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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CC21C43387 for ; Tue, 8 Jan 2019 14:16:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6912A20850 for ; Tue, 8 Jan 2019 14:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728379AbfAHOQi (ORCPT ); Tue, 8 Jan 2019 09:16:38 -0500 Received: from foss.arm.com ([217.140.101.70]:52954 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727484AbfAHOQh (ORCPT ); Tue, 8 Jan 2019 09:16:37 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3455780D; Tue, 8 Jan 2019 06:16:37 -0800 (PST) Received: from [10.1.196.62] (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 445BE3F5D4; Tue, 8 Jan 2019 06:16:36 -0800 (PST) Subject: Re: [PATCH] ARM: irq: Add IRQ_SET_MASK_OK_DONE handling in migrate_one_irq() To: Dietmar Eggemann , linux-arm-kernel@lists.infradead.org Cc: Russell King - ARM Linux , Sudeep Holla , linux-kernel@vger.kernel.org References: <20190108135805.5535-1-dietmar.eggemann@arm.com> From: Marc Zyngier Openpgp: preference=signencrypt Autocrypt: addr=marc.zyngier@arm.com; prefer-encrypt=mutual; keydata= mQINBE6Jf0UBEADLCxpix34Ch3kQKA9SNlVQroj9aHAEzzl0+V8jrvT9a9GkK+FjBOIQz4KE g+3p+lqgJH4NfwPm9H5I5e3wa+Scz9wAqWLTT772Rqb6hf6kx0kKd0P2jGv79qXSmwru28vJ t9NNsmIhEYwS5eTfCbsZZDCnR31J6qxozsDHpCGLHlYym/VbC199Uq/pN5gH+5JHZyhyZiNW ozUCjMqC4eNW42nYVKZQfbj/k4W9xFfudFaFEhAf/Vb1r6F05eBP1uopuzNkAN7vqS8XcgQH qXI357YC4ToCbmqLue4HK9+2mtf7MTdHZYGZ939OfTlOGuxFW+bhtPQzsHiW7eNe0ew0+LaL 3wdNzT5abPBscqXWVGsZWCAzBmrZato+Pd2bSCDPLInZV0j+rjt7MWiSxEAEowue3IcZA++7 ifTDIscQdpeKT8hcL+9eHLgoSDH62SlubO/y8bB1hV8JjLW/jQpLnae0oz25h39ij4ijcp8N t5slf5DNRi1NLz5+iaaLg4gaM3ywVK2VEKdBTg+JTg3dfrb3DH7ctTQquyKun9IVY8AsxMc6 lxl4HxrpLX7HgF10685GG5fFla7R1RUnW5svgQhz6YVU33yJjk5lIIrrxKI/wLlhn066mtu1 DoD9TEAjwOmpa6ofV6rHeBPehUwMZEsLqlKfLsl0PpsJwov8TQARAQABtCNNYXJjIFp5bmdp ZXIgPG1hcmMuenluZ2llckBhcm0uY29tPokCOwQTAQIAJQIbAwYLCQgHAwIGFQgCCQoLBBYC AwECHgECF4AFAk6NvYYCGQEACgkQI9DQutE9ekObww/+NcUATWXOcnoPflpYG43GZ0XjQLng LQFjBZL+CJV5+1XMDfz4ATH37cR+8gMO1UwmWPv5tOMKLHhw6uLxGG4upPAm0qxjRA/SE3LC 22kBjWiSMrkQgv5FDcwdhAcj8A+gKgcXBeyXsGBXLjo5UQOGvPTQXcqNXB9A3ZZN9vS6QUYN TXFjnUnzCJd+PVI/4jORz9EUVw1q/+kZgmA8/GhfPH3xNetTGLyJCJcQ86acom2liLZZX4+1 6Hda2x3hxpoQo7pTu+XA2YC4XyUstNDYIsE4F4NVHGi88a3N8yWE+Z7cBI2HjGvpfNxZnmKX 6bws6RQ4LHDPhy0yzWFowJXGTqM/e79c1UeqOVxKGFF3VhJJu1nMlh+5hnW4glXOoy/WmDEM UMbl9KbJUfo+GgIQGMp8mwgW0vK4HrSmevlDeMcrLdfbbFbcZLNeFFBn6KqxFZaTd+LpylIH bOPN6fy1Dxf7UZscogYw5Pt0JscgpciuO3DAZo3eXz6ffj2NrWchnbj+SpPBiH4srfFmHY+Y LBemIIOmSqIsjoSRjNEZeEObkshDVG5NncJzbAQY+V3Q3yo9og/8ZiaulVWDbcpKyUpzt7pv cdnY3baDE8ate/cymFP5jGJK++QCeA6u6JzBp7HnKbngqWa6g8qDSjPXBPCLmmRWbc5j0lvA 6ilrF8m5Ag0ETol/RQEQAM/2pdLYCWmf3rtIiP8Wj5NwyjSL6/UrChXtoX9wlY8a4h3EX6E3 64snIJVMLbyr4bwdmPKULlny7T/R8dx/mCOWu/DztrVNQiXWOTKJnd/2iQblBT+W5W8ep/nS w3qUIckKwKdplQtzSKeE+PJ+GMS+DoNDDkcrVjUnsoCEr0aK3cO6g5hLGu8IBbC1CJYSpple VVb/sADnWF3SfUvJ/l4K8Uk4B4+X90KpA7U9MhvDTCy5mJGaTsFqDLpnqp/yqaT2P7kyMG2E w+eqtVIqwwweZA0S+tuqput5xdNAcsj2PugVx9tlw/LJo39nh8NrMxAhv5aQ+JJ2I8UTiHLX QvoC0Yc/jZX/JRB5r4x4IhK34Mv5TiH/gFfZbwxd287Y1jOaD9lhnke1SX5MXF7eCT3cgyB+ hgSu42w+2xYl3+rzIhQqxXhaP232t/b3ilJO00ZZ19d4KICGcakeiL6ZBtD8TrtkRiewI3v0 o8rUBWtjcDRgg3tWx/PcJvZnw1twbmRdaNvsvnlapD2Y9Js3woRLIjSAGOijwzFXSJyC2HU1 AAuR9uo4/QkeIrQVHIxP7TJZdJ9sGEWdeGPzzPlKLHwIX2HzfbdtPejPSXm5LJ026qdtJHgz BAb3NygZG6BH6EC1NPDQ6O53EXorXS1tsSAgp5ZDSFEBklpRVT3E0NrDABEBAAGJAh8EGAEC AAkFAk6Jf0UCGwwACgkQI9DQutE9ekMLBQ//U+Mt9DtFpzMCIHFPE9nNlsCm75j22lNiw6mX mx3cUA3pl+uRGQr/zQC5inQNtjFUmwGkHqrAw+SmG5gsgnM4pSdYvraWaCWOZCQCx1lpaCOl MotrNcwMJTJLQGc4BjJyOeSH59HQDitKfKMu/yjRhzT8CXhys6R0kYMrEN0tbe1cFOJkxSbV 0GgRTDF4PKyLT+RncoKxQe8lGxuk5614aRpBQa0LPafkirwqkUtxsPnarkPUEfkBlnIhAR8L kmneYLu0AvbWjfJCUH7qfpyS/FRrQCoBq9QIEcf2v1f0AIpA27f9KCEv5MZSHXGCdNcbjKw1 39YxYZhmXaHFKDSZIC29YhQJeXWlfDEDq6nIhvurZy3mSh2OMQgaIoFexPCsBBOclH8QUtMk a3jW/qYyrV+qUq9Wf3SKPrXf7B3xB332jFCETbyZQXqmowV+2b3rJFRWn5hK5B+xwvuxKyGq qDOGjof2dKl2zBIxbFgOclV7wqCVkhxSJi/QaOj2zBqSNPXga5DWtX3ekRnJLa1+ijXxmdjz hApihi08gwvP5G9fNGKQyRETePEtEAWt0b7dOqMzYBYGRVr7uS4uT6WP7fzOwAJC4lU7ZYWZ yVshCa0IvTtp1085RtT3qhh9mobkcZ+7cQOY+Tx2RGXS9WeOh2jZjdoWUv6CevXNQyOUXMM= Organization: ARM Ltd Message-ID: <9288fdeb-8eb1-28ca-f950-ccf36d63688a@arm.com> Date: Tue, 8 Jan 2019 14:16:34 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20190108135805.5535-1-dietmar.eggemann@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dietmar, On 08/01/2019 13:58, Dietmar Eggemann wrote: > Arm TC2 (multi_v7_defconfig plus CONFIG_ARM_BIG_LITTLE_CPUFREQ=y and > CONFIG_ARM_VEXPRESS_SPC_CPUFREQ=y) fails hotplug stress tests. > > This issue was tracked down to a missing copy of the new affinity > cpumask of the vexpress-spc interrupt into struct > irq_common_data.affinity when the interrupt is migrated in > migrate_one_irq(). > > Commit 0407daceedfe ("irqchip/gic: Return IRQ_SET_MASK_OK_DONE in the > set_affinity method") changed the return value of the irq_set_affinity() > function of the GIC from IRQ_SET_MASK_OK to IRQ_SET_MASK_OK_DONE. > > In migrate_one_irq() if the current irq affinity mask and the cpu > online mask do not share any CPU, the affinity mask is set to the cpu > online mask. In this case (ret == true) and when the irq chip > function irq_set_affinity() returns successfully (IRQ_SET_MASK_OK), > struct irq_common_data.affinity should also be updated. > > Add IRQ_SET_MASK_OK_DONE next to IRQ_SET_MASK_OK when checking that the > irq chip function irq_set_affinity() returns successfully. > > Commit 2cb625478f8c ("genirq: Add IRQ_SET_MASK_OK_DONE to support > stacked irqchip") only added IRQ_SET_MASK_OK_DONE handling to > irq_do_set_affinity() in the irq core and not to the Arm32 irq code. > > Signed-off-by: Dietmar Eggemann > --- > > The hotplug issue on Arm TC2 happens because the vexpress-spc interrupt > (irq=22) is affine to CPU0. This occurs since it is setup early when the > cpu_online_mask is still 0. > But the problem with the missing copy of the affinity mask should occur > with every interrupt which is forced to migrate. > > With additional debug in irq_setup_affinity(): > > [0.000619] irq_setup_affinity(): irq=17 mask=0 cpu_online_mask=0 set=0-4 > [0.007065] irq_setup_affinity(): irq=22 mask=0 cpu_online_mask=0 set=0-4 > [3.372907] irq_setup_affinity(): irq=47 mask=0-4 cpu_online_mask=0-4 > set=0-4 > > cat /proc/interrupts > CPU0 CPU1 CPU2 CPU3 CPU4 > 22: 316 0 0 0 0 GIC-0 127 > Level vexpress-spc > > cat /proc/irq/22/smp_affinity_list > 0 > > arch/arm/kernel/irq.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c > index 9908dacf9229..ddb828b0235b 100644 > --- a/arch/arm/kernel/irq.c > +++ b/arch/arm/kernel/irq.c > @@ -117,6 +117,7 @@ static bool migrate_one_irq(struct irq_desc *desc) > const struct cpumask *affinity = irq_data_get_affinity_mask(d); > struct irq_chip *c; > bool ret = false; > + int ret2; > > /* > * If this is a per-CPU interrupt, or the affinity does not > @@ -131,9 +132,14 @@ static bool migrate_one_irq(struct irq_desc *desc) > } > > c = irq_data_get_irq_chip(d); > - if (!c->irq_set_affinity) > + if (!c->irq_set_affinity) { > pr_debug("IRQ%u: unable to set affinity\n", d->irq); > - else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret) > + return ret; > + } > + > + ret2 = c->irq_set_affinity(d, affinity, false); > + > + if ((ret2 == IRQ_SET_MASK_OK || ret2 == IRQ_SET_MASK_OK_DONE) && ret) > cpumask_copy(irq_data_get_affinity_mask(d), affinity); > > return ret; > On the arm64 side, we've solved the exact same issue by getting rid of this code and using the generic implementation. See 217d453d473c5 ("arm64: fix a migrating irq bug when hotplug cpu"), which uses irq_migrate_all_off_this_cpu instead. I'm not sure there is much value in not using the core code in this case. Thanks, M. -- Jazz is not dead. It just smells funny...