Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753503Ab1BPUNh (ORCPT ); Wed, 16 Feb 2011 15:13:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:8642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751731Ab1BPUNe (ORCPT ); Wed, 16 Feb 2011 15:13:34 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Mathieu Desnoyers X-Fcc: ~/Mail/linus Cc: Mark Wielaard , Stefan Hajnoczi , "Frank Ch. Eigler" , Julien Desfossez , dominique.toupin@ericsson.com, ltt-dev@lists.casi.polymtl.ca, systemtap@sources.redhat.com, linux-kernel@vger.kernel.org, Jason Baron , hpa@zytor.com, rostedt@goodmis.org, mingo@elte.hu, tglx@linutronix.de, andi@firstfloor.org, rth@redhat.com, masami.hiramatsu.pt@hitachi.com, fweisbec@gmail.com, avi@redhat.com, davem@davemloft.net, sam@ravnborg.org, ddaney@caviumnetworks.com, michael@ellerman.id.au, Peter Zijlstra Subject: Re: Porting "jump labels" to userspace (was: Re: [ltt-dev] LTTng-UST vs SystemTap userspace tracing benchmarks) In-Reply-To: Mathieu Desnoyers's message of Wednesday, 16 February 2011 15:00:34 -0500 <20110216200034.GA6066@Krystal> References: <4D5AA164.1050607@polymtl.ca> <1297853778.3224.90.camel@springer.wildebeest.org> <20110216185056.CAD7B1806E0@magilla.sf.frob.com> <20110216200034.GA6066@Krystal> X-Windows: it could be worse, but it'll take time. Message-Id: <20110216200449.1EB9618020E@magilla.sf.frob.com> Date: Wed, 16 Feb 2011 12:04:49 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 739 Lines: 16 IMHO there is not really so much to the in-kernel implementation that it's worth attempting to reuse the code in userland. Pretty much all the work is in the details of the implementation that would naturally differ a lot in a different context. If you understand the mechanism and the machine details, then implementing it well for a userland context is not a big deal and is cleaner to do from scratch than shoe-horning kernel-centric code into a wildly different context. Thanks, Roland -- 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/