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 21:50:41 +0200 (CEST) Message-ID: References: <1369915975-28797-1-git-send-email-meltedpianoman@gmail.com> <1369925681.26799.6.camel@gandalf.local.home> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Ivo Sieben , RT , Sebastian Andrzej Siewior , LKML To: Steven Rostedt Return-path: Received: from www.linutronix.de ([62.245.132.108]:35043 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753849Ab3E3Tuo (ORCPT ); Thu, 30 May 2013 15:50:44 -0400 In-Reply-To: <1369925681.26799.6.camel@gandalf.local.home> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Thu, 30 May 2013, Steven Rostedt wrote: > On Thu, 2013-05-30 at 16:07 +0200, Thomas Gleixner wrote: > > > > 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. > > I could envision the case where the interrupt is initialized but doesn't > go off until much later. If it never ran, then it would still be in > SCHED_OTHER(), and that first interrupt could have a large delay. Nope. As Ivo explained it's about an interrupt coming in right away, i.e. before __setup_irq() reaches: if (new->thread) wake_up_process(new->thread); The ones which come much later do not have that issue as the thread code already sits in the waiting loop and already adjusted the priority. Thanks, tglx