From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933024AbXGKUKV (ORCPT ); Wed, 11 Jul 2007 16:10:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763609AbXGKUKK (ORCPT ); Wed, 11 Jul 2007 16:10:10 -0400 Received: from nz-out-0506.google.com ([64.233.162.227]:57794 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760231AbXGKUKI (ORCPT ); Wed, 11 Jul 2007 16:10:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=EpMg+fl0IqmruDJW3KmzZb8KQfiXN7AqUlBDbHkDUAdkbWp99dcx+WWIWtwDbisNVImk3uSbxYuENKCioi4bET38PcvIEBk9amKZn4tbNbZap57IYq60cuYYRA3aOTU1acVPp0C0lQk/vTGqRtor8mzB6hKeqSGfIzKVo2o1t5s= Message-ID: <68676e00707111310v4862974am37dc7c723486b96c@mail.gmail.com> Date: Wed, 11 Jul 2007 22:10:07 +0200 From: Luca To: "Avi Kivity" Subject: Re: [kvm-devel] [PATCH 2/2] KVM: Use the scheduler preemption hooks to make kvm preemptible Cc: kvm-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org In-Reply-To: <1184169333786-git-send-email-avi@qumranet.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <11841693332609-git-send-email-avi@qumranet.com> <1184169333786-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 7/11/07, Avi Kivity wrote: > Current kvm disables preemption while the new virtualization registers are > in use. This of course is not very good for latency sensitive workloads (one > use of virtualization is to offload user interface and other latency > insensitive stuff to a container, so that it is easier to analyze the > remaining workload). This patch re-enables preemption for kvm; preemption > is now only disabled when switching the registers in and out, and during > the switch to guest mode and back. [...] > diff --git a/drivers/kvm/Kconfig b/drivers/kvm/Kconfig > index 33fa28a..92644b5 100644 > --- a/drivers/kvm/Kconfig > +++ b/drivers/kvm/Kconfig > @@ -10,7 +10,7 @@ if VIRTUALIZATION > > config KVM > tristate "Kernel-based Virtual Machine (KVM) support" > - depends on X86 && EXPERIMENTAL > + depends on X86 && EXPERIMENTAL && PREEMPT_HOOKS > depends on X86_CMPXCHG64 || 64BIT select PREEMPT_HOOKS maybe? Luca