From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-15?Q?Martin_D=E4umler?= Subject: Re: Priority Inheritance per se? Date: Tue, 14 Sep 2010 13:12:13 +0200 Message-ID: <4C8F588D.2080308@cs.tu-chemnitz.de> References: <4C89D4DF.9060109@cs.tu-chemnitz.de> <4C8F46B1.1010804@disco.unimib.it> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE To: linux-rt-users@vger.kernel.org Return-path: Received: from jack.hrz.tu-chemnitz.de ([134.109.132.46]:48472 "EHLO jack.hrz.tu-chemnitz.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752062Ab0INLMP (ORCPT ); Tue, 14 Sep 2010 07:12:15 -0400 Received: from adelaide.informatik.tu-chemnitz.de ([134.109.192.66]) by jack.hrz.tu-chemnitz.de with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1OvTQs-0007kx-39 for linux-rt-users@vger.kernel.org; Tue, 14 Sep 2010 13:12:14 +0200 In-Reply-To: <4C8F46B1.1010804@disco.unimib.it> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Sergio Ruocco wrote: > before really deciding for the use of PI, you may want to read what > Victor Yodaiken had to say: > > http://www.yodaiken.com/papers-and-talks/ > Against priority inheritance, Victor Yodaiken. September 23, 2004 > http://www.yodaiken.com/papers/inherit.pdf > > Here is a general Linux RT workshop report, with some comments on PI: > http://lwn.net/Articles/354690/ Hi Sergio, thanks for that reading. I (hope to) know which drawbacks and shortcomings priority inheritance has. Before I can make a decision about using an RT_PREEMPT patched Linux, I want to know if the RT_PREEMPT-patch introduces priority inheritance automatically, that is, without using any locks? =46or example (from my opening post): Imagine a hypothetical case: a high RT-priority (60) task triggers a blocking system call which triggers a device driver whose ISR is a kernel thread with RT-priority 49. So, a medium RT-priority (55) task is able block the high RT-priority task, isn't it? With kind regards, Martin D=E4umler -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html