From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932743Ab2ISRXJ (ORCPT ); Wed, 19 Sep 2012 13:23:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15465 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932321Ab2ISRXF (ORCPT ); Wed, 19 Sep 2012 13:23:05 -0400 Message-ID: <5059FF67.6050005@redhat.com> Date: Wed, 19 Sep 2012 20:22:47 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120828 Thunderbird/15.0 MIME-Version: 1.0 To: Suresh Siddha CC: hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, andreas.herrmann3@amd.com, bp@amd64.org, robert.richter@amd.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/6] x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() References: <1345842782-24175-1-git-send-email-suresh.b.siddha@intel.com> <1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com> <50599AE2.80601@redhat.com> <1348075103.26695.301.camel@sbsiddha-desk.sc.intel.com> In-Reply-To: <1348075103.26695.301.camel@sbsiddha-desk.sc.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/19/2012 08:18 PM, Suresh Siddha wrote: > These routines (kvm_load/put_guest_fpu()) are already called with > preemption disabled but as you mentioned, we don't want the preemption > to be disabled completely between the kvm_load_guest_fpu() and > kvm_put_guest_fpu(). > > Also KVM already has the preempt notifier which is doing the > kvm_put_guest_fpu(), so something like the appended should address this. > I will test this shortly. > Note, we could also go in a different direction and make kernel_fpu_begin() use preempt notifiers and thus make its users preemptible. But that's for a separate patchset. -- error compiling committee.c: too many arguments to function