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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 9645CC433ED for ; Wed, 21 Apr 2021 13:32:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56A02611F2 for ; Wed, 21 Apr 2021 13:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242368AbhDUNdI (ORCPT ); Wed, 21 Apr 2021 09:33:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:22692 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240339AbhDUNdH (ORCPT ); Wed, 21 Apr 2021 09:33:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619011953; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eHGylvMWVSknLesn5TIShxESJ3h/B3URDa1h0briNGk=; b=QQhol4s5fvVz5w0CNT8nM+8DvGBfpI2rJ73iNobcXsYgIE33XTieakOHPgvpjJIhIWe2C5 RUDons0QWKpLP16G0U25HeAbQSO8mDhTDL3idhtBT/mcqt+dRXJQ/eI0cQ4mze+5riAA99 FWutE13Q5WNRumiqE+lQM4jw3xz7uq8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-581-97lvuigvP_-ssdBgdw6EGQ-1; Wed, 21 Apr 2021 09:31:45 -0400 X-MC-Unique: 97lvuigvP_-ssdBgdw6EGQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 135081936B6D; Wed, 21 Apr 2021 13:31:44 +0000 (UTC) Received: from [10.10.115.104] (ovpn-115-104.rdu2.redhat.com [10.10.115.104]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4216E10016DB; Wed, 21 Apr 2021 13:31:40 +0000 (UTC) Subject: Re: [IRQ] IRQ affinity not working properly? To: Thomas Gleixner , Chris Friesen , LKML , Jesse Brandeburg References: <87blb3ce29.ffs@nanos.tec.linutronix.de> From: Nitesh Narayan Lal Organization: Red Hat Inc, Message-ID: Date: Wed, 21 Apr 2021 09:31:37 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <87blb3ce29.ffs@nanos.tec.linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/28/21 2:45 PM, Thomas Gleixner wrote: > On Fri, Jan 29 2021 at 13:17, Chris Friesen wrote: >> I have a CentOS 7 linux system with 48 logical CPUs and a number of >> IR-PCI-MSI-edge iavf-net1-TxRx-3 >> 961: 0 0 0 0 28492 0 >> IR-PCI-MSI-edge iavf-0000:b5:02.7:mbx >> 962: 0 0 0 0 435608 0 >> IR-PCI-MSI-edge iavf-net1-TxRx-0 >> 963: 0 0 0 0 394832 0 >> IR-PCI-MSI-edge iavf-net1-TxRx-1 >> 964: 0 0 0 0 398414 0 >> IR-PCI-MSI-edge iavf-net1-TxRx-2 >> 965: 0 0 0 0 192847 0 >> IR-PCI-MSI-edge iavf-net1-TxRx-3 >> >> There were IRQs coming in on the "iavf-0000:b5:02.7:mbx" interrupt at >> roughly 1 per second without any traffic, while the interrupt rate on >> the "iavf-net1-TxRx-" seemed to be related to traffic. >> >> Is this expected? It seems like the IRQ subsystem is not respecting the >> configured SMP affinity for the interrupt in question. I've also seen >> the same behaviour with igb interrupts. > No it's not expected. Do you see the same behaviour with a recent > mainline kernel, i.e. 5.10 or 5.11? > > Jesse pointed me to this thread and apologies that it took a while for me to respond here. I agree it will be interesting to see with which kernel version Chris is reproducing the issue. Initially, I thought that this issue is the same as the one that we have been discussing in another thread [1]. However, in that case, the smp affinity mask itself is incorrect and doesn't follow the default smp affinity mask (with irqbalance disabled). [1] https://lore.kernel.org/lkml/1a044a14-0884-eedb-5d30-28b4bec24b23@redhat.com/ -- Thanks Nitesh