Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752835AbZIXPDd (ORCPT ); Thu, 24 Sep 2009 11:03:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752403AbZIXPDc (ORCPT ); Thu, 24 Sep 2009 11:03:32 -0400 Received: from tomts10-srv.bellnexxia.net ([209.226.175.54]:39104 "EHLO tomts10-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbZIXPDc (ORCPT ); Thu, 24 Sep 2009 11:03:32 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqIEAD4nu0pMROOX/2dsb2JhbACBUtYBhBsF Date: Thu, 24 Sep 2009 11:03:33 -0400 From: Mathieu Desnoyers To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, "Frank Ch. Eigler" , Hideo AOKI , Takashi Nishiie , Steven Rostedt , Masami Hiramatsu Subject: Re: [patch 12/12] Tracepoints - Immediate Values Message-ID: <20090924150333.GA26389@Krystal> References: <20090924132626.485545323@polymtl.ca> <20090924133400.830759403@polymtl.ca> <1253803872.18939.28.camel@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <1253803872.18939.28.camel@laptop> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.27.31-grsec (i686) X-Uptime: 10:57:35 up 37 days, 1:47, 2 users, load average: 0.27, 0.26, 0.25 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 Content-Length: 1189 Lines: 33 * Peter Zijlstra (peterz@infradead.org) wrote: > On Thu, 2009-09-24 at 09:26 -0400, Mathieu Desnoyers wrote: > > plain text document attachment (tracepoints-immediate-values.patch) > > Use immediate values in tracepoints. > > I might have missed it, but did both the Intel and AMD cpu folks clear > the SMP code rewrite bits? > SMP handling is performed with stop_machine() in this patchset. Nothing fancy here. I've got other patches, not included in this patchset, which implements nmi-safe code modification, based on a scheme using breakpoints and IPIs, inspired from djprobes. That one might be worth clearing with intel/amd devs before merging. However, doing code patching within stop_machine() is pretty safe, given all other CPUs are busy-looping with interrupts off while this happens. Ftrace already does this. Thanks, Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/