From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753822Ab1IPJlF (ORCPT ); Fri, 16 Sep 2011 05:41:05 -0400 Received: from www.linutronix.de ([62.245.132.108]:48755 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752512Ab1IPJlD (ORCPT ); Fri, 16 Sep 2011 05:41:03 -0400 Date: Fri, 16 Sep 2011 11:41:00 +0200 (CEST) From: Thomas Gleixner To: Marc Zyngier cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH 1/3] genirq: add support for per-cpu dev_id interrupts In-Reply-To: <4E7318CB.8010105@arm.com> Message-ID: References: <1316105551-17505-1-git-send-email-marc.zyngier@arm.com> <1316105551-17505-2-git-send-email-marc.zyngier@arm.com> <4E7318CB.8010105@arm.com> User-Agent: Alpine 2.02 (LFD 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, 16 Sep 2011, Marc Zyngier wrote: > On 15/09/11 23:49, Thomas Gleixner wrote: > >> + > >> + raw_spin_unlock_irqrestore(&desc->lock, flags); > >> + > >> + unregister_handler_proc(irq, action); > >> + > >> + /* Make sure it's not being used on another CPU: */ > >> + synchronize_irq(irq); > > > > That's not helping w/o making synchronize_irq() aware of the percpu > > stuff. Also there is the question whether we need the ability to > > remove such interrupts in the first place. The target users are low > > level arch interrupts not some random device drivers. > > Again, there is no need for this at the moment (the timer code runs > running forever), and this is only there for completeness. > > I'll see if I can come up with a synchronize_percpu_irq() without adding > too much bloat to irqdesc. You'd need a PROGRESS flag per cpu, which is overkill. What you can do is to check whether the percpu enabled cpumask is completely empty and return with a WARN when not. Thanks, tglx