From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757562AbZFOWtU (ORCPT ); Mon, 15 Jun 2009 18:49:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751474AbZFOWtJ (ORCPT ); Mon, 15 Jun 2009 18:49:09 -0400 Received: from tomts16.bellnexxia.net ([209.226.175.4]:54378 "EHLO tomts16-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbZFOWtI (ORCPT ); Mon, 15 Jun 2009 18:49:08 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AokFAEZoNkpMQWQl/2dsb2JhbACBT9JVhA0F Date: Mon, 15 Jun 2009 18:49:08 -0400 From: Mathieu Desnoyers To: "H. Peter Anvin" Cc: Ingo Molnar , Peter Zijlstra , Linus Torvalds , mingo@redhat.com, paulus@samba.org, acme@redhat.com, linux-kernel@vger.kernel.org, penberg@cs.helsinki.fi, vegard.nossum@gmail.com, efault@gmx.de, jeremy@goop.org, npiggin@suse.de, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:perfcounters/core] perf_counter: x86: Fix call-chain support to use NMI-safe methods Message-ID: <20090615224908.GA16661@Krystal> References: <4A36A1C7.6080005@zytor.com> <20090615210119.GD24554@elte.hu> <20090615211207.GB12919@Krystal> <20090615211605.GC27100@elte.hu> <20090615213429.GD12919@Krystal> <4A36BF61.10901@zytor.com> <20090615215420.GE12919@Krystal> <4A36C953.8060906@zytor.com> <20090615223038.GA15903@Krystal> <4A36CCFC.8070908@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <4A36CCFC.8070908@zytor.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 18:47:10 up 107 days, 19:13, 4 users, load average: 0.41, 0.84, 0.70 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * H. Peter Anvin (hpa@zytor.com) wrote: > Mathieu Desnoyers wrote: > > > > I'm just thinking that touching or not vmalloc'd areas should not be the > > first thing that comes into the mind of someone willing to write a > > nmi-hooking tracer or oprofile module. > > > > But is HAS to be. Otherwise you're in deadlock city anyway. > Where is the kernel page fault handler grabbing any lock to service in-kernel page faults exactly ? Those are usually considered as utterly simple page table fixups, nothing more. Mathieu > -hpa > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68