From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757955Ab0IGQrp (ORCPT ); Tue, 7 Sep 2010 12:47:45 -0400 Received: from mail.openrapids.net ([64.15.138.104]:37113 "EHLO blackscsi.openrapids.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757123Ab0IGQrn (ORCPT ); Tue, 7 Sep 2010 12:47:43 -0400 Date: Tue, 7 Sep 2010 12:47:40 -0400 From: Mathieu Desnoyers To: Srikar Dronamraju Cc: Christoph Hellwig , Peter Zijlstra , Ingo Molnar , Steven Rostedt , Arnaldo Carvalho de Melo , Linus Torvalds , Masami Hiramatsu , Oleg Nesterov , Mark Wielaard , Andrew Morton , Naren A Devaiah , Jim Keniston , Frederic Weisbecker , "Frank Ch. Eigler" , Ananth N Mavinakayanahalli , LKML , "Paul E. McKenney" , Srivatsa Vaddagiri Subject: Re: [PATCHv11 2.6.36-rc2-tip 5/15] 5: uprobes: Uprobes (un)registration and exception handling. Message-ID: <20100907164740.GA17491@Krystal> References: <20100825134117.5447.55209.sendpatchset@localhost6.localdomain6> <20100825134224.5447.89998.sendpatchset@localhost6.localdomain6> <1283377414.2059.1729.camel@laptop> <20100903164219.GB1904@linux.vnet.ibm.com> <1283534349.2050.297.camel@laptop> <20100906174642.GG14891@linux.vnet.ibm.com> <20100906204042.GA19815@infradead.org> <20100907120258.GK14891@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100907120258.GK14891@linux.vnet.ibm.com> X-Editor: vi X-Info: http://www.efficios.com X-Operating-System: Linux/2.6.26-2-686 (i686) X-Uptime: 12:44:34 up 227 days, 19:21, 4 users, load average: 0.11, 0.11, 0.08 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Srikar Dronamraju (srikar@linux.vnet.ibm.com) wrote: > > On Mon, Sep 06, 2010 at 11:16:42PM +0530, Srikar Dronamraju wrote: [...] > > > > Which btw, brings up two more issues, one in uprobes and one in perf. > > For one even in userspace I think the dynamic probes will really just > > be the tip of the iceberg and we'll get more bang for the buck from > > static traces, which is something that's no supported in uprobes yet. > > As a start supporting the dtrace-style sdt.h header would be a great > > help, and then we can decide if we need somthing even better on top. > > Yes, Static tracing using dtrace style sdt.h is a cool thing to do. > Already SystemTap has this facility. However I think its probably > better done at perf user interface level. We currently have this feature in UST. We're adding "markers" into the applications, and a UST daemon talks with an in-process library helper thread to enable/disable markers and control tracing over unix sockets. We're currently in the process of moving from markers to the TRACE_EVENT()+tracepoints infrastructure. Thanks, Mathieu > > The way I look at it is perf probe decodes the static markers and asks > uprobes to place probepoints over there. > Do you see a different approach? If yes can you tell what you were > looking at? -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com