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=-15.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,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 2A6BCC63793 for ; Thu, 22 Jul 2021 11:12:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 907FD61244 for ; Thu, 22 Jul 2021 11:12:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231742AbhGVKbk (ORCPT ); Thu, 22 Jul 2021 06:31:40 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3449 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231627AbhGVKbi (ORCPT ); Thu, 22 Jul 2021 06:31:38 -0400 Received: from fraeml734-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GVqHV2mDDz6H7l3; Thu, 22 Jul 2021 19:00:38 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml734-chm.china.huawei.com (10.206.15.215) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Thu, 22 Jul 2021 13:12:11 +0200 Received: from [10.47.26.161] (10.47.26.161) 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; Thu, 22 Jul 2021 12:12:11 +0100 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: <23e7956b-f3b5-b585-3c18-724165994051@arm.com> <74537f9c-af5f-cd84-60ab-49ca6220310e@huawei.com> <9c929985-4fcb-e65d-0265-34c820b770ea@huawei.com> From: John Garry Message-ID: Date: Thu, 22 Jul 2021 12:12:05 +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-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.26.161] 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/07/2021 11:19, Ming Lei wrote: >> If you check below, you can see that cpu4 services an NVMe irq. From >> checking htop, during the test that cpu is at 100% load, which I put the >> performance drop (vs cpu0) down to. > nvme.poll_queues is 2 in my test, and no irq is involved. But the irq mode > fio test is still as bad as io_uring. > I tried that: dmesg | grep -i nvme [ 0.000000] Kernel command line: BOOT_IMAGE=/john/Image rdinit=/init crashkernel=256M@32M console=ttyAMA0,115200 earlycon acpi=force pcie_aspm=off noinitrd root=/dev/sda1 rw log_buf_len=16M user_debug=1 iommu.strict=1 nvme.use_threaded_interrupts=0 irqchip.gicv3_pseudo_nmi=1 nvme.poll_queues=2 [ 30.531989] megaraid_sas 0000:08:00.0: NVMe passthru support : Yes [ 30.615336] megaraid_sas 0000:08:00.0: NVME page size : (4096) [ 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. >> Here's some system info: >> >> HW queue irq affinities: >> PCI name is 81:00.0: nvme0n1 >> -eirq 298, cpu list 67, effective list 67 >> -eirq 299, cpu list 32-38, effective list 35 >> -eirq 300, cpu list 39-45, effective list 39 >> -eirq 301, cpu list 46-51, effective list 46 >> -eirq 302, cpu list 52-57, effective list 52 >> -eirq 303, cpu list 58-63, effective list 60 >> -eirq 304, cpu list 64-69, effective list 68 >> -eirq 305, cpu list 70-75, effective list 70 >> -eirq 306, cpu list 76-80, effective list 76 >> -eirq 307, cpu list 81-85, effective list 84 >> -eirq 308, cpu list 86-90, effective list 86 >> -eirq 309, cpu list 91-95, effective list 92 >> -eirq 310, cpu list 96-101, effective list 100 >> -eirq 311, cpu list 102-107, effective list 102 >> -eirq 312, cpu list 108-112, effective list 108 >> -eirq 313, cpu list 113-117, effective list 116 >> -eirq 314, cpu list 118-122, effective list 118 >> -eirq 315, cpu list 123-127, effective list 124 >> -eirq 316, cpu list 0-5, effective list 4 >> -eirq 317, cpu list 6-11, effective list 6 >> -eirq 318, cpu list 12-16, effective list 12 >> -eirq 319, cpu list 17-21, effective list 20 >> -eirq 320, cpu list 22-26, effective list 22 >> -eirq 321, cpu list 27-31, effective list 28 >> >> >> john@ubuntu:~$ lscpu | grep NUMA >> NUMA node(s): 4 >> NUMA node0 CPU(s): 0-31 >> NUMA node1 CPU(s): 32-63 >> NUMA node2 CPU(s): 64-95 >> NUMA node3 CPU(s): 96-127 >> >> john@ubuntu:~$ lspci | grep -i non >> 81:00.0 Non-Volatile memory controller: Huawei Technologies Co., Ltd. Device >> 0123 (rev 45) >> >> cat /sys/block/nvme0n1/device/device/numa_node >> 2 > BTW, nvme driver doesn't apply the pci numa node, and I guess the > following patch is needed: > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c > index 11779be42186..3c5e10e8b0c2 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -4366,7 +4366,11 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, > ctrl->dev = dev; > ctrl->ops = ops; > ctrl->quirks = quirks; > +#ifdef CONFIG_NUMA > + ctrl->numa_node = dev->numa_node; > +#else > ctrl->numa_node = NUMA_NO_NODE; > +#endif From a quick look at the code, is this then later set for the PCI device in nvme_pci_configure_admin_queue()? > INIT_WORK(&ctrl->scan_work, nvme_scan_work); > INIT_WORK(&ctrl->async_event_work, nvme_async_event_work); > INIT_WORK(&ctrl->fw_act_work, nvme_fw_act_work); > >> [ 52.968495] nvme 0000:81:00.0: Adding to iommu group 5 >> [ 52.980484] nvme nvme0: pci function 0000:81:00.0 >> [ 52.999881] nvme nvme0: 23/0/0 default/read/poll queues > Looks you didn't enabling polling. In irq mode, it isn't strange > to observe IOPS difference when running fio on different CPUs. If you are still keen to investigate more, then can try either of these: - add iommu.strict=0 to the cmdline - use perf record+annotate to find the hotspot - For this you need to enable psuedo-NMI with 2x steps: CONFIG_ARM64_PSEUDO_NMI=y in defconfig Add irqchip.gicv3_pseudo_nmi=1 See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/Kconfig#n1745 Your kernel log should show: [ 0.000000] GICv3: Pseudo-NMIs enabled using forced ICC_PMR_EL1 synchronisation But my impression is that this may be a HW implementation issue, considering we don't see such a huge drop off on our HW. Thanks, John