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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2867BC11F65 for ; Wed, 30 Jun 2021 07:38:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2F9661D03 for ; Wed, 30 Jun 2021 07:38:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233051AbhF3Hkw (ORCPT ); Wed, 30 Jun 2021 03:40:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:55898 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233010AbhF3Hkw (ORCPT ); Wed, 30 Jun 2021 03:40:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1625038703; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ygn53gMCPK5uQpNuDNfZ0SnQrRr47gyThM24mtG1Fpk=; b=RR/Er+82pnaVN1OUDR2ViXd8Q/8USn9pXeaEUH87VM6EfMvPdpuNSZXZ26D9HRxYHjOfbQ 2tj5F2ze3oqi3cpQWu5w3MnDKayMjunz1Ztz2RRjrDhk7tcpNsgGru4LNrV29Cn0dlRpNO cAKK5OL0t4Hz7VNmwHLTF/qBLpZzqvs= 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-504-0QjpzeVINYKczPN7d0kQQQ-1; Wed, 30 Jun 2021 03:38:21 -0400 X-MC-Unique: 0QjpzeVINYKczPN7d0kQQQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A338E19200C5; Wed, 30 Jun 2021 07:38:20 +0000 (UTC) Received: from T590 (ovpn-13-153.pek2.redhat.com [10.72.13.153]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8F0F1E715; Wed, 30 Jun 2021 07:38:15 +0000 (UTC) Date: Wed, 30 Jun 2021 15:38:11 +0800 From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org Subject: Re: [PATCH] block: build default queue map via irq_create_affinity_masks Message-ID: References: <20210630035153.2099975-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210630035153.2099975-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Jun 30, 2021 at 11:51:53AM +0800, Ming Lei wrote: > The default queue mapping builder of blk_mq_map_queues doesn't take NUMA > topo into account, so the built mapping is pretty bad, since CPUs > belonging to different NUMA node are assigned to same queue. It is > observed that IOPS drops by ~30% when running two jobs on same hctx > of null_blk from two CPUs belonging to two NUMA nodes compared with > from same NUMA node. > > Address the issue by reusing irq_create_affinity_masks() for building > the default queue mapping, so that we can re-use the mapping created > for managed irq. > > Lots of drivers may benefit from the change, such as nvme pci poll, > nvme tcp, ... > > Signed-off-by: Ming Lei > --- > block/blk-mq-cpumap.c | 60 +++++++++---------------------------------- > 1 file changed, 12 insertions(+), 48 deletions(-) > > diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c > index 3db84d3197f1..946e373296a3 100644 > --- a/block/blk-mq-cpumap.c > +++ b/block/blk-mq-cpumap.c > @@ -10,67 +10,31 @@ > #include > #include > #include > +#include > > #include > #include "blk.h" > #include "blk-mq.h" > > -static int queue_index(struct blk_mq_queue_map *qmap, > - unsigned int nr_queues, const int q) > -{ > - return qmap->queue_offset + (q % nr_queues); > -} > - > -static int get_first_sibling(unsigned int cpu) > -{ > - unsigned int ret; > - > - ret = cpumask_first(topology_sibling_cpumask(cpu)); > - if (ret < nr_cpu_ids) > - return ret; > - > - return cpu; > -} > - > int blk_mq_map_queues(struct blk_mq_queue_map *qmap) > { > + struct irq_affinity_desc *masks = NULL; > + struct irq_affinity affd = {0}; > unsigned int *map = qmap->mq_map; > unsigned int nr_queues = qmap->nr_queues; > - unsigned int cpu, first_sibling, q = 0; > + unsigned int q; > > - for_each_possible_cpu(cpu) > - map[cpu] = -1; > + masks = irq_create_affinity_masks(nr_queues, &affd); > + if (!masks) > + return -ENOMEM; > > - /* > - * Spread queues among present CPUs first for minimizing > - * count of dead queues which are mapped by all un-present CPUs > - */ > - for_each_present_cpu(cpu) { > - if (q >= nr_queues) > - break; > - map[cpu] = queue_index(qmap, nr_queues, q++); > - } > + for (q = 0; q < nr_queues; q++) { > + unsigned int cpu; > > - for_each_possible_cpu(cpu) { > - if (map[cpu] != -1) > - continue; > - /* > - * First do sequential mapping between CPUs and queues. > - * In case we still have CPUs to map, and we have some number of > - * threads per cores then map sibling threads to the same queue > - * for performance optimizations. > - */ > - if (q < nr_queues) { > - map[cpu] = queue_index(qmap, nr_queues, q++); > - } else { > - first_sibling = get_first_sibling(cpu); > - if (first_sibling == cpu) > - map[cpu] = queue_index(qmap, nr_queues, q++); > - else > - map[cpu] = map[first_sibling]; > - } > + for_each_cpu(cpu, &masks[q].mask) > + map[cpu] = q; oops, the above line should have been: map[cpu] = qmap->queue_offset + q; Thanks, Ming