From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932787AbXGYPqk (ORCPT ); Wed, 25 Jul 2007 11:46:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753011AbXGYPqc (ORCPT ); Wed, 25 Jul 2007 11:46:32 -0400 Received: from smtp4-g19.free.fr ([212.27.42.30]:50196 "EHLO smtp4-g19.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751451AbXGYPqc (ORCPT ); Wed, 25 Jul 2007 11:46:32 -0400 Message-ID: <46A77054.8040203@free.fr> Date: Wed, 25 Jul 2007 17:46:28 +0200 From: John Sigler User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061108 SeaMonkey/1.0.6 MIME-Version: 1.0 To: Karsten Wiese CC: Ingo Molnar , linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Pin-pointing the root of unusual application latencies References: <469600F7.3060603@free.fr> <20070725133835.GA17616@elte.hu> <46A758B5.9070602@free.fr> <200707251728.00207.fzu@wemgehoertderstaat.de> In-Reply-To: <200707251728.00207.fzu@wemgehoertderstaat.de> 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 Karsten Wiese wrote: > John Sigler wrote: > >> Is there some form of priority inheritance? Does the IRQ handler get a >> priority boost if a high priority task is waiting for it? > > No. But that would be "nice to have". No to the first question? to the second question? or to both? :-) In kernel/futex.c does "PI" stand for Priority Inheritance? e.g. /* * Priority Inheritance state: */ struct futex_pi_state { /* * list of 'owned' pi_state instances - these have to be * cleaned up in do_exit() if the task exits prematurely: */ struct list_head list; /* * The PI object: */ struct rt_mutex pi_mutex; struct task_struct *owner; atomic_t refcount; union futex_key key; };