From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753890AbYJXPDV (ORCPT ); Fri, 24 Oct 2008 11:03:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755740AbYJXPC4 (ORCPT ); Fri, 24 Oct 2008 11:02:56 -0400 Received: from mx2.redhat.com ([66.187.237.31]:41984 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755449AbYJXPCz (ORCPT ); Fri, 24 Oct 2008 11:02:55 -0400 Date: Fri, 24 Oct 2008 11:02:39 -0400 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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