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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 97D3FC4338F for ; Wed, 28 Jul 2021 10:41:10 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5806260F02 for ; Wed, 28 Jul 2021 10:41:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5806260F02 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:References: CC:To:Subject:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6MpM5YBSnLHqQmnm1ko9oOQqUSoh7Wj/2pYDZo7oNLc=; b=0uWPZxh7qR7SrI2OBmtNdmCmhQ DKtE2n9YZuEgM0JLLiGRZvr/ShyykkqR5i+FFqD4u3qewBuQi8IubiofekeCs6zyYz6GckHjnN3Z3 GfDUqqqIa9wpsYGE7oUvYTTnwHObUZg6QhxQH2c+Wg4mFRPyLe+xbHpo5uMdKD5w88EOtYs6JpIIL 71zTglt5NbJvXLxDbLsGI0ayX4QCSU6MdbvWZSgYJ3Yy34pVsIvRFvnpMmI0SAHvF75WZDuRQftrs uv3VfxXrvElD1mDq4TnbDpJnNwN3jsB3jwCmWt1FlvTfUjLLYFP3fv96SkDWGr0UhZyXy+xY50Fou IbJypexQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8gxi-000Qat-Ql; Wed, 28 Jul 2021 10:38:54 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8gxb-000QYo-IT; Wed, 28 Jul 2021 10:38:49 +0000 Received: from fraeml702-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GZVFj46N2z6L9kY; Wed, 28 Jul 2021 18:26:49 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml702-chm.china.huawei.com (10.206.15.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 28 Jul 2021 12:38:41 +0200 Received: from [10.47.27.80] (10.47.27.80) 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 15.1.2176.2; Wed, 28 Jul 2021 11:38:41 +0100 From: John Garry Subject: Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node To: Ming Lei CC: Robin Murphy , , , , "Will Deacon" , References: <74537f9c-af5f-cd84-60ab-49ca6220310e@huawei.com> <9c929985-4fcb-e65d-0265-34c820b770ea@huawei.com> <0adbe03b-ce26-e4d3-3425-d967bc436ef5@arm.com> <6ceab844-465f-3bf3-1809-5df1f1dbbc5c@huawei.com> Message-ID: Date: Wed, 28 Jul 2021 11:38:18 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Originating-IP: [10.47.27.80] X-ClientProxiedBy: lhreml706-chm.china.huawei.com (10.201.108.55) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210728_033847_828104_B1B9C941 X-CRM114-Status: GOOD ( 16.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 28/07/2021 02:32, Ming Lei wrote: > On Mon, Jul 26, 2021 at 3:51 PM John Garry wrote: >> On 23/07/2021 11:21, Ming Lei wrote: >>>> Thanks, I was also going to suggest the latter, since it's what >>>> arm_smmu_cmdq_issue_cmdlist() does with IRQs masked that should be most >>>> indicative of where the slowness most likely stems from. >>> The improvement from 'iommu.strict=0' is very small: >>> >> Have you tried turning off the IOMMU to ensure that this is really just >> an IOMMU problem? >> >> You can try setting CONFIG_ARM_SMMU_V3=n in the defconfig or passing >> cmdline param iommu.passthrough=1 to bypass the the SMMU (equivalent to >> disabling for kernel drivers). > Bypassing SMMU via iommu.passthrough=1 basically doesn't make a difference > on this issue. A ~90% throughput drop still seems to me to be too high to be a software issue. More so since I don't see similar on my system. And that throughput drop does not lead to a total CPU usage drop, from the fio log. Do you know if anyone has run memory benchmark tests on this board to find out NUMA effect? I think lmbench or stream could be used for this. Testing network performance in an equivalent fashion to storage could also be an idea. Thanks, John > > And from fio log, submission latency is good, but completion latency > is pretty bad, > and maybe it is something that writing to PCI memory isn't committed to HW in > time? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel