Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262078AbVAOBMZ (ORCPT ); Fri, 14 Jan 2005 20:12:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262103AbVAOBJI (ORCPT ); Fri, 14 Jan 2005 20:09:08 -0500 Received: from scrub.xs4all.nl ([194.109.195.176]:20673 "EHLO scrub.xs4all.nl") by vger.kernel.org with ESMTP id S262089AbVAOBGp (ORCPT ); Fri, 14 Jan 2005 20:06:45 -0500 Date: Sat, 15 Jan 2005 02:06:32 +0100 (CET) From: Roman Zippel X-X-Sender: roman@scrub.home To: Karim Yaghmour cc: Andi Kleen , Nikita Danilov , linux-kernel@vger.kernel.org, Tom Zanussi Subject: Re: 2.6.11-rc1-mm1 In-Reply-To: <41E8358A.4030908@opersys.com> Message-ID: References: <20050114002352.5a038710.akpm@osdl.org> <20050114103836.GA71397@muc.de> <41E7A7A6.3060502@opersys.com> <41E8358A.4030908@opersys.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1431 Lines: 32 Hi, On Fri, 14 Jan 2005, Karim Yaghmour wrote: > As you can see, most of this is already used in one way or another by > LTT. The only thing LTT doesn't use is the dynamic resizing, but as was > said earlier in this thread, some people actually want to have this. This doesn't mean everything has to be put into a single call. Several parameters can still be set after creation. > start_reserve, end_reserve, rchan_start_reserve: > Some subsystems, like LTT, need to be able to write some key > data at sub-buffer boundaries. This is to specify how much > space is required for said data. Why should a subsystem care about the details of the buffer management? You could move all this into the relay layer by making a relay channel an event channel. I know you want to save space, but having a magic event_struct_size array is not a good idea. If you have that much events, that a little more overhead causes problems, the tracing results won't be reliable anymore anyway. Simplicity and maintainability are far more important than saving a few bytes, the general case should be fast and simple, leave the complexity to the special cases. bye, Roman - 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/