Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932254Ab0A2Jw0 (ORCPT ); Fri, 29 Jan 2010 04:52:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756717Ab0A2JwZ (ORCPT ); Fri, 29 Jan 2010 04:52:25 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:52603 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756459Ab0A2JwY (ORCPT ); Fri, 29 Jan 2010 04:52:24 -0500 Date: Fri, 29 Jan 2010 10:51:52 +0100 From: Ingo Molnar To: Ananth N Mavinakayanahalli Cc: Jim Keniston , Stephen Rothwell , Kyle Moffett , Arnaldo Carvalho de Melo , Peter Zijlstra , Fr??d??ric Weisbecker , Oleg Nesterov , Steven Rostedt , LKML , Tom Tromey , "Frank Ch. Eigler" , linux-next@vger.kernel.org, "H. Peter Anvin" , utrace-devel@redhat.com, Linus Torvalds , Thomas Gleixner Subject: Re: linux-next: add utrace tree Message-ID: <20100129095152.GA360@elte.hu> References: <1264575134.4283.1983.camel@laptop> <20100127085442.GA28422@elte.hu> <1264643539.5068.62.camel@localhost.localdomain> <20100128085502.GA7713@elte.hu> <1264726768.4933.50.camel@localhost.localdomain> <20100129073907.GF14636@elte.hu> <20100129075240.GF16920@in.ibm.com> <20100129091116.GB10878@elte.hu> <20100129093136.GH16920@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100129093136.GH16920@in.ibm.com> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1687 Lines: 46 * Ananth N Mavinakayanahalli wrote: > On Fri, Jan 29, 2010 at 10:11:16AM +0100, Ingo Molnar wrote: > > > > * Ananth N Mavinakayanahalli wrote: > > > > > On Fri, Jan 29, 2010 at 08:39:07AM +0100, Ingo Molnar wrote: > > > > > > ... > > > > > > > When we merged kprobes ~10 years ago we made the (rather bad) mistake of > > > > merging a raw, opaque facility and leaving 'the rest' up to some other entity. > > > > IBM kprobes hackers vanished the day the original kprobes code went upstream > > > > and the high level entity never truly materialized in-kernel, for nearly a > > > > decade! > > > > > > I don't know what you are referring to here... Kprobes was merged in 2.6.9 > > > (~August 2004 -- less than 6 years ago). [...] > > > > Ok, 6 years then :-) > > > > > [...] Since then, we did work on ports to powerpc and s390. We implemented > > > kretprobes. We made it much scalable using RCU; we did the powerpc booster > > > to skip single-step when possible, not to mention various bug fixes over the > > > years. > > > > Except it had no real in-kernel user. > > Not that I want to rebut you Ingo, but there were in-kernel users since 2006 > (net/ipv4/tcp_probe.c) :-) i said 'real' users. That usage in tcp_probe.c was (and is) really minimal and never expanded really. > Aside, I am also glad that we have more flexibility with the perf > integration. ok, good :) Ingo -- 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/