Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760695AbXIRQyT (ORCPT ); Tue, 18 Sep 2007 12:54:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759560AbXIRQyJ (ORCPT ); Tue, 18 Sep 2007 12:54:09 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:42645 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759573AbXIRQyI (ORCPT ); Tue, 18 Sep 2007 12:54:08 -0400 Message-ID: <46F0026F.7030102@us.ibm.com> Date: Tue, 18 Sep 2007 09:53:03 -0700 From: Vara Prasad User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: David Wilder CC: Andrew Morton , linux-kernel@vger.kernel.org, SystemTAP , Mathieu Desnoyers Subject: Re: [PATCH 0/2] A kernel tracing interface References: <46E9CB0D.2040206@us.ibm.com> <20070914174953.04b0b158.akpm@linux-foundation.org> <46EFFF9D.6090609@us.ibm.com> In-Reply-To: <46EFFF9D.6090609@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2452 Lines: 67 David Wilder wrote: > Andrew Morton wrote: > >> On Thu, 13 Sep 2007 16:43:09 -0700 >> David Wilder wrote: >> >>> These patches provide a kernel tracing interface called "trace". >>> >>> The motivation for "trace" is to: >>> - Provide a simple set of tracing primitives that will utilize the >>> high- >>> performance and low-overhead of relayfs for passing traces data from >>> kernel to user space. >>> - Provide a common user interface for managing kernel traces. >>> - Allow for binary as well as ascii trace data. >>> - Incorporate features from the systemtap runtime that are >>> useful to others. >>> >>> History- Versions of this code have been submitted for review under >>> a couple of different names. The original submission was called UTT, >>> it was later re-submitted as GTSC. Christoph Hellwig commented "The >>> code looks fine ...but the name is just dumb". Following Christoph's >>> advice, I changed the name to simply "Trace". >>> >>> This patch addresses review comments made by Christoph Hellwig and >>> Mathieu >>> Desnoyers. Changes include the addition of a mutex and synchronization >>> protecting trace state changes (using RCU) and the reduction of the >>> number of exports. >>> >>> Patches are against 2.6.23-rc4-mm1 >>> >>> Required patches: >>> 1/2 Trace code and documentation >>> 2/2 Relay reset consumed (required for trace's "rewind" feature") >>> >>> Signed-off-by: David Wilder >> >> >> Well the code looks neat and easy enough to merge. >> >> What exactly is the relationship between this and systemtap and >> kprobes and >> all the other tracing things which people are doing? >> >> > The key to the relationship is relay. Systemtap, kprobes, blktrace > ,(and others) need the fast user-kernel data hose that relay provides. > Trace is a means to simplify and standardize the use of relay. > Systemtap adopted this code some time ago in its own runtime. Moving > this code into the kernel will allow other tracers to take advantage > of the same trace primitives. Andrew, This is part of the effort by the SystemTap team to move pieces of the project that are generic to mainline. bye, Vara Prasad - 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/