From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9867 invoked by alias); 1 Feb 2008 19:44:02 -0000 Received: (qmail 9852 invoked by uid 22791); 1 Feb 2008 19:44:01 -0000 X-Spam-Status: No, hits=-1.7 required=5.0 tests=AWL,BAYES_05,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, 01 Feb 2008 19:43:39 +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 m11JhbNM012070; Fri, 1 Feb 2008 14:43:37 -0500 Received: from pobox-3.corp.redhat.com (pobox-3.corp.redhat.com [10.11.255.67]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m11JhbVo001827; Fri, 1 Feb 2008 14:43:37 -0500 Received: from touchme.toronto.redhat.com (IDENT:postfix@touchme.yyz.redhat.com [10.15.16.9]) by pobox-3.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m11JhKKc007875; Fri, 1 Feb 2008 14:43:36 -0500 Received: from ton.toronto.redhat.com (ton.yyz.redhat.com [10.15.16.15]) by touchme.toronto.redhat.com (Postfix) with ESMTP id 13D898001FF; Fri, 1 Feb 2008 14:43:03 -0500 (EST) 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 m11Jgltf017202; Fri, 1 Feb 2008 14:42:47 -0500 Received: (from fche@localhost) by ton.toronto.redhat.com (8.13.1/8.13.1/Submit) id m11JgldY017201; Fri, 1 Feb 2008 14:42:47 -0500 X-Authentication-Warning: ton.toronto.redhat.com: fche set sender to fche@redhat.com using -f To: Andrew Cagney Cc: systemtap@sourceware.org, frysk Subject: Re: my notes from the tracing workshop References: <47A34AA2.5070404__28393.9727153212$1201883893$gmane$org@redhat.com> From: fche@redhat.com (Frank Ch. Eigler) Date: Fri, 01 Feb 2008 19:44:00 -0000 In-Reply-To: <47A34AA2.5070404__28393.9727153212$1201883893$gmane$org@redhat.com> (Andrew Cagney's message of "Fri, 01 Feb 2008 11:36:50 -0500") Message-ID: User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 Mailing-List: contact frysk-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: frysk-owner@sourceware.org X-SW-Source: 2008-q1/txt/msg00048.txt.bz2 Andrew Cagney writes: > [...] > Overview Thank you! > [...] > The exceptions were SystemTAP and SensorPoint (Wind River) (and on the > edge, frysk). Both SystemTAP and SensorPoint and the same basic > approaches. SensorPoint did have a djprobe like mechanism working, > and nested(?) probes (where you could specify the call chain required > to trigger the probe - it worked by watching the functions and not by > looking at backtraces); We will approximate this with the incoming optimizations for "conditional probes". > finally the ability to replace code on live systems. I dunno when we try to address this aspect. > Finaly, the big and positive thing on probes was that the kernel > markers being accepted. [...] > > This is where SystemTAP and SensorPoint stood out (I think :-). Both > have the ability to filter events before pushing them to the recorder. > Using SystemTAP on the kernel markers should be a wicked combination. Yeah, we hope so! > [Can I assume that, when there's a marked up kernel, SystemTAP > inserts jumps instead of traps?] Indeed - or rather, the kernel marker API does this for us. We become just a client. This was what my "integration platform for probing" title line was all about - we can attach natively to multiple instrumentation systems and present them in a cohesive manner. > [...] > "DB" > There was a strong consensus that the "internal" format of the log > data needed to be a fast light weight database; two vendors were using > sqlite for instance (TPTP the eclipse tool didn't but I suspect will > shortly). [...] This seems rather wacky. If they're talking about gigabytes of trace traffic, a little wee in-memory database is a reach. If you need to do declarative querying, then you need a real database with indexes and whatnot. If you just need a big ass array, use BerkeleyDB. If you just want strongly typed flat data on disk, go XML. I wish I'd been there - perhaps my perceptions could have been falsified. > [...] What's the status of SystemTAP on the ARM? [...] I haven't run it personally, but others have (Eugene Teo for the Nokia N800). One difficulty appears to be finding a big enough ARM box to self-host the kernel module build process, or else cross-compiling and cross-running. - FChE