From mboxrd@z Thu Jan 1 00:00:00 1970 From: Carsten Emde Subject: Re: Operation not permitted / pthread_setschedparam Date: Sat, 04 Oct 2014 12:49:34 +0200 Message-ID: <542FD0BE.10508@osadl.org> References: <542A88A8.7060800@steinhoff.de> <542BACF1.3090405@steinhoff.de> <542D0689.8050602@steinhoff.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: rt-users To: Armin Steinhoff , Patrik Lundquist Return-path: Received: from toro.web-alm.net ([62.245.132.31]:51893 "EHLO toro.web-alm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750973AbaJDL2r (ORCPT ); Sat, 4 Oct 2014 07:28:47 -0400 In-Reply-To: <542D0689.8050602@steinhoff.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Armin, > [..] But there are some sideeffects to other running > processes/threads related to their assigned priorities. Here is the > priority assignment after a fresh boot: ps -elf -> > Prio-After-OS-Restart.txt attached > > If the app "demo_mn_console" has started its first RT thread, a lot > of other processes/threads are jumping to the highest RT priority > 99!! Please have a look to: ps -elf -> Prio-after-app-start.txt > > Do we have a problem with the RT kernel ? Or is simply the ps > utility broken ? Let me try to summarize your observations and suspicions: 1. After booting your RT kernel, everything works as expected. 2. The ps utility works as expected. 3. There are no bug reports that the RT kernel autonomously and at random fiddles around with task priorities. 4. There are no bug reports that the ps utility - one of the most frequently used utilities - suddenly may start to display erroneous priority numbers. 5. At a given time, you start your application that apparently modifies task priorities *in some way*. 6. Shortly afterwards you are observing that other not intended tasks changed their priority as well. 7. Your first suspicion is that we may have a problem with the RT kernel. 8. And your second suspicion is that the ps utility is broken. Doesn't come another suspicion to mind? -Carsten.