From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753495AbYIYSwx (ORCPT ); Thu, 25 Sep 2008 14:52:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754789AbYIYSwk (ORCPT ); Thu, 25 Sep 2008 14:52:40 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:57033 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753255AbYIYSwi (ORCPT ); Thu, 25 Sep 2008 14:52:38 -0400 Message-Id: <20080925185154.230259579@goodmis.org> User-Agent: quilt/0.46-1 Date: Thu, 25 Sep 2008 14:51:54 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Andrew Morton , prasad@linux.vnet.ibm.com, Linus Torvalds , Mathieu Desnoyers , "Frank Ch. Eigler" , David Wilder , hch@lst.de, Martin Bligh , Christoph Hellwig Subject: [RFC PATCH 0/2 v3] Unified trace buffer Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ NOTE function comments have not been updated. Comments within the code has.] This version I change the event header to what Peter Zijlstra requested. The buffer alignment is now 4 from 8. The minimum event is 8 bytes. The event header is now: struct event_header { u32 type:2, len:3, time_delta:27; u32 array[]; }; The length of the record is determined as: if (data size > 28 bytes) lenght = event->array[0] + sizeof(event_header); else length = event->len << 4 + sizeof(event_header); For data if (date size > 28 bytes) data = &event->array[0]; else data = &event->array[1]; There are now only 4 internal data types: 0 - Padding 1 - time extent 2 - time stamp 3 - data This is for internal buffer management only. Other event types should be pushed to a higher layer, and stored in the data field. The timing is basically the same as v2 but I added a reader side ring_buffer_normalize_time_stamp() operation. As a test, I mult the timestamp to -1, in both set and normalize operations. Whether this actually tests anything is another story ;-) I actually like this header and structure the best. And this may be what I start working on for real. So please speak up on this one. I'm going to take a break from this and start doing my real work. This will let others soak it up for a bit. -- Steve