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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 9593FC43603 for ; Wed, 11 Dec 2019 09:41:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71D91214D8 for ; Wed, 11 Dec 2019 09:41:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728719AbfLKJlJ (ORCPT ); Wed, 11 Dec 2019 04:41:09 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2179 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727318AbfLKJlJ (ORCPT ); Wed, 11 Dec 2019 04:41:09 -0500 Received: from lhreml709-cah.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id 0B0E3A29A83A9E5777E6; Wed, 11 Dec 2019 09:41:07 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by lhreml709-cah.china.huawei.com (10.201.108.32) with Microsoft SMTP Server (TLS) id 14.3.408.0; Wed, 11 Dec 2019 09:41:06 +0000 Received: from [127.0.0.1] (10.202.226.46) 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 15.1.1713.5; Wed, 11 Dec 2019 09:41:06 +0000 Subject: Re: [PATCH RFC 1/1] genirq: Make threaded handler use irq affinity for managed interrupt To: Marc Zyngier CC: Ming Lei , "tglx@linutronix.de" , "chenxiang (M)" , "bigeasy@linutronix.de" , "linux-kernel@vger.kernel.org" , "hare@suse.com" , "hch@lst.de" , "axboe@kernel.dk" , "bvanassche@acm.org" , "peterz@infradead.org" , "mingo@redhat.com" References: <1575642904-58295-1-git-send-email-john.garry@huawei.com> <1575642904-58295-2-git-send-email-john.garry@huawei.com> <20191207080335.GA6077@ming.t460p> <78a10958-fdc9-0576-0c39-6079b9749d39@huawei.com> <20191210014335.GA25022@ming.t460p> <28424a58-1159-c3f9-1efb-f1366993afcf@huawei.com> <048746c22898849d28985c0f65cf2c2a@www.loen.fr> <6e513d25d8b0c6b95d37a64df0c27b78@www.loen.fr> <06d1e2ff-9ec7-2262-25a0-4503cb204b0b@huawei.com> <5caa8414415ab35e74662ac0a30bb4ac@www.loen.fr> From: John Garry Message-ID: Date: Wed, 11 Dec 2019 09:41:05 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <5caa8414415ab35e74662ac0a30bb4ac@www.loen.fr> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.46] X-ClientProxiedBy: lhreml728-chm.china.huawei.com (10.201.108.79) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/12/2019 18:32, Marc Zyngier wrote: >>>> The ITS code will make the lowest online CPU in the affinity mask >>>> the >>>> target CPU for the interrupt, which may result in some CPUs >>>> handling >>>> so many interrupts. >>> If what you want is for the*default* affinity to be spread around, >>> that should be achieved pretty easily. Let me have a think about how >>> to do that. >> Cool, I anticipate that it should help my case. >> >> I can also seek out some NVMe cards to see how it would help a more >> "generic" scenario. > Can you give the following a go? It probably has all kind of warts on > top of the quality debug information, but I managed to get my D05 and > a couple of guests to boot with it. It will probably eat your data, > so use caution!;-) > Hi Marc, Ok, we'll give it a spin. Thanks, John > Thanks, > > M. > > diff --git a/drivers/irqchip/irq-gic-v3-its.c > b/drivers/irqchip/irq-gic-v3-its.c > index e05673bcd52b..301ee3bc0602 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -177,6 +177,8 @@ static DEFINE_IDA(its_vpeid_ida);