From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17216 invoked by alias); 20 Oct 2006 00:15:40 -0000 Received: (qmail 17209 invoked by uid 22791); 20 Oct 2006 00:15:40 -0000 X-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00,SPF_PASS X-Spam-Check-By: sourceware.org Received: from skunk.mtbrook.bozemanpass.com (HELO skunk.mtbrook.bozemanpass.com) (69.145.82.195) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 20 Oct 2006 00:15:37 +0000 Received: from [69.145.82.253] (unknown [69.145.82.253]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by skunk.mtbrook.bozemanpass.com (Postfix) with ESMTP id 08F1C558289; Thu, 19 Oct 2006 17:15:35 -0700 (PDT) Message-ID: <45381525.7000100@boreham.org> Date: Fri, 20 Oct 2006 00:15:00 -0000 From: David Boreham User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Frank Ch. Eigler" CC: SystemTap Subject: Re: user mode backtrace References: <4537E44C.6040604@boreham.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2006-q4/txt/msg00206.txt.bz2 > > >We don't yet have a good answer to user-space stuff in general. We >may adopt a mixture of two approaches: one where the compiled >systemtap probes get some extract of backtrace-enabling unwind >information for selected user-space programs and libraries (so the >backtrace processing can be done instantly right there); and another >one where the probe may snapshot only an approximation (say a vector >of probable PCs from the thread's stack frame), and rely on a >user-space helper to correct/complete it for output later, off-line. > > Given the choice I'd prefer the latter because it'd be less intrusive.