Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755353AbYJFROB (ORCPT ); Mon, 6 Oct 2008 13:14:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753566AbYJFRNx (ORCPT ); Mon, 6 Oct 2008 13:13:53 -0400 Received: from tomts20.bellnexxia.net ([209.226.175.74]:36668 "EHLO tomts20-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752641AbYJFRNx (ORCPT ); Mon, 6 Oct 2008 13:13:53 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AtsEAJPi6UhMQWq+/2dsb2JhbACBcbppgWo Date: Mon, 6 Oct 2008 13:13:48 -0400 From: Mathieu Desnoyers To: Steven Rostedt Cc: Ingo Molnar , LKML , Thomas Gleixner , Peter Zijlstra , Andrew Morton , Linus Torvalds , Arjan van de Ven Subject: Re: [PATCH 0/3] ring-buffer: less locking and only disable preemption Message-ID: <20081006171348.GB9345@Krystal> References: <20081004060057.660306328@goodmis.org> <20081004084002.GE27624@elte.hu> <20081004163348.GA23593@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 13:10:46 up 123 days, 21:51, 9 users, load average: 0.09, 0.30, 0.38 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1289 Lines: 40 * Steven Rostedt (rostedt@goodmis.org) wrote: > > On Sat, 4 Oct 2008, Mathieu Desnoyers wrote: > > > > Or use this code, based on a temporary breakpoint, to do the code > > patching (part of the -lttng tree). It does not require stop_machine at > > all and is nmi safe. > > > > When this is supported for all archs, and can be done at all functions > then I could use it. > How about incrementally using this piece of infrastructure when available on a given architecture ? This way we keep a sub-optimal fall-back for archs which does not support NMI-safe code patching and incrementally get the optimal behavior. Otherwise, we would require any new architecture to implement that up-front, which I doubt is a good idea. > I may just have the arch specific code use it, but we'll see. > > Also, how good is it at patching 20,000 call sites? > Can be done really fast using a hash table, see my previous mail. Mathieu > -- Steve > -- 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/