Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755017AbZCUVT6 (ORCPT ); Sat, 21 Mar 2009 17:19:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752110AbZCUVTt (ORCPT ); Sat, 21 Mar 2009 17:19:49 -0400 Received: from mx2.redhat.com ([66.187.237.31]:52212 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751007AbZCUVTt (ORCPT ); Sat, 21 Mar 2009 17:19:49 -0400 Message-ID: <49C559DE.5020404@redhat.com> Date: Sat, 21 Mar 2009 17:19:26 -0400 From: Masami Hiramatsu User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Andrew Morton CC: Ingo Molnar , Steven Rostedt , Ananth N Mavinakayanahalli , Frederic Weisbecker , LKML , systemtap-ml Subject: Re: [RFC][PATCH -tip 0/5 V2] tracing: kprobe-based event tracer References: <49C443E1.6070400@redhat.com> <20090321041316.562e7a0f.akpm@linux-foundation.org> In-Reply-To: <20090321041316.562e7a0f.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2081 Lines: 58 Andrew Morton wrote: > On Fri, 20 Mar 2009 21:33:21 -0400 Masami Hiramatsu wrote: > >> echo /debug/tracing/trace > > Should be cat, I assume? Ah, yes, thanks! >> # tracer: nop >> # >> # TASK-PID CPU# TIMESTAMP FUNCTION >> # | | | | | >> <...>-2376 [001] 262.389131: do_sys_open: @do_sys_open+0 0xffffff9c 0x98db83e 0x8880 0x0 >> <...>-2376 [001] 262.391166: sys_open: <-do_sys_open+0 0x5 0xc06e8ebb >> <...>-2376 [001] 264.384876: do_sys_open: @do_sys_open+0 0xffffff9c 0x98db83e 0x8880 0x0 >> <...>-2376 [001] 264.386880: sys_open: <-do_sys_open+0 0x5 0xc06e8ebb >> <...>-2084 [001] 265.380330: do_sys_open: @do_sys_open+0 0xffffff9c 0x804be3e 0x0 0x1b6 >> <...>-2084 [001] 265.380399: sys_open: <-do_sys_open+0 0x3 0xc06e8ebb > > Well... this is cool and all that, but nowhere near as useful as kgdb! > Its main competition however will be plain old printk. kgdb or other debugger might be able to use this tracer, but this will provide just a low-level infrastructure. > Do we really honestly think that this feature will be sufficiently useful > to a sufficiently large number of kernel developers as to warrant > inclusion? No, I think it's just a starting point. > Perhaps a bit more thought about some more complex use cases would help. > > And given that the users of this (and other tracing features) are general > kernel developers rather than tracing (or kprobes) developers, it would be > nice to get some feedback and even testing/usage results from those people. > ie: everyone else. I hope so, Thank you! -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: mhiramat@redhat.com -- 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/