Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161029AbWJPRsJ (ORCPT ); Mon, 16 Oct 2006 13:48:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161032AbWJPRsJ (ORCPT ); Mon, 16 Oct 2006 13:48:09 -0400 Received: from dhost002-90.dex002.intermedia.net ([64.78.20.228]:15399 "EHLO dhost002-90.dex002.intermedia.net") by vger.kernel.org with ESMTP id S1161029AbWJPRsH (ORCPT ); Mon, 16 Oct 2006 13:48:07 -0400 Message-ID: <4533C596.5060804@qlusters.com> Date: Mon, 16 Oct 2006 19:47:02 +0200 From: Constantine Gavrilov Reply-To: Constantine Gavrilov Organization: Qlusters User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.7.13) Gecko/20060501 Fedora/1.7.13-1.1.fc5 X-Accept-Language: ru, en-us, en MIME-Version: 1.0 To: "Aneesh Kumar K.V" CC: linux-kernel@vger.kernel.org Subject: Re: Would SSI clustering extensions be of interest to kernel community? References: <45337FE3.8020201@qlusters.com> <4533B177.7030004@gmail.com> In-Reply-To: <4533B177.7030004@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 16 Oct 2006 17:48:00.0153 (UTC) FILETIME=[38A0A090:01C6F14B] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2407 Lines: 59 Please see inline... Aneesh Kumar K.V wrote: > > I am interested in seeing the changes. I am right now working on > getting parts of OpenSSI (www.openssi.org) > changes merged upstream. Bruce Walker of the OpenSSI project have a > design of implementing cluster wide procs. The > same doc can be found on www.openssi.org website. The paper talks > about how to implement cluster wide proccess model > without requiring home/deputy concept. But yes it require some core > kernel changes. But should be Conditionally enabled > like selinux. So overhead for non cluster users should be nill. I am personally not interested in making intrusive kernel changes even if it yields in true "single-system image". I want very small changes (preferrably none). > > Regarding my work you can see the status here > http://git.openssi.org/~kvaneesh/gitweb.cgi?p=ci-to-linus.git;a=summary > > It only gets the ICS changes. That means it introduce a transport > independent kernel cluster framework. Right now it supports two > interconnect IPV4 and infiniband verbs. We also have transport abstraction layer and transport plugins for TCP/IP, SDP (Infiniband and possibly others), and SCI (Dolphin). > I am planning on taking the CFS changes. That should bring in > clusterwide shared memory too. The way it was done in OpenSSI > was to hook a new nopage() function for CFS so that when we page > fault, we bring the pages from other node.So i am not sure whether > one need a VM hook for getting clusterwide shared memory. But without > seeing the code i am clueless. > Nopage will be called if there is no pte. That means, with just nopage you cannot implement RO-RW transition. If you use nopage only, you cannot have multiple readers, because you cannot invalidate all other readers if one reader goes read-write. Thus nopage allows single reader or single writer whle the page fault hook allows multiple readers and single writer. -- ---------------------------------------- Constantine Gavrilov Kernel Developer Qlusters Software Ltd 1 Azrieli Center, Tel-Aviv Phone: +972-3-6081977 Fax: +972-3-6081841 ---------------------------------------- - 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/