From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7646 invoked by alias); 7 Jul 2008 14:36:54 -0000 Received: (qmail 7637 invoked by uid 0); 7 Jul 2008 14:36:54 -0000 Resent-Message-ID: <20080707143654.7636.qmail@sourceware.org> Received: (qmail 2492 invoked by uid 22791); 6 Jul 2008 12:43:51 -0000 X-Spam-Status: No, hits=-2.6 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from verein.lst.de (HELO verein.lst.de) (213.95.11.210) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 06 Jul 2008 12:43:16 +0000 Received: from verein.lst.de (localhost [127.0.0.1]) by verein.lst.de (8.12.3/8.12.3/Debian-7.1) with ESMTP id m66CamNW009502 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Sun, 6 Jul 2008 14:36:48 +0200 Received: (from hch@localhost) by verein.lst.de (8.12.3/8.12.3/Debian-6.6) id m66CalW8009500; Sun, 6 Jul 2008 14:36:47 +0200 Date: Mon, 07 Jul 2008 14:36:00 -0000 From: Christoph Hellwig To: "K.Prasad" Cc: Christoph Hellwig , Peter Zijlstra , Theodore Tso , ksummit-2008-discuss@lists.linux-foundation.org, Roland McGrath , systemtap@sources.redhat.com Subject: Re: [Ksummit-2008-discuss] DTrace Message-ID: <20080706123647.GB9265@lst.de> References: <20080630201031.GF7988@mit.edu> <20080630204219.GA6631@redhat.com> <20080701024140.GB28143@mit.edu> <20080701070746.C6DAD15420E@magilla.localdomain> <20080701101507.GB22717@mit.edu> <20080701200632.6790A1541F5@magilla.localdomain> <20080701231327.GA5829@mit.edu> <1215251049.6320.15.camel@lappy.programming.kicks-ass.net> <20080705100536.GA18534@lst.de> <20080705180432.GA6077@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080705180432.GA6077@in.ibm.com> User-Agent: Mutt/1.3.28i X-Spam-Score: 0 () X-Scanned-By: MIMEDefang 2.39 X-Reason: blocked: hch@lst.de 213.95.11.210 -> systemtap@sources.redhat.com (global body, SA: score=-2.6 required=5.0 tests=PRESCANNED,AWL,BAYES_00) X-Sender: hch@lst.de Resent-From: root@sourceware.org Resent-Date: Mon, 7 Jul 2008 14:36:54 +0000 Resent-To: systemtap@sources.redhat.com 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-q3/txt/msg00066.txt.bz2 On Sat, Jul 05, 2008 at 11:34:32PM +0530, K.Prasad wrote: > > You can write probes in plain C, in fact I do this all the time. what's > > missing is a nice and easy to use channel to get the traces to userspace > > and interpret them, and helper for poking at kernel data structures. > > > As you might be aware the "trace" interface which is part of the -mm > tree was meant to satisfy such needs. >From the interface POV it's a step in the right direction. But to make adhoc kprobe tracing viable for anyone but hardcore kernel hackers we basically want a /debug/trace always availble so that the traces just need to relay_printk() on it. We also want some helpers to encode complex strucures. See the current printk on steroids discussion on lkml which would be pretty helpful for it.