Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756728AbZCULxl (ORCPT ); Sat, 21 Mar 2009 07:53:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752450AbZCULxb (ORCPT ); Sat, 21 Mar 2009 07:53:31 -0400 Received: from mx2.redhat.com ([66.187.237.31]:51781 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751087AbZCULxa (ORCPT ); Sat, 21 Mar 2009 07:53:30 -0400 Date: Sat, 21 Mar 2009 07:51:41 -0400 From: "Frank Ch. Eigler" To: Andrew Morton Cc: Ingo Molnar , Roland McGrath , Steven Rostedt , utrace-devel@redhat.com, linux-kernel@vger.kernel.org, Linus Torvalds , Peter Zijlstra , Thomas Gleixner Subject: Re: [PATCH 3/3] utrace-based ftrace "process" engine, v2 Message-ID: <20090321115141.GA3566@redhat.com> References: <20090321013946.890F4FC3AB@magilla.sf.frob.com> <20090321014244.9ADF1FC3AB@magilla.sf.frob.com> <20090321074301.GA19384@elte.hu> <20090321013912.ed6039c9.akpm@linux-foundation.org> <20090321091235.GA29678@elte.hu> <20090321041954.72b99e69.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090321041954.72b99e69.akpm@linux-foundation.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1686 Lines: 40 Hi - On Sat, Mar 21, 2009 at 04:19:54AM -0700, Andrew Morton wrote: > [...] > > Utrace is very much tracing material - without the ftrace plugin the > > whole utrace machinery is just something that provides a _ton_ of > > hooks to something entirely external: SystemTap mainly. > > Roland's changelogs don't mention systemtap at all afacit. > That was, umm, major information lossage. There have been many mixed messages from LKML on the topic - sometimes mentioning systemtap is forbidden, other times necessary. Sorry about that. There are several non-systemtap clients in existence or under development. You've may have heard of the ptrace cleanup, a multi-client ptrace replacement, an on-the-fly core dumper, the ftrace widget, user-space probes. All of these should have somewhat compelling non-systemtap uses, if that's an important criterion. > Actually it seems that the whole utrace-ftrace thing is a big > distraction and could/should just be omitted. This is a systemtap > feature and should be viewed as such. [...] utrace is a better way to perform user thread management than what is there now, and the utrace-ftrace widget shows how to *hook* thread events such as syscalls in a lighter weight / more managed way than the first one proposed. (That's one reason we've been participating in the ftrace discussions.) Of course it can be made to use the fine syscall pretty-printing code recently added. - 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/