From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 381D46B01CA for ; Fri, 18 Jun 2010 08:18:40 -0400 (EDT) Date: Fri, 18 Jun 2010 08:18:34 -0400 Subject: Re: [Lsf10-pc] Current topics for LSF10/MM Summit 8-9 August in Boston Message-ID: <20100618121833.GB10887@fieldses.org> References: <1276721459.2847.399.camel@mulgrave.site> <20100617160048.GA11689@schmichrtp.mainz.de.ibm.com> <1276790850.7398.8.camel@mulgrave.site> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1276790850.7398.8.camel@mulgrave.site> From: "J. Bruce Fields" Sender: owner-linux-mm@kvack.org To: James Bottomley Cc: Christof Schmitt , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, lsf10-pc@lists.linuxfoundation.org, linux-scsi@vger.kernel.org List-ID: On Thu, Jun 17, 2010 at 11:07:30AM -0500, James Bottomley wrote: > It's actually listed under 'dma issues' ... but there's really been no > satisfactory resolution or discussion of how one might be achieved. > Most filesystems rely on modifications to in-flight pages for efficiency > and copying every fs I/O page would be horrendous both for performance > and memory consumption. Nor has there really been an indication that > it's a serious issue. The two sufferers are DIF and iSCSI checksum. And, again, NFS (both client (on writes) and server (on reads)), when using sec=krb5i. Haven't tried to reproduce the problem, but I believe it would result in spurious IO errors. --b. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org