From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752750AbZH0Nza (ORCPT ); Thu, 27 Aug 2009 09:55:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752699AbZH0Nz3 (ORCPT ); Thu, 27 Aug 2009 09:55:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57269 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752691AbZH0Nz3 (ORCPT ); Thu, 27 Aug 2009 09:55:29 -0400 Date: Thu, 27 Aug 2009 10:55:07 -0300 From: Arnaldo Carvalho de Melo To: Jens Axboe Cc: Ingo Molnar , Li Zefan , Christoph Hellwig , rostedt@goodmis.org, fweisbec@gmail.com, acme@redhat.com, linux-kernel@vger.kernel.org Subject: Re: blktrace ftrace plugin, was Re: Receive side performance issue with multi-10-GigE and NUMA Message-ID: <20090827135507.GL5255@ghostprotocols.net> References: <20090826190435.GC10816@hmsreliant.think-freely.org> <20090826190830.GF13632@elte.hu> <20090826.123631.79533250.davem@davemloft.net> <20090826194835.GA16508@elte.hu> <20090826202344.GE10816@hmsreliant.think-freely.org> <20090826204027.GA21159@elte.hu> <20090827003047.GA30341@infradead.org> <20090827052628.GE12579@kernel.dk> <20090827091227.GB4260@elte.hu> <20090827091454.GG12579@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090827091454.GG12579@kernel.dk> X-Url: http://oops.ghostprotocols.net:81/blog User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Aug 27, 2009 at 11:14:54AM +0200, Jens Axboe escreveu: > On Thu, Aug 27 2009, Ingo Molnar wrote: > > > > * Jens Axboe wrote: > > > > > On Wed, Aug 26 2009, Christoph Hellwig wrote: > > > > On Wed, Aug 26, 2009 at 10:40:27PM +0200, Ingo Molnar wrote: > > > > > We are also converting non-trivial plugins to generic tracepoints. A > > > > > recent example are the system call tracepoints, but we also > > > > > converted blktrace and kmemtrace to generic tracepoints. > > > > > > > > On something semi-related: Any reason to keep the blktrace > > > > ftrace plugin around? I don't think there's much point in it. > > > > It only got added in 2.6.29, and all the blktrace tooling just > > > > uses the legacy ioctls. All new uses should just use the > > > > TRACE_EVENT output. > > > > > > Lets kill it. > > > > Agreed. > > > > I think we should keep the relayfs and ioctl compatibility bits > > though: blktrace has a mature user-space environment with many > > years of installed base. > > > > We could even move those bits back to block/blktrace_compat.c or so > > (after the ftrace plugin bits are removed), to make sure it's nicely > > isolated. > > > > What do you think? > > Of course, we have to retain the ioctl/relayfs interface, it's been in > use for years. Keeping those out of the other trace/ bits sounds sane. Yeah, I wonder tho if we couldn't somehow use the ring buffer infrastructure in such a way as to provide the debugfs visible interface provided by relayfs, IIRC systemtap is doing such a move too. - Arnaldo