Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753606Ab0ALWQu (ORCPT ); Tue, 12 Jan 2010 17:16:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752445Ab0ALWQt (ORCPT ); Tue, 12 Jan 2010 17:16:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:27087 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751566Ab0ALWQs (ORCPT ); Tue, 12 Jan 2010 17:16:48 -0500 Date: Tue, 12 Jan 2010 17:15:54 -0500 From: "Frank Ch. Eigler" To: Masami Hiramatsu Cc: Frederic Weisbecker , Srikar Dronamraju , Steven Rostedt , Ingo Molnar , Arnaldo Carvalho de Melo , Peter Zijlstra , Ananth N Mavinakayanahalli , utrace-devel , Jim Keniston , Maneesh Soni , Mark Wielaard , LKML Subject: Re: [RFC] [PATCH 7/7] Ftrace plugin for Uprobes Message-ID: <20100112221554.GI4822@redhat.com> References: <20100111122521.22050.3654.sendpatchset@srikar.in.ibm.com> <20100111122608.22050.94088.sendpatchset@srikar.in.ibm.com> <20100112045454.GJ5243@nowhere> <4B4CF0F4.3020706@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B4CF0F4.3020706@redhat.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1531 Lines: 36 Hi - > > As you might expect, in systemtap we've had to figure out this area > > some time ago. We use another utrace consumer called "task finder" [...] > > So, could you tell us how the task-finder works and is implemented? The code may be found at runtime/task_finder* in the systemtap sources. There is a simple interest-registration structure/API that identifies processes / shared libraries of interest, and a set of callbacks to be invoked when said processes/shared libraries are mapped or unmapped. It is implemented in terms of utrace callbacks for process/thread lifetime monitoring, and utrace syscall callbacks for tracking shared library segments being mapped and unmapped. http://sourceware.org/git/?p=systemtap.git;a=tree;f=runtime > I think we'd better clarify what functions are required for uprobes > and pmu, and I think we may be able to re-implement improved pmu on > utrace. I don't see any collision between pmu / perf / utrace, so nothing is really "required" for them or simple usage of uprobes. If you wish to track dynamic process/shared-library lifetimes, then you need extra code somewhere to respond to those changes. Layering this dynamic capability seems like the natural way to go, and is easily done with utrace and/or tracepoints. - FChE -- 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/