From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752677AbeFFBnb (ORCPT ); Tue, 5 Jun 2018 21:43:31 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:57179 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751977AbeFFBna (ORCPT ); Tue, 5 Jun 2018 21:43:30 -0400 Subject: Re: [PATCH] irqchip/gic-v3-its: fix ITS queue timeout To: Julien Thierry , References: <1528180225-16144-1-git-send-email-yangyingliang@huawei.com> <834fde1b-5ae0-afc6-283f-2a470757e54a@arm.com> CC: , From: Yang Yingliang Message-ID: <5B173C27.30401@huawei.com> Date: Wed, 6 Jun 2018 09:43:03 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <834fde1b-5ae0-afc6-283f-2a470757e54a@arm.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.19.219] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Julien On 2018/6/5 18:16, Julien Thierry wrote: > Hi Yang, > > On 05/06/18 07:30, Yang Yingliang wrote: >> When the kernel booted with maxcpus=x, 'x' is smaller >> than actual cpu numbers, the TAs of offline cpus won't >> be set to its->collection. >> >> If LPI is bind to offline cpu, sync cmd will use zero TA, >> it leads to ITS queue timeout. Fix this by choosing a >> online cpu, if there is no online cpu in cpu_mask. >> >> Signed-off-by: Yang Yingliang >> --- >> drivers/irqchip/irq-gic-v3-its.c | 9 +++++++-- >> 1 file changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/irqchip/irq-gic-v3-its.c >> b/drivers/irqchip/irq-gic-v3-its.c >> index 5416f2b..edd92a9 100644 >> --- a/drivers/irqchip/irq-gic-v3-its.c >> +++ b/drivers/irqchip/irq-gic-v3-its.c >> @@ -2309,7 +2309,9 @@ static int its_irq_domain_activate(struct >> irq_domain *domain, >> cpu_mask = cpumask_of_node(its_dev->its->numa_node); >> /* Bind the LPI to the first possible CPU */ >> - cpu = cpumask_first(cpu_mask); >> + cpu = cpumask_first_and(cpu_mask, cpu_online_mask); >> + if (!cpu_online(cpu)) > > Testing for cpu being online here feels a bit redundant. > > Since cpu is online if the cpumask_first_and returns a valid cpu, I > think you could replace this test with: > > if (cpu >= nr_cpu_ids) Yes, I used wrong check here, according to comment of cpumask_first_and, this func will returns >= nr_cpu_ids if no cpus set in both. I'll send v2 later. > >> + cpu = cpumask_first(cpu_online_mask); >> its_dev->event_map.col_map[event] = cpu; >> irq_data_update_effective_affinity(d, cpumask_of(cpu)); >> @@ -2466,7 +2468,10 @@ static int its_vpe_set_affinity(struct >> irq_data *d, >> bool force) >> { >> struct its_vpe *vpe = irq_data_get_irq_chip_data(d); >> - int cpu = cpumask_first(mask_val); >> + int cpu = cpumask_first_and(mask_val, cpu_online_mask); >> + >> + if (!cpu_online(cpu)) > > Same thing here. > >> + cpu = cpumask_first(cpu_online_mask); >> /* >> * Changing affinity is mega expensive, so let's be as lazy as >> > > Cheers, > Thanks, Yang