From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4BB53643.2080604@domain.hid> Date: Fri, 02 Apr 2010 02:11:47 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <20100401230843.GF3755@domain.hid> <4BB53566.3010601@domain.hid> In-Reply-To: <4BB53566.3010601@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] New scheduler class List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: xenomai@xenomai.org Jan Kiszka wrote: > Andreas Glatz wrote: >> Hi Philippe, >> >> At the Xenomai Users Meeting last year I asked you if Xenomai would offer a possibility to lower the priority of certain Xenomai tasks below that of Linux. We need this feature since we have tasks in our RT application which should only run when Linux is idle (A statistics collection task which part of the RT application and hard to isolate from this application). >> > > What prevents using a borderline thread (if you need to interact with > blocking Xenomai services) with SCHED_OTHER and a Linux nice level of 19? Well, this does not really guarantee that the thread will run only when linux is idle. The thread will eat some cpu time, the nice level is not a strict priority, as you know. But in fact, I wonder why Andreas wants a new scheduling policy for xenomai, what is needed, is simply a SCHED_IDLE (maybe it exists ?!) policy for Linux. -- Gilles.