From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751515Ab2AMFYJ (ORCPT ); Fri, 13 Jan 2012 00:24:09 -0500 Received: from e6.ny.us.ibm.com ([32.97.182.146]:34821 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750759Ab2AMFYG (ORCPT ); Fri, 13 Jan 2012 00:24:06 -0500 Date: Fri, 13 Jan 2012 10:44:48 +0530 From: Srikar Dronamraju To: Masami Hiramatsu Cc: Peter Zijlstra , Linus Torvalds , Oleg Nesterov , Ingo Molnar , Andrew Morton , LKML , Linux-mm , Andi Kleen , Christoph Hellwig , Steven Rostedt , Roland McGrath , Thomas Gleixner , Arnaldo Carvalho de Melo , Anton Arapov , Ananth N Mavinakayanahalli , Jim Keniston , Stephen Rothwell , yrl.pp-manager.tt@hitachi.com Subject: Re: [PATCH v8 3.2.0-rc5 9/9] perf: perf interface for uprobes Message-ID: <20120113051447.GD10189@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20111216122756.2085.95791.sendpatchset@srdronam.in.ibm.com> <20111216122951.2085.95511.sendpatchset@srdronam.in.ibm.com> <4F06D22D.9060906@hitachi.com> <20120109112236.GA10189@linux.vnet.ibm.com> <4F0F8F41.3060806@hitachi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <4F0F8F41.3060806@hitachi.com> User-Agent: Mutt/1.5.20 (2009-06-14) x-cbid: 12011305-1976-0000-0000-000009736B7D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > I mean that tp->module always !NULL if uprobe, then, we don't need > to change the code. (thus we can reduce the patch size :)) > Agree, the new patch that I sent does this. > > >>> + > >>> +#define DEFAULT_FUNC_FILTER "!_*" > >> > >> This is a hidden rule for users ... please remove it. > >> (or, is there any reason why we need to have it?) > >> > > > > This is to be in sync with your commit > > 3c42258c9a4db70133fa6946a275b62a16792bb5 > > I see, but that commit also provides filter option for changing > the function filter. Here, user can not change the filter rule. > > I think, currently, we don't need to filter any function by name > here, since the user obviously intends to probe given function :) Actually this was discussed in LKML here https://lkml.org/lkml/2010/7/20/5, please refer the sub-thread. Basically without this filter, the list of functions is too large including labels, weak, and local binding function which arent traced. We can make this filter settable at a later point of time. > > > > If the user provides a symbolic link, convert_name_to_addr would get the > > target executable for the given executable. This would handy if we were > > to compare existing probes registered on the same application using a > > different name (symbolic links). Since you seem to like that we register > > with the name the user has provided, I will just feed address here. > > Hmm, why do we need to compare the probe points? Of course, event-name > conflict should be solved, but I think it is acceptable that user puts > several probes on the same exec:vaddr. Since different users may want > to use it concurrently bit different ways. > The event-names themselves are generated from the probe points. There is no problem as such if two or more people use a different symlinks to create probes. I was just trying to see if we could solve the inconsitency where we warn a person if he is trying to place a probe on a existing probe but allow the same if he is trying to place a probe on a existing probe using a different symlink. This again I have changed as you suggested in the latest patches that I sent this week. -- Thanks and Regards Srikar