From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761248AbYDXQNt (ORCPT ); Thu, 24 Apr 2008 12:13:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754203AbYDXQNl (ORCPT ); Thu, 24 Apr 2008 12:13:41 -0400 Received: from tomts22.bellnexxia.net ([209.226.175.184]:47429 "EHLO tomts22-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754013AbYDXQNk (ORCPT ); Thu, 24 Apr 2008 12:13:40 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArEEAGtOEEhMROPA/2dsb2JhbACBUqte Date: Thu, 24 Apr 2008 12:13:37 -0400 From: Mathieu Desnoyers To: Pavel Emelyanov Cc: akpm@linux-foundation.org, Ingo Molnar , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [patch 37/37] LTTng instrumentation net Message-ID: <20080424161337.GA22874@Krystal> References: <20080424150324.802695381@polymtl.ca> <20080424151408.991424268@polymtl.ca> <4810ACB4.501@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <4810ACB4.501@openvz.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 12:09:42 up 55 days, 12:20, 6 users, load average: 0.72, 1.04, 1.24 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 * Pavel Emelyanov (xemul@openvz.org) wrote: > Mathieu Desnoyers wrote: > > Network core events. > > > > Added markers : > > > > net_del_ifa_ipv4 > > net_dev_receive > > net_dev_xmit > > net_insert_ifa_ipv4 > > net_socket_call > > net_socket_create > > net_socket_recvmsg > > net_socket_sendmsg > > Network "core" events are not limited with the above calls. > True. This is by no mean an exhaustive list of network events. It just happens to be the ones which has been useful to LTT/LTTng users for the past ~10 years. > Besides, real "core" events already sent notifications about themselves. > Why do we need additional hooks? > I doubt the current notification hooks have a performance impact as small as the proposed markers. Which notification mechanism do you refer to ? It could be interesting to put markers in there instead. The goal behind this is to feed information to a general purpose tracer like lttng, a scripting mechanism like systemtap or a special-purpose tracer like ftrace. I think that the most important instrumentation in this patchset is the xmit/recv of a packet at the device level. The net_socket_* instrumentation could eventually be replaced by an architecture specfic system call parameters instrumentation. Mathieu > > Signed-off-by: Mathieu Desnoyers > > CC: netdev@vger.kernel.org > > --- > > net/core/dev.c | 6 ++++++ > > net/ipv4/devinet.c | 6 ++++++ > > net/socket.c | 19 +++++++++++++++++++ > > 3 files changed, 31 insertions(+) > -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68