Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753489AbbDHG2z (ORCPT ); Wed, 8 Apr 2015 02:28:55 -0400 Received: from mail-wg0-f51.google.com ([74.125.82.51]:36830 "EHLO mail-wg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751191AbbDHG2y (ORCPT ); Wed, 8 Apr 2015 02:28:54 -0400 Date: Wed, 8 Apr 2015 08:28:49 +0200 From: Ingo Molnar To: Seiichi Ikarashi Cc: Thomas Gleixner , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Peter Zijlstra Subject: Re: [PATCH] irq: Remove unnecessary warning with affinity_hint Message-ID: <20150408062849.GA23925@gmail.com> References: <5519D929.8080700@jp.fujitsu.com> <5524B2C4.50009@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5524B2C4.50009@jp.fujitsu.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1914 Lines: 55 * Seiichi Ikarashi wrote: > Hi, > > If you turn off a PCI device whose driver has set affinity_hint, > you will get warning message which does _not_ explain the reason > why it appeared from the user's point of view. > > # echo 0 > /sys/bus/pci/slots/65/power > > Apr 28 20:29:39 localhost kernel: ------------[ cut here ]------------ > Apr 28 20:29:39 localhost kernel: WARNING: at kernel/irq/manage.c:1002 __free_irq+0x22d/0x250() (Tainted: P --------------- ) > (snip) > > Users will misunderstand some problem has happened > even though he or she succeeded to turn off the device. > I suppose this warning was originally for a debug purpose > for driver developers and has incidentally been left. > > Just remove the warning is good and enough. > > Signed-off-by: Seiichi Ikarashi > > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -1335,7 +1335,7 @@ static struct irqaction *__free_irq(unsi > > #ifdef CONFIG_SMP > /* make sure affinity_hint is cleaned up */ > - if (WARN_ON_ONCE(desc->affinity_hint)) > + if (desc->affinity_hint) > desc->affinity_hint = NULL; Well, drivers that are using irq_set_affinity_hint() are expected to call: irq_set_affinity_hint(irq, NULL); to clear the affinity mask, before releasing the irq. This warning flags drivers that forgot to do that and which might thus leak a dynamically allocated CPU mask (and/or other resources). Feel free to turn the warning message into a more informative WARN() that will blame the driver that triggered it, if the stack dump into the driver wasn't a clue enough ... Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/