From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1864 invoked by alias); 24 Oct 2008 15:03:40 -0000 Received: (qmail 1849 invoked by uid 22791); 24 Oct 2008 15:03:39 -0000 X-Spam-Status: No, hits=-2.2 required=5.0 tests=AWL,BAYES_00,KAM_MX,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 24 Oct 2008 15:02:58 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id m9OF2h1N001183 for ; Fri, 24 Oct 2008 11:02:43 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m9OF2gHj008981 for ; Fri, 24 Oct 2008 11:02:42 -0400 Received: from ton.toronto.redhat.com (ton.yyz.redhat.com [10.15.16.15]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id m9OF2d1w001275; Fri, 24 Oct 2008 11:02:42 -0400 Received: from ton.toronto.redhat.com (localhost.localdomain [127.0.0.1]) by ton.toronto.redhat.com (8.13.1/8.13.1) with ESMTP id m9OF2dIZ030759; Fri, 24 Oct 2008 11:02:39 -0400 Received: (from fche@localhost) by ton.toronto.redhat.com (8.13.1/8.13.1/Submit) id m9OF2dPP030758; Fri, 24 Oct 2008 11:02:39 -0400 Date: Fri, 24 Oct 2008 15:03:00 -0000 From: "Frank Ch. Eigler" To: Steven Rostedt Cc: =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Ingo Molnar , linux-kernel@vger.kernel.org, systemtap@sources.redhat.com Subject: Re: [PATCH 5/5] tracing/ftrace: Introduce the big kernel lock tracer Message-ID: <20081024150239.GB20768@redhat.com> References: <48F10B0B.406@gmail.com> <20081024143744.GA20768@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2008-q4/txt/msg00201.txt.bz2 Hi - On Fri, Oct 24, 2008 at 10:47:36AM -0400, Steven Rostedt wrote: > [...] > > > I would rather prefer to use an API that provides functions/objects > > > for most common scripting languages. > > > > That is an interesting idea. One possible problem is that the final > > complete script "program" needs to be translated to something that can > > run quickly and safely inside the kernel. Full python or perl runtime > > + libraries would have been almost certainly unbearable. > > Why can't the userspace application convert the script to something > easy that the kernel can handle? That's what we do with the systemtap script, where kernel "handling" consists of "running the machine code". > But have the user application interface be very simple, and perhaps > even use perl or python. perl and python are pretty big procedural languages, and are not easily compiled down to compact & quickly executed machine code. (I take it no one is suggesting including a perl or python VM in the kernel.) Plus, debugger-flavoured event-handling programming style would not look nearly as compact in perl/python as in systemtap, which is small and domain-specific. - FChE