Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758154AbZCaWX0 (ORCPT ); Tue, 31 Mar 2009 18:23:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757680AbZCaWXO (ORCPT ); Tue, 31 Mar 2009 18:23:14 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:55603 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757562AbZCaWXM (ORCPT ); Tue, 31 Mar 2009 18:23:12 -0400 Message-ID: <49D29797.80200@garzik.org> Date: Tue, 31 Mar 2009 18:22:15 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Ric Wheeler CC: Jens Axboe , Linus Torvalds , Theodore Tso , Ingo Molnar , Alan Cox , Arjan van de Ven , Andrew Morton , Mark Lord , Linux Kernel Mailing List , Linux IDE mailing list Subject: Re: Linux 2.6.29 References: <20090324093245.GA22483@elte.hu> <20090324101011.6555a0b9@lxorguk.ukuu.org.uk> <20090324103111.GA26691@elte.hu> <20090324132032.GK5814@mit.edu> <20090324184549.GE32307@mit.edu> <49C93AB0.6070300@garzik.org> <20090325093913.GJ27476@kernel.dk> <49CA86BD.6060205@garzik.org> <20090325194341.GB27476@kernel.dk> <49D281D8.8030203@garzik.org> <49D2930A.5030905@redhat.com> In-Reply-To: <49D2930A.5030905@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.5 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1458 Lines: 38 Ric Wheeler wrote: > Jeff Garzik wrote: >> Jens Axboe wrote: >>> Another problem is that FLUSH_CACHE sucks. Really. And not just on >>> ext3/ordered, generally. Write a 50 byte file, fsync, flush cache and >>> wit for the world to finish. Pretty hard to teach people to use a nicer >>> fdatasync(), when the majority of the cost now becomes flushing the >>> cache of that 1TB drive you happen to have 8 partitions on. Good luck >>> with that. >> >> (responding to an email way back near the start of the thread) >> >> I emailed Microsoft about their proposal to add a WRITE BARRIER >> command to ATA, documented at >> http://www.t13.org/Documents/UploadedDocuments/docs2007/e07174r0-Write_Barrier_Command_Proposal.doc >> The MSFT engineer said they were definitely still pursuing this proposal. >> >> IMO we could look at this too, or perhaps come up with an alternate >> proposal like FLUSH CACHE RANGE(s). > I agree that it is worth getting better mechanisms in place - the cache > flush is really primitive. Now we just need a victim to sit in on > T13/T10 standards meetings :-) Heck, we could even do a prototype implementation with the help of Mark Lord's sata_mv target mode support... Jeff -- 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/