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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 751F3C43603 for ; Fri, 20 Dec 2019 15:38:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F4B421655 for ; Fri, 20 Dec 2019 15:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727491AbfLTPib (ORCPT ); Fri, 20 Dec 2019 10:38:31 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2212 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726808AbfLTPib (ORCPT ); Fri, 20 Dec 2019 10:38:31 -0500 Received: from lhreml702-cah.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id 5D4369A1CA2D908B3AD6; Fri, 20 Dec 2019 15:38:29 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by lhreml702-cah.china.huawei.com (10.201.108.43) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 20 Dec 2019 15:38:28 +0000 Received: from [127.0.0.1] (10.210.166.34) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1713.5; Fri, 20 Dec 2019 15:38:27 +0000 Subject: Re: [PATCH RFC 1/1] genirq: Make threaded handler use irq affinity for managed interrupt To: Marc Zyngier CC: Ming Lei , , "chenxiang (M)" , , , , , , , , 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> <0ad37515-c22d-6857-65a2-cc28256a8afa@huawei.com> <20191212223805.GA24463@ming.t460p> <20191213131822.GA19876@ming.t460p> <20191214135641.5a817512@why> <7db89b97-1b9e-8dd1-684a-3eef1b1af244@huawei.com> <50d9ba606e1e3ee1665a0328ffac67ac@www.loen.fr> <68058fd28c939b8e065524715494de95@www.loen.fr> <687cbcc4-89d9-63ea-a246-ce2abaae501a@huawei.com> <0fd543f8ffd90f90deb691aea1c275b4@www.loen.fr> From: John Garry Message-ID: Date: Fri, 20 Dec 2019 15:38:24 +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: <0fd543f8ffd90f90deb691aea1c275b4@www.loen.fr> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.210.166.34] X-ClientProxiedBy: lhreml703-chm.china.huawei.com (10.201.108.52) 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 >> We've got some more results and it looks promising. >> >> So with your patch we get a performance boost of 3180.1K -> 3294.9K >> IOPS in the D06 SAS env. Then when we change the driver to use >> threaded interrupt handler (mainline currently uses tasklet), we get a >> boost again up to 3415K IOPS. >> >> Now this is essentially the same figure we had with using threaded >> handler + the gen irq change in spreading the handler CPU affinity. We >> did also test your patch + gen irq change and got a performance drop, >> to 3347K IOPS. >> >> So tentatively I'd say your patch may be all we need. > > OK. > >> FYI, here is how the effective affinity is looking for both SAS >> controllers with your patch: >> >> 74:02.0 >> irq 81, cpu list 24-29, effective list 24 cq >> irq 82, cpu list 30-35, effective list 30 cq > > Cool. > > [...] > >> As for your patch itself, I'm still concerned of possible regressions >> if we don't apply this effective interrupt affinity spread policy to >> only managed interrupts. > > I'll try and revise that as I post the patch, probably at some point > between now and Christmas. I still think we should find a way to > address this for the D05 SAS driver though, maybe by managing the > affinity yourself in the driver. But this requires experimentation. I've already done something experimental for the driver to manage the affinity, and performance is generally much better: https://github.com/hisilicon/kernel-dev/commit/e15bd404ed1086fed44da34ed3bd37a8433688a7 But I still think it's wise to only consider managed interrupts for now. > >> JFYI, about NVMe CPU lockup issue, there are 2 works on going here: >> >> https://lore.kernel.org/linux-nvme/20191209175622.1964-1-kbusch@kernel.org/T/#t >> >> >> https://lore.kernel.org/linux-block/20191218071942.22336-1-ming.lei@redhat.com/T/#t >> > > I've also managed to trigger some of them now that I have access to > a decent box with nvme storage. I only have 2x NVMe SSDs when this occurs - I should not be hitting this... Out of curiosity, have you tried > with the SMMU disabled? I'm wondering whether we hit some livelock > condition on unmapping buffers... No, but I can give it a try. Doing that should lower the CPU usage, though, so maybe masks the issue - probably not. Much appreciated, John