From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751667AbaGKHYj (ORCPT ); Fri, 11 Jul 2014 03:24:39 -0400 Received: from www.linutronix.de ([62.245.132.108]:53363 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751341AbaGKHYi (ORCPT ); Fri, 11 Jul 2014 03:24:38 -0400 Date: Fri, 11 Jul 2014 09:24:33 +0200 (CEST) From: Thomas Gleixner To: Ben Hutchings cc: LKML , stable-rt@vger.kernel.org Subject: Re: Interrupt randomness in 3.14.10-rt In-Reply-To: <1405045492.26540.67.camel@deadeye.wl.decadent.org.uk> Message-ID: References: <1405045492.26540.67.camel@deadeye.wl.decadent.org.uk> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 11 Jul 2014, Ben Hutchings wrote: > I noticed this change between 3.14.3-rt5 and 3.14.10-rt7: > > --- debian/patches/features/all/rt/random-make-it-work-on-rt.patch (revision 21522) > +++ debian/patches/features/all/rt/random-make-it-work-on-rt.patch (working copy) > [...] > ---- a/kernel/irq/manage.c > -+++ b/kernel/irq/manage.c > -@@ -942,6 +942,12 @@ static int irq_thread(void *data) > - if (action_ret == IRQ_HANDLED) > - atomic_inc(&desc->threads_handled); > - > -+#ifdef CONFIG_PREEMPT_RT_FULL > -+ migrate_disable(); > -+ add_interrupt_randomness(action->irq, 0, > -+ desc->random_ip ^ (unsigned long) action); > -+ migrate_enable(); > -+#endif > - wake_threads_waitq(desc); > - } > - > > (I.e. old patch included these additions, new patch doesn't.) > > Evidently this was made in the announced 3.14.10-rt6, not -rt7. Was it > intentional? Now irq_desc::random_ip is set but never used. Hmm, how did I lose that one? Thanks for spotting it! I'll pick it up for rt8 tglx