQ6i (ORCPT ); Fri, 10 Oct 2003 12:58:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263064AbTJJQ6i (ORCPT ); Fri, 10 Oct 2003 12:58:38 -0400 Received: from zcars0m9.nortelnetworks.com ([47.129.242.157]:442 "EHLO zcars0m9.nortelnetworks.com") by vger.kernel.org with ESMTP id S263058AbTJJQ6h (ORCPT ); Fri, 10 Oct 2003 12:58:37 -0400 Message-ID: <3F86E51D.3090605@nortelnetworks.com> Date: Fri, 10 Oct 2003 12:58:05 -0400 X-Sybari-Space: 00000000 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.8) Gecko/20020204 X-Accept-Language: en-us MIME-Version: 1.0 To: Joel Becker Cc: Jamie Lokier , Linus Torvalds , Trond Myklebust , Ulrich Drepper , Linux Kernel Subject: Re: statfs() / statvfs() syscall ballsup... References: <20031010122755.GC22908@ca-server1.us.oracle.com> <20031010152710.GA28773@ca-server1.us.oracle.com> <20031010160144.GI28795@mail.shareable.org> <20031010163300.GC28773@ca-server1.us.oracle.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Joel Becker wrote: > On Fri, Oct 10, 2003 at 05:01:44PM +0100, Jamie Lokier wrote: > >>Why don't you _share_ the App's cache with the kernel's? That's what >>mmap() and remap_file_pages() are for. > Because you can't force flush/read. You can't say "I need you > to go to disk for this." According to my man pages, this is exactly what msync() is for, no? >>That's tough to guarantee at the platter level regardless of O_DIRECT, >>but otherwise: you have fdatasync() and msync(). > Platter level doesn't matter. Storage access level matters. > Node1 and Node2 have to see the same thing. As long as I am absolutely > sure that when Node1's write() returns, any subsequent read() on Node2 > will see the change (normal barrier stuff, really), it doesn't matter > what happend on the Storage. Isn't that exactly what msync() exists for? Chris -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com