Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752273AbdLXQIR (ORCPT ); Sun, 24 Dec 2017 11:08:17 -0500 Received: from shells.gnugeneration.com ([66.240.222.126]:34286 "EHLO shells.gnugeneration.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750898AbdLXQIP (ORCPT ); Sun, 24 Dec 2017 11:08:15 -0500 Date: Sun, 24 Dec 2017 08:16:01 -0800 From: vcaputo@pengaru.com To: Thomas Gleixner Cc: Pavel Machek , linux-kernel Subject: Re: thinkpad x60: sound problems in 4.15-rc1 was Re: thinkpad x60: sound problems in 4.14.0-next-20171114 Message-ID: <20171224161601.cu6kr74cfckfxkj3@shells.gnugeneration.com> References: <20171214095730.GA6150@amd> <20171219020658.qpvxx7fqvrisezs6@shells.gnugeneration.com> <20171219045415.46croaosad656d5v@shells.gnugeneration.com> <20171219231256.dpizizz55o27op3s@shells.gnugeneration.com> <20171219232212.GA5177@amd> <20171220003610.vogk3wrke47drsfw@shells.gnugeneration.com> <20171223053700.xu2fdir32e4e6cd6@shells.gnugeneration.com> <20171223203741.q4hwq6i33cjf3dyg@shells.gnugeneration.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1883 Lines: 47 On Sat, Dec 23, 2017 at 09:33:37PM +0100, Thomas Gleixner wrote: > On Sat, 23 Dec 2017, vcaputo@pengaru.com wrote: > > On Fri, Dec 22, 2017 at 09:37:01PM -0800, vcaputo@pengaru.com wrote: > > Added the following instrumentation: > > > > diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c > > index 93edc2236282..7034eda4d494 100644 > > --- a/arch/x86/kernel/apic/vector.c > > +++ b/arch/x86/kernel/apic/vector.c > > @@ -228,6 +228,9 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d, > > cpumask_and(vector_searchmask, vector_searchmask, mask); > > BUG_ON(apic->cpu_mask_to_apicid(vector_searchmask, irqdata, > > &d->cfg.dest_apicid)); > > + > > + printk("allocated vector=%i maskfirst=%i\n", d->cfg.vector, cpumask_first(vector_searchmask)); > > + > > return 0; > > } > > > > This is what I see: > > > > Upon playing song in cmus (on AC power since boot): > > Dec 22 22:26:52 iridesce kernel: allocated vector=35 maskfirst=1 > > > > Yank AC: > > Dec 22 22:27:14 iridesce kernel: allocated vector=51 maskfirst=1 > > Dec 22 22:27:15 iridesce kernel: do_IRQ: 0.35 No irq handler for vector > > > > So CPU 0 vector 35 got an interrupt when maskfirst=1 for 35 as seen in > > the added printk. > > > > It seems like the affinity changes are assuming a strict adherence to > > the CPU mask when the underlying hardware is treating it more as a hint. > > Perhaps handlers still need to be maintained on all CPUs in a given apic > > domain, regardless of what the masks are configured as, to cover these > > situations. > > That's odd. I'll have a look after the holidays. > Ok, just FYI I've reproduced it on rc5 as well. I may be offline a bit at the start of the new year, in case you've got something for me to test and I'm unresponsive. Regards, Vito Caputo