Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750801AbWIOTCR (ORCPT ); Fri, 15 Sep 2006 15:02:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750839AbWIOTCR (ORCPT ); Fri, 15 Sep 2006 15:02:17 -0400 Received: from nz-out-0102.google.com ([64.233.162.198]:33371 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1750801AbWIOTCQ (ORCPT ); Fri, 15 Sep 2006 15:02:16 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:user-agent:mime-version:to:subject:content-type:content-transfer-encoding; b=iKflg1hg8DDz6PIPxz/wSrmj581Gk/QCzTucD8ef0GiJME2GYDTABgG9bhTF3jmRpROmgSlV/e7IafNLAHSztYPZYzelBbLPrGuotDhFLXcx8qO302u+4pHxUhvgGZW4x2Wc8g8Ml51H3MkvgSIwA+ty0mdj05bSP9tRwU+OOMY= Message-ID: <450AF8D6.8090208@gmail.com> Date: Fri, 15 Sep 2006 13:02:46 -0600 From: Jim Cromie User-Agent: Thunderbird 1.5.0.7 (X11/20060909) MIME-Version: 1.0 To: Linux kernel Subject: [RFC-patch] Doc/lockdep-design: explain display of {state-bits} Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1504 Lines: 47 Please offer corrections / wording improvements as appropriate. In particular, the ".+-? " table could be more illuminating - I lack the knowledge to make the right inferences.. (or just take it, and run with it ;-) Signed-off-by: Jim Cromie --- doc-touches/Documentation/lockdep-design.txt~ 2006-09-14 11:49:47.000000000 -0600 +++ doc-touches/Documentation/lockdep-design.txt 2006-09-15 12:46:34.000000000 -0600 @@ -36,6 +36,28 @@ - 'ever used' [ == !unused ] +When mutex rules are violated, these 4 state bits are presented in the +mutex error messages, inside curlies. A contrived example: + + modprobe/2287 is trying to acquire lock: + (&sio_locks[i].lock){--..}, at: [] mutex_lock+0x21/0x24 + + but task is already holding lock: + (&sio_locks[i].lock){--..}, at: [] mutex_lock+0x21/0x24 + + +The bit position indicates hardirq, softirq, hardirq-read, +softirq-read respectively, and the character displayed in each +indicates: + + '.' used + '+' used in irqs + '-' enabled in irqs + '?' used and enabled (bits 3,4) + +Unused mutexes cannot be part of the cause of an error. + + Single-lock state rules: ------------------------ - 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/