From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753231AbYI3DqT (ORCPT ); Mon, 29 Sep 2008 23:46:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751482AbYI3DqI (ORCPT ); Mon, 29 Sep 2008 23:46:08 -0400 Received: from tomts16.bellnexxia.net ([209.226.175.4]:54568 "EHLO tomts16-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751264AbYI3DqH (ORCPT ); Mon, 29 Sep 2008 23:46:07 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AuYEAHQ44UhMQWq+/2dsb2JhbACBZLobgWc Date: Mon, 29 Sep 2008 23:46:03 -0400 From: Mathieu Desnoyers To: Steven Rostedt Cc: LKML , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Andrew Morton , prasad@linux.vnet.ibm.com, Linus Torvalds , "Frank Ch. Eigler" , David Wilder , hch@lst.de, Martin Bligh , Christoph Hellwig , Masami Hiramatsu , Steven Rostedt , Arnaldo Carvalho de Melo Subject: Re: [PATCH v10 Golden] Unified trace buffer Message-ID: <20080930034603.GA13801@Krystal> References: <20080929233539.GA31143@Krystal> <20080930000307.GA2929@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 23:42:57 up 117 days, 8:23, 10 users, load average: 1.88, 2.21, 1.42 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt (rostedt@goodmis.org) wrote: > > On Mon, 29 Sep 2008, Mathieu Desnoyers wrote: > > > > > > Thanks! I must have been lucky some how not to trigger this :-/ > > > > > > > My guess is that you never free your buffers in your test cases. I don't > > know if it was expected; probably not if your code is built into the > > kernel. > > Actually my resize does free the buffers and I did test this. I probably > never ran the trace when testing the freeing which means those pointers > could have luckily not have been changed. > > -- Steve > I also got some corruption of the offset field in the struct page I use. I think it might be related to the fact that I don't set the PG_private bit (slob does set it when the page is in its free pages list). However, given I'd like to pass the buffer pages to disk I/O and for network socket and still keep the ability to re-use it when the I/O has been performed, I wonder where I should put my struct list_head list; /* linked list of buf pages */ size_t offset; /* page offset in the buffer */ fields ? Any ideas ? They are currently in : struct buf_page { union { struct { unsigned long flags; /* mandatory */ atomic_t _count; /* mandatory */ union { /* mandatory */ atomic_t _mapcount; struct { u16 inuse; u16 objects; }; }; struct list_head list; /* linked list of buf pages */ size_t offset; /* page offset in the buffer */ }; struct page page; }; }; Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68