From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH] RFC: Set irq thread to RT priority on creation Date: Thu, 30 May 2013 16:07:43 +0200 (CEST) Message-ID: References: <1369915975-28797-1-git-send-email-meltedpianoman@gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: RT , Sebastian Andrzej Siewior , Steven Rostedt , LKML To: Ivo Sieben Return-path: Received: from www.linutronix.de ([62.245.132.108]:33560 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754666Ab3E3OHq (ORCPT ); Thu, 30 May 2013 10:07:46 -0400 In-Reply-To: <1369915975-28797-1-git-send-email-meltedpianoman@gmail.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Thu, 30 May 2013, Ivo Sieben wrote: > When a threaded irq handler is installed the irq thread is initially created > on normal scheduling priority. Only after the the irq thread is woken up it > sets its priority to RT_FIFO MAX_USER_RT_PRIO/2. > > This means that interrupts that occur directly after the irq handler is > installed will be handled on a normal scheduling priority instead of the > realtime priority that you would expect. Fixed this by setting the RT > priority on creation of the irq_thread. > > Signed-off-by: Ivo Sieben > --- > > RFC: > Whas there a specific reason for the irq_thread to be created on normal > scheduling and only set to RT priority when woken up? No. > This patch solves an issue for me where a device driver is expected to handle an > interrupt immediatly after irq handlers are installed and interrupts enabled. You miss to explain what kind of issue that is. Thanks, tglx