From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932237Ab3BSEYS (ORCPT ); Mon, 18 Feb 2013 23:24:18 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:13268 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755133Ab3BSEYQ (ORCPT ); Mon, 18 Feb 2013 23:24:16 -0500 X-Authority-Analysis: v=2.0 cv=It2cgcDg c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=8jnvGVjTqY4A:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=_67WK3i7ub8A:10 a=zyRtYEcVor_Ib2cA_PgA:9 a=PUjeQqilurYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-ID: <1361247854.23152.198.camel@gandalf.local.home> Subject: Re: [PATCH v9 2/3] trace,x86: add x86 irq vector tracepoints From: Steven Rostedt To: "H. Peter Anvin" Cc: Seiji Aguchi , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "Thomas Gleixner (tglx@linutronix.de)" , "'mingo@elte.hu' (mingo@elte.hu)" , "Borislav Petkov (bp@alien8.de)" , Satoru Moriya , "dle-develop@lists.sourceforge.net" , "linux-edac@vger.kernel.org" , "Luck, Tony (tony.luck@intel.com)" Date: Mon, 18 Feb 2013 23:24:14 -0500 In-Reply-To: <5122BE0C.9020403@zytor.com> References: <511ECE53.8040801@zytor.com> <1360979993.23152.122.camel@gandalf.local.home> <511EEAE1.1040106@zytor.com> <1360981364.23152.123.camel@gandalf.local.home> <5122BE0C.9020403@zytor.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2013-02-18 at 15:49 -0800, H. Peter Anvin wrote: > What about the following: > > > The base address of the IDT doesn't generally change... the one > > exception is when we do the funny NMI workaround. > > > > For that reason, I would be happier if we just restored the standard > > value instead of saving/restoring stuff. Basically what you are saying, is to have his code do what the NMI code originally did, but can't now, due to there being another IDT table (from Seiji's changes). static void switch_to_trace_idt(void *arg) { load_idt(&trace_idt_descr); } static void restore_original_idt(void *arg) { load_idt(this_cpu_ptr(&idt_descr)); } -- Steve