From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754248AbZB1InS (ORCPT ); Sat, 28 Feb 2009 03:43:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752322AbZB1InK (ORCPT ); Sat, 28 Feb 2009 03:43:10 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:35036 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752065AbZB1InI (ORCPT ); Sat, 28 Feb 2009 03:43:08 -0500 Date: Sat, 28 Feb 2009 09:42:54 +0100 From: Ingo Molnar To: Andrew Morton Cc: Jeremy Fitzhardinge , "H. Peter Anvin" , the arch/x86 maintainers , Linux Kernel Mailing List , Xen-devel Subject: Re: [PATCH] xen: core dom0 support Message-ID: <20090228084254.GA29342@elte.hu> References: <1235786365-17744-1-git-send-email-jeremy@goop.org> <20090227212812.26d02f34.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090227212812.26d02f34.akpm@linux-foundation.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Morton wrote: > I hate to be the one to say it, but we should sit down and > work out whether it is justifiable to merge any of this into > Linux. I think it's still the case that the Xen technology is > the "old" way and that the world is moving off in the "new" > direction, KVM? > > In three years time, will we regret having merged this? Personally i'd like to see a sufficient reply to the mmap-perf paravirt regressions pointed out by Nick and reproduced by myself as well. (They were in the 4-5% macro-performance range iirc, which is huge.) So i havent seen any real progress on reducing native kernel overhead with paravirt. Patches were sent but no measurements were done and it seemed to have all fizzled out while the dom0 patches are being pursued. Which is not a particularly good basis on which to add even _more_ paravirt stuff, is it? Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH] xen: core dom0 support Date: Sat, 28 Feb 2009 09:42:54 +0100 Message-ID: <20090228084254.GA29342@elte.hu> References: <1235786365-17744-1-git-send-email-jeremy@goop.org> <20090227212812.26d02f34.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20090227212812.26d02f34.akpm@linux-foundation.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andrew Morton Cc: Xen-devel , Jeremy Fitzhardinge , the arch/x86 maintainers , Linux Kernel Mailing List , "H. Peter Anvin" List-Id: xen-devel@lists.xenproject.org * Andrew Morton wrote: > I hate to be the one to say it, but we should sit down and > work out whether it is justifiable to merge any of this into > Linux. I think it's still the case that the Xen technology is > the "old" way and that the world is moving off in the "new" > direction, KVM? > > In three years time, will we regret having merged this? Personally i'd like to see a sufficient reply to the mmap-perf paravirt regressions pointed out by Nick and reproduced by myself as well. (They were in the 4-5% macro-performance range iirc, which is huge.) So i havent seen any real progress on reducing native kernel overhead with paravirt. Patches were sent but no measurements were done and it seemed to have all fizzled out while the dom0 patches are being pursued. Which is not a particularly good basis on which to add even _more_ paravirt stuff, is it? Ingo