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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B092C433EF for ; Fri, 5 Nov 2021 12:04:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC8B96124F for ; Fri, 5 Nov 2021 12:04:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232852AbhKEMHD (ORCPT ); Fri, 5 Nov 2021 08:07:03 -0400 Received: from mx3.molgen.mpg.de ([141.14.17.11]:50819 "EHLO mx1.molgen.mpg.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S232693AbhKEMHD (ORCPT ); Fri, 5 Nov 2021 08:07:03 -0400 Received: from [192.168.0.2] (ip5f5ae8e7.dynamic.kabel-deutschland.de [95.90.232.231]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 7AEEE61EA191E; Fri, 5 Nov 2021 13:04:22 +0100 (CET) Message-ID: <0f86c80b-aa6b-e1fd-5fda-0a4e4093250d@molgen.mpg.de> Date: Fri, 5 Nov 2021 13:04:22 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: How to reduce PCI initialization from 5 s (1.5 s adding them to IOMMU groups)s Content-Language: en-US From: Paul Menzel To: =?UTF-8?B?SsO2cmcgUsO2ZGVs?= , Suravee Suthikulpanit , Bjorn Helgaas Cc: iommu@lists.linux-foundation.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, LKML , linux-pci@vger.kernel.org References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Dear Linux folks, Am 05.11.21 um 12:56 schrieb Paul Menzel: > On a PowerEdge T440/021KCD, BIOS 2.11.2 04/22/2021, Linux 5.10.70 takes > almost five seconds to initialize PCI. According to the timestamps, 1.5 > s are from assigning the PCI devices to the 142 IOMMU groups. > > ``` > $ lspci | wc -l > 281 > $ dmesg > […] > [    2.918411] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug > [    2.933841] ACPI: Enabled 5 GPEs in block 00 to 7F > [    2.973739] ACPI: PCI Root Bridge [PC00] (domain 0000 [bus 00-16]) > [    2.980398] acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI HPX-Type3] > [    2.989457] acpi PNP0A08:00: _OSC: platform does not support [LTR] > [    2.995451] acpi PNP0A08:00: _OSC: OS now controls [PME PCIeCapability] > [    3.001394] acpi PNP0A08:00: FADT indicates ASPM is unsupported, > using BIOS configuration > [    3.010511] PCI host bridge to bus 0000:00 > […] > [    6.233508] system 00:05: [io  0x1000-0x10fe] has been reserved > [    6.239420] system 00:05: Plug and Play ACPI device, IDs PNP0c02 (active) > [    6.239906] pnp: PnP ACPI: found 6 devices > […] > [    6.989016] pci 0000:d7:05.0: disabled boot interrupts on device [8086:2034] > [    6.996063] PCI: CLS 0 bytes, default 64 > [    7.000008] Trying to unpack rootfs image as initramfs... > [    7.065281] Freeing initrd memory: 5136K > […] > [    7.079098] DMAR: dmar7: Using Queued invalidation > [    7.083983] pci 0000:00:00.0: Adding to iommu group 0 > […] > [    8.537808] pci 0000:d7:17.1: Adding to iommu group 141 > [    8.571191] DMAR: Intel(R) Virtualization Technology for Directed I/O > [    8.577618] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) > […] > ``` > > Is there anything that could be done to reduce the time? I created an issue at the Kernel.org Bugzilla, and attached the output of `dmesg` there [1]. Kind regards, Paul [1]: https://bugzilla.kernel.org/show_bug.cgi?id=214953