Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752292AbZFJJsa (ORCPT ); Wed, 10 Jun 2009 05:48:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751019AbZFJJsV (ORCPT ); Wed, 10 Jun 2009 05:48:21 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:56666 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbZFJJsU (ORCPT ); Wed, 10 Jun 2009 05:48:20 -0400 Date: Wed, 10 Jun 2009 05:48:19 -0400 From: Christoph Hellwig To: Frederic Weisbecker Cc: Steven Rostedt , linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Minchan Kim , Mel Gorman , Christoph Hellwig , Rik van Riel , Pekka Enberg , Peter Zijlstra , Theodore Tso , Mathieu Desnoyers , Lai Jiangshan , Zhaolei , KOSAKI Motohiro , Jason Baron , Jiaying Zhang Subject: Re: [RFC PATCH 2/5] tracing/events: nicer print format for parsing Message-ID: <20090610094819.GA25527@infradead.org> References: <20090609014534.790466803@goodmis.org> <20090609014746.481457542@goodmis.org> <20090609192159.GD6057@nowhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090609192159.GD6057@nowhere> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1393 Lines: 27 On Tue, Jun 09, 2009 at 09:22:01PM +0200, Frederic Weisbecker wrote: > But I wonder if the above new language is not breaking the charm > of the TRACE_EVENT(), which charm is that it's easy to implement (hopefully). > > Everyone knows the printk formats. And I guess this new thing is easy and > quick to learn. But because it's a new unknown language, the TRACE_EVENT > will become less readable, less reachable for newcomers in TRACE_EVENT. I must also say I don't particularly like it. printk is nice and easy an everybody knows it, but it's not quite flexible enough as we might have to do all kinds of conversions on the reader side. What might be a better idea is to just have C function pointer for output conversions that could be put into the a file in debugfs and used by the binary trace buffer reader. Or maybe not as we would pull in too many depenencies. I think we should go with the printk solution for 2.6.31 and use the full development cycle for 2.6.32 to come up with something better. As soon as a couple of large subsystems use the even tracer we also have a broader base examples to see how new syntax works on them. -- 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/