From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262419AbTJJRya (ORCPT ); Fri, 10 Oct 2003 13:54:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263024AbTJJRya (ORCPT ); Fri, 10 Oct 2003 13:54:30 -0400 Received: from pat.uio.no ([129.240.130.16]:59026 "EHLO pat.uio.no") by vger.kernel.org with ESMTP id S262419AbTJJRy2 (ORCPT ); Fri, 10 Oct 2003 13:54:28 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16262.62026.603149.157026@charged.uio.no> Date: Fri, 10 Oct 2003 13:54:18 -0400 To: Linus Torvalds Cc: Joel Becker , Chris Friesen , Jamie Lokier , Linux Kernel Subject: Re: statfs() / statvfs() syscall ballsup... In-Reply-To: References: <20031010172001.GA29301@ca-server1.us.oracle.com> X-Mailer: VM 7.07 under 21.4 (patch 8) "Honest Recruiter" XEmacs Lucid Reply-To: trond.myklebust@fys.uio.no From: Trond Myklebust X-MailScanner-Information: This message has been scanned for viruses/spam. Contact postmaster@uio.no if you have questions about this scanning. X-UiO-MailScanner: No virus found Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> " " == Linus Torvalds writes: > On Fri, 10 Oct 2003, Joel Becker wrote: >> >> msync() forces write(), like fsync(). It doesn't force read(). > Actually, the kernel has a "readahead(fd, offset, size)" system > call that will start asynchronous read-ahead on any > mapping. After that, just touching the page will obviously map > in and synchronize the result. That's different. That's just preheating the page cache. It does nothing for the case Joel mentioned where 2 different nodes are writing to the same device, and you need to force a read in order to resynchronize the page cache. Apart from O_DIRECT, we have nothing in the kernel as it stands that will allow userland to deal with this case. Cheers, Trond