From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Kirch Subject: Re: NFS direct IO needs page lock? Date: Thu, 17 Feb 2005 16:34:51 +0100 Message-ID: <20050217153451.GL23564@suse.de> References: <20050215203654.GA15634@suse.de> <1108507882.10073.236.camel@lade.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfs@lists.sourceforge.net Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1D1ngC-0003NU-5e for nfs@lists.sourceforge.net; Thu, 17 Feb 2005 07:35:00 -0800 Received: from mail.suse.de ([195.135.220.2] helo=Cantor.suse.de) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.41) id 1D1ngB-00041z-EH for nfs@lists.sourceforge.net; Thu, 17 Feb 2005 07:35:00 -0800 To: Trond Myklebust In-Reply-To: <1108507882.10073.236.camel@lade.trondhjem.org> Sender: nfs-admin@lists.sourceforge.net Errors-To: nfs-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Post: List-Help: List-Subscribe: , List-Archive: On Tue, Feb 15, 2005 at 05:51:22PM -0500, Trond Myklebust wrote: > ty den 15.02.2005 Klokka 21:36 (+0100) skreiv Olaf Kirch: > It is intentional. Andrew Morton pointed out that you can play zero-copy > tricks by doing direct-io on an mmapped range of pages (as seems to be > the case above). > > That could cause deadlocks if the reader and writer were to both try to > lock the same page. Thanks, that helps! Olaf -- Olaf Kirch | --- o --- Nous sommes du soleil we love when we play okir@suse.de | / | \ sol.dhoop.naytheet.ah kin.ir.samse.qurax ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs