Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753301AbaJQH3z (ORCPT ); Fri, 17 Oct 2014 03:29:55 -0400 Received: from www.linutronix.de ([62.245.132.108]:45743 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbaJQH3y (ORCPT ); Fri, 17 Oct 2014 03:29:54 -0400 Date: Fri, 17 Oct 2014 09:29:50 +0200 (CEST) From: Thomas Gleixner To: Lina Iyer cc: khilman@linaro.org, ulf.hansson@linaro.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, rjw@rjwysocki.net, daniel.lezcano@linaro.org Subject: Re: [PATCH v3 3/4] irq: Allow multiple clients to register for irq affinity notification In-Reply-To: <20141010151106.GC2128@ilina-mac.qualcomm.com> Message-ID: References: <1409170479-29955-1-git-send-email-lina.iyer@linaro.org> <1409170479-29955-4-git-send-email-lina.iyer@linaro.org> <20140902184305.GB91995@ilina-mac.local> <20140925155027.GG1004@ilina-mac.local> <20141010151106.GC2128@ilina-mac.qualcomm.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) 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, 10 Oct 2014, Lina Iyer wrote: > On Wed, Oct 08 2014 at 09:03 -0600, Thomas Gleixner wrote: > > On Thu, 25 Sep 2014, Lina Iyer wrote: > > > > How would a general "keep track of the targets of all interrupts in > > > > the system" mechanism make use of this? > > > Sorry, I do not understand your question. > > > PM QoS is only interested in the IRQs specified in the QoS request. If > > > there are no requests that need to be associated with an IRQ, then PM > > > QoS will not register for an affinity change notification. > > > > Right, and I really hate the whole per irq notifier. It's a rats nest > > of life time issues and other problems. > > > > It also does not tell you whether an irq is disabled, reenabled or > > removed, which will change the qos constraints as well unless you > > plaster all drivers with updates to qos for those cases. > > > > So what about adding a qos field to irq_data itself, have a function > > to update it and let the irq core keep track of the per cpu irq > > relevant qos constraints and provide an evaluation function or a > > notifier for the PM/idle code? > > If that isnt intrusive in the IRQ core, then we can make it work for PM > QoS. The issue that I am concerned is that, it might result in back and > forth between IRQ and PM QoS frameworks. If that doesnt happen, then we > are good with this approach. I can't tell that upfront, but I think it's worth to explore it. Thanks, tglx -- 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/