From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFE02C433EF for ; Wed, 9 Mar 2022 10:21:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229742AbiCIKWH (ORCPT ); Wed, 9 Mar 2022 05:22:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229492AbiCIKWG (ORCPT ); Wed, 9 Mar 2022 05:22:06 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDF6216BF92 for ; Wed, 9 Mar 2022 02:21:03 -0800 (PST) Received: from fraeml707-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KD7W60dx0z6802V; Wed, 9 Mar 2022 18:20:34 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml707-chm.china.huawei.com (10.206.15.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 9 Mar 2022 11:21:01 +0100 Received: from [10.47.81.176] (10.47.81.176) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 9 Mar 2022 10:21:00 +0000 Message-ID: <70b15802-b8b1-301e-00f2-39e299114b02@huawei.com> Date: Wed, 9 Mar 2022 10:20:57 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH] genirq/msi: Shutdown managed interrupts with unsatifiable affinities To: Marc Zyngier , CC: Thomas Gleixner , David Decotigny , References: <20220307190625.254426-1-maz@kernel.org> From: John Garry In-Reply-To: <20220307190625.254426-1-maz@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.81.176] X-ClientProxiedBy: lhreml726-chm.china.huawei.com (10.201.108.77) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + On 07/03/2022 19:06, Marc Zyngier wrote: > When booting with maxcpus=, interrupt controllers > such as the GICv3 ITS may not be able to satisfy the affinity of > some managed interrupts, as some of the HW resources are simply > not available. > > In order to deal with this, do not try to activate such interrupt > if there is no online CPU capable of handling it. Instead, place > it in shutdown state. Once a capable CPU shows up, it will be > activated. > > Reported-by: John Garry > Reported-by: David Decotigny > Signed-off-by: Marc Zyngier Tested-by: John Garry > --- JFYI, I could not recreate the same crash reported in the original thread for "nohz_full=5-127 isolcpus=nohz,domain,managed_irq,5-127 maxcpus=1". Here's just showing what I set via cmdline: estuary:/$ dmesg | grep -i hz [ 0.000000] Kernel command line: BOOT_IMAGE=/john/Image rdinit=/init console=ttyS0,115200 no_console_suspend nvme.use_threaded_interrupts=0 iommu.strict=0 acpi=force earlycon=pl011,mmio32,0x602b0000 nohz_full=5-127 isolcpus=nohz,domain,managed_irq,5-127 maxcpus=1 [ 0.000000] NO_HZ: Full dynticks CPUs: 5-127. [ 0.000000] arch_timer: cp15 timer(s) running at 100.00MHz (phys). [ 0.000000] sched_clock: 57 bits at 100MHz, resolution 10ns, wraps every 4398046511100ns [ 15.314258] sbsa-gwdt sbsa-gwdt.0: Initialized with 10s timeout @ 100000000 Hz, action=0 And for the kernel build: $ more .config | grep NO_HZ CONFIG_NO_HZ_COMMON=y # CONFIG_NO_HZ_IDLE is not set CONFIG_NO_HZ_FULL=y # CONFIG_NO_HZ is not set $ Thanks, John > kernel/irq/msi.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c > index 2bdfce5edafd..aa84ce84c2ec 100644 > --- a/kernel/irq/msi.c > +++ b/kernel/irq/msi.c > @@ -818,6 +818,18 @@ static int msi_init_virq(struct irq_domain *domain, int virq, unsigned int vflag > irqd_clr_can_reserve(irqd); > if (vflags & VIRQ_NOMASK_QUIRK) > irqd_set_msi_nomask_quirk(irqd); > + > + /* > + * If the interrupt is managed but no CPU is available > + * to service it, shut it down until better times. > + */ > + if ((vflags & VIRQ_ACTIVATE) && > + irqd_affinity_is_managed(irqd) && > + !cpumask_intersects(irq_data_get_affinity_mask(irqd), > + cpu_online_mask)) { > + irqd_set_managed_shutdown(irqd); > + return 0; > + } > } > > if (!(vflags & VIRQ_ACTIVATE))