Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946195AbXBPS3T (ORCPT ); Fri, 16 Feb 2007 13:29:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946196AbXBPS3T (ORCPT ); Fri, 16 Feb 2007 13:29:19 -0500 Received: from gamma2.look.ca ([207.136.100.4]:58796 "EHLO gatekeeper.look.ca" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1946195AbXBPS3S (ORCPT ); Fri, 16 Feb 2007 13:29:18 -0500 Date: Fri, 16 Feb 2007 13:30:14 -0500 To: "Frank Ch. Eigler" Cc: linux-kernel@vger.kernel.org Message-ID: <20070216183014.GD6425@infidigm.net> References: <20070216013024.GA32287@infidigm.net> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i From: Jeff Muizelaar X-SA-Exim-Mail-From: jeff@infidigm.net Subject: Re: Using sched_clock for mmio-trace Content-Type: text/plain; charset=us-ascii X-SA-Exim-Version: 3.1 (built Tue Feb 24 05:09:27 GMT 2004) X-SA-Exim-Scanned: Yes Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1785 Lines: 42 On Fri, Feb 16, 2007 at 11:30:56AM -0500, Frank Ch. Eigler wrote: > Jeff Muizelaar writes: > > > I've built a tool with the goal of logging mmio writes and reads by > > device drivers. See http://nouveau.freedesktop.org/wiki/MmioTrace. > > FWIW, this is exactly a type of add-on trace patch that could be > mooted by adoption of the ltt/systemtap "marker" facility. With it, > you would not need so much code (e.g. no new user-space tools at all, > reuse of common tracing buffer logic, permanently placed hooks) and > would probably get more utility. Is there more information on this "marker" facility? e.g. what is a marker? Are they just like tracepoints? > > [...] The question is, what [timer] api should I be using? I need > > something that can be called from inside interrupt handlers, and > > obviously the more accurate and the lower the overhead the better. > > We in systemtap land have the same problem, and so far made do with > slightly postprocessed per-cpu TSC values. Thanks, I'll have a look at systemtap does. It's the stuff src/runtime/time.c right? Also, you might want to move this stuff from the README to someplace more prominent on the systemtap website. It's nice not to have to dig far to get the source... Download systemtap sources snapshot or from CVS: ftp://sources.redhat.com/pub/systemtap/snapshots/ (or) cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/systemtap login # enter "anoncvs" as the password cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/systemtap co src -Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/