Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755315AbYJBQce (ORCPT ); Thu, 2 Oct 2008 12:32:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753911AbYJBQc0 (ORCPT ); Thu, 2 Oct 2008 12:32:26 -0400 Received: from pasmtpb.tele.dk ([80.160.77.98]:54265 "EHLO pasmtpB.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753844AbYJBQcZ (ORCPT ); Thu, 2 Oct 2008 12:32:25 -0400 Date: Thu, 2 Oct 2008 18:32:05 +0200 From: Jens Axboe To: Leon Woestenberg Cc: "Leisner, Martin" , Alan Cox , marty , linux-kernel@vger.kernel.org Subject: Re: disk IO directly from PCI memory to block device sectors Message-ID: <20081002163205.GJ19428@kernel.dk> References: <247018.46515.qm@web50603.mail.re2.yahoo.com> <20080926094653.1e0a9260@lxorguk.ukuu.org.uk> <20080926091135.GV2677@kernel.dk> <556445368AFA1C438794ABDA8901891C0999203A@USA0300MS03.na.xerox.net> <20080929130222.GX2677@kernel.dk> <20081001190546.GQ19428@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1655 Lines: 46 On Thu, Oct 02 2008, Leon Woestenberg wrote: > Hello Jens, > > On Wed, Oct 1, 2008 at 9:05 PM, Jens Axboe wrote: > > On Mon, Sep 29 2008, Jens Axboe wrote: > >> On Fri, Sep 26 2008, Leisner, Martin wrote: > >> IMHO, this interface totally rocks. It's really async like splice was > > > > Alright, so this one actually works :-) > > Apart from fixing the bugs in it, it's also more clever in using the bio > > for the write part. It'll reuse the same bio in the splice actor until > > it's full, only then submitting it and allocating a new one. The read > > part works the same way. > > > I have been following this thread trying to grasp a very nifty use > case (high speed acquisition and storage of data) of splice. > > I think it would make a perfect example of splice functionality. > > What would the user space part look like to exercise this interface? Download: http://brick.kernel.dk/snaps/splice-git-latest.tar.gz which has lots of little examples for splice. You would want to do something ala # splice-in /dev/my-pci-device | splice-out /dev/sda in one app of course, but take a look at the examples and get a feel for the interface... BTW, in my splice branch I have this queued as well. Not going anywhere for now, but should get updated and tested every now and then. http://git.kernel.dk/?p=linux-2.6-block.git;a=shortlog;h=refs/heads/splice -- Jens Axboe -- 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/