Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756861Ab0A2Jb7 (ORCPT ); Fri, 29 Jan 2010 04:31:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755272Ab0A2Jb5 (ORCPT ); Fri, 29 Jan 2010 04:31:57 -0500 Received: from e36.co.us.ibm.com ([32.97.110.154]:44999 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754222Ab0A2Jbx (ORCPT ); Fri, 29 Jan 2010 04:31:53 -0500 Date: Fri, 29 Jan 2010 15:01:36 +0530 From: Ananth N Mavinakayanahalli To: Ingo Molnar 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: <20100129093136.GH16920@in.ibm.com> Reply-To: ananth@in.ibm.com 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100129091116.GB10878@elte.hu> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1452 Lines: 38 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) :-) Aside, I am also glad that we have more flexibility with the perf integration. Ananth -- 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/