From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279AbYI3To2 (ORCPT ); Tue, 30 Sep 2008 15:44:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754158AbYI3ToS (ORCPT ); Tue, 30 Sep 2008 15:44:18 -0400 Received: from smtp-out.google.com ([216.239.33.17]:11632 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754069AbYI3ToR (ORCPT ); Tue, 30 Sep 2008 15:44:17 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=RMFMo2mSzILM3zMKxvP6isAGTbRQX7NHscnUSobmlv4C4uVWTMxXXqVpKhUCRIVg6 LWL+QcEUkLUGPG+seS4tw== Message-ID: <33307c790809301244x40218be6of61b53104b8d7da3@mail.gmail.com> Date: Tue, 30 Sep 2008 12:44:08 -0700 From: "Martin Bligh" To: "Mathieu Desnoyers" Subject: Re: [RFC PATCH] LTTng relay buffer allocation, read, write Cc: "Steven Rostedt" , "Peter Zijlstra" , linux-kernel@vger.kernel.org, prasad@linux.vnet.ibm.com, "Linus Torvalds" , "Thomas Gleixner" , od@suse.com, "Frank Ch. Eigler" , "Andrew Morton" , hch@lst.de, "David Wilder" , "Tom Zanussi" In-Reply-To: <20080930183531.GA20670@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080927134012.GA11930@Krystal> <20080929155004.GA11029@Krystal> <1222709445.23876.70.camel@twins.programming.kicks-ass.net> <20080929203124.GA23070@Krystal> <33307c790809301022q2821ecc7iabf41eb513707e0c@mail.gmail.com> <33307c790809301023v1b0755fbsab1bbfa9bfaad58@mail.gmail.com> <20080930181436.GA19690@Krystal> <20080930183531.GA20670@Krystal> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > You are actually using them to put redundant information that could be > encoded differently and thus save 4 bits per event records, more or less > what will be needed by most tracers (15 IDs, 1 reserved for an extended > ID field). You have 15 event types that are useful with no data payload at all? > So the fact that you use them does not mean they are really required, > and I don't think such duplicated information actually makes things more > solid. Maybe just more obscure ? This is all over 1 bit of information, right? Since you need at least 1 for the timestamp stuff.