From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750893AbVKJOBR (ORCPT ); Thu, 10 Nov 2005 09:01:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750902AbVKJOBR (ORCPT ); Thu, 10 Nov 2005 09:01:17 -0500 Received: from ns1.suse.de ([195.135.220.2]:45517 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1750893AbVKJOBO (ORCPT ); Thu, 10 Nov 2005 09:01:14 -0500 From: Andi Kleen To: "Jan Beulich" Subject: Re: [PATCH 20/39] NLKD/x86-64 - switch_to() floating point adjustment Date: Thu, 10 Nov 2005 14:24:53 +0100 User-Agent: KMail/1.8 Cc: linux-kernel@vger.kernel.org, discuss@x86-64.org References: <43720DAE.76F0.0078.0@novell.com> <43721239.76F0.0078.0@novell.com> <4372127F.76F0.0078.0@novell.com> In-Reply-To: <4372127F.76F0.0078.0@novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200511101424.53484.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 09 November 2005 15:15, Jan Beulich wrote: > Touching of the floating point state in a kernel debugger must be > NMI-safe, specifically math_state_restore() must be able to deal with > being called out of an NMI context. In order to do that reliably, the > context switch code must take care to not leave a window open where > the current task's TS_USEDFPU flag and CR0.TS could get out of sync. Didn't we agree earlier on moving unlazy_fpu() down instead? -Andi