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=-5.3 required=3.0 tests=BAYES_00, 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 C2B74C432BE for ; Tue, 10 Aug 2021 09:37:35 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 748A961073 for ; Tue, 10 Aug 2021 09:37:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 748A961073 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 37B5D404C7; Tue, 10 Aug 2021 09:37:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cKkmdCKKc3ri; Tue, 10 Aug 2021 09:37:31 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTPS id 081F3404B8; Tue, 10 Aug 2021 09:37:30 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id D30A3C0010; Tue, 10 Aug 2021 09:37:30 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 66C2FC000E for ; Tue, 10 Aug 2021 09:37:29 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 4F86B834F1 for ; Tue, 10 Aug 2021 09:37:29 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tP4rjwJkfHql for ; Tue, 10 Aug 2021 09:37:28 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id 09F68834EF for ; Tue, 10 Aug 2021 09:37:27 +0000 (UTC) Received: from fraeml740-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GkSX12Jrkz6C9JD; Tue, 10 Aug 2021 17:36:49 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml740-chm.china.huawei.com (10.206.15.221) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Tue, 10 Aug 2021 11:37:22 +0200 Received: from [10.47.80.4] (10.47.80.4) 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 15.1.2176.2; Tue, 10 Aug 2021 10:37:21 +0100 Subject: Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node To: Ming Lei References: <9c929985-4fcb-e65d-0265-34c820b770ea@huawei.com> <0adbe03b-ce26-e4d3-3425-d967bc436ef5@arm.com> <6ceab844-465f-3bf3-1809-5df1f1dbbc5c@huawei.com> From: John Garry Message-ID: Date: Tue, 10 Aug 2021 10:36:47 +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: [10.47.80.4] X-ClientProxiedBy: lhreml712-chm.china.huawei.com (10.201.108.63) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Cc: Robin Murphy , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, iommu@lists.linux-foundation.org, Will Deacon , linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 28/07/2021 16:17, Ming Lei wrote: >>>> 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. > https://lore.kernel.org/lkml/YOhbc5C47IzC893B@T590/ Hi Ming, Out of curiosity, did you investigate this topic any further? And you also asked about my results earlier: On 22/07/2021 16:54, Ming Lei wrote: >> [ 52.035895] nvme 0000:81:00.0: Adding to iommu group 5 >> [ 52.047732] nvme nvme0: pci function 0000:81:00.0 >> [ 52.067216] nvme nvme0: 22/0/2 default/read/poll queues >> [ 52.087318] nvme0n1: p1 >> >> So I get these results: >> cpu0 335K >> cpu32 346K >> cpu64 300K >> cpu96 300K >> >> So still not massive changes. > In your last email, the results are the following with irq mode io_uring: > > cpu0 497K > cpu4 307K > cpu32 566K > cpu64 488K > cpu96 508K > > So looks you get much worse result with real io_polling? > Would the expectation be that at least I get the same performance with io_polling here? Anything else to try which you can suggest to investigate this lower performance? Thanks, John _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu