From owner-freebsd-current Mon Mar 20 13:53:49 2000 Delivered-To: freebsd-current@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.40.131]) by hub.freebsd.org (Postfix) with ESMTP id 6602337B78C for ; Mon, 20 Mar 2000 13:53:26 -0800 (PST) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost.freebsd.dk [127.0.0.1]) by critter.freebsd.dk (8.9.3/8.9.3) with ESMTP id WAA21215; Mon, 20 Mar 2000 22:52:59 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Alfred Perlstein Cc: Matthew Dillon , current@FreeBSD.ORG Subject: Re: patches for test / review In-reply-to: Your message of "Mon, 20 Mar 2000 11:59:02 PST." <20000320115902.C14789@fw.wintelcom.net> Date: Mon, 20 Mar 2000 22:52:59 +0100 Message-ID: <21213.953589179@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <20000320115902.C14789@fw.wintelcom.net>, Alfred Perlstein writes: >* Poul-Henning Kamp [000320 11:45] wrote: >> In message <20000320111544.A14789@fw.wintelcom.net>, Alfred Perlstein writes: >> >> >Keeping the currect cluster code is a bad idea, if the drivers were >> >taught how to traverse the linked list in the buf struct rather >> >than just notice "a big buffer" we could avoid a lot of page >> >twiddling and also allow for massive IO clustering ( > 64k ) >> >> Before we redesign the clustering, I would like to know if we >> actually have any recent benchmarks which prove that clustering >> is overall beneficial ? > >Yes it is really benificial. > >I'm not talking about a redesign of the clustering code as much as >making the drivers that take a callback from it actually traverse >the 'union cluster_info' rather than relying on the system to fake >the pages being contiguous via remapping. > >There's nothing wrong with the clustering algorithms, it's just the >steps it has to take to work with the drivers. Hmm, try to keep vinum/RAID5 in the picture when you look at this code, it complicated matters a lot. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message