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=-16.4 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 B3F8BC07E96 for ; Thu, 15 Jul 2021 12:09:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9DC5361360 for ; Thu, 15 Jul 2021 12:09:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232384AbhGOMMQ (ORCPT ); Thu, 15 Jul 2021 08:12:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38454 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229973AbhGOMMQ (ORCPT ); Thu, 15 Jul 2021 08:12:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626350963; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uEyeHofMx8tj7VEsxrvtta8tXqNSRwnjfqPdjz6a1lM=; b=E48lh5KslV834wfz3cenaJ+gXXtS320nxVeiqUSkSjW+wYN4zuiRjlm3dJcGwptQ4RM50A EbrhflBPbrH8LdM8B7yVlIK1DuuFG2LOAYyPSL8OgiCNgaUwRPHUEy7ak0++gkYdn4oKow +alpI1nvRqwhI8bNU/B28aTXXZkQtiw= 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-297-m9vk4FB5PIWaxLVzrqPSmw-1; Thu, 15 Jul 2021 08:09:19 -0400 X-MC-Unique: m9vk4FB5PIWaxLVzrqPSmw-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 A3CEB800D62; Thu, 15 Jul 2021 12:09:17 +0000 (UTC) Received: from localhost (ovpn-12-61.pek2.redhat.com [10.72.12.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3C2E119C45; Thu, 15 Jul 2021 12:09:12 +0000 (UTC) From: Ming Lei To: Jens Axboe , Christoph Hellwig , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Greg Kroah-Hartman , Bjorn Helgaas , linux-pci@vger.kernel.org Cc: Thomas Gleixner , Sagi Grimberg , Daniel Wagner , Wen Xiong , John Garry , Hannes Reinecke , Keith Busch , Ming Lei Subject: [PATCH V4 3/3] blk-mq: don't deactivate hctx if managed irq isn't used Date: Thu, 15 Jul 2021 20:08:44 +0800 Message-Id: <20210715120844.636968-4-ming.lei@redhat.com> In-Reply-To: <20210715120844.636968-1-ming.lei@redhat.com> References: <20210715120844.636968-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org blk-mq deactivates one hctx when the last CPU in hctx->cpumask become offline by draining all requests originated from this hctx and moving new allocation on other active hctx. This way is for avoiding inflight IO in case of managed irq because managed irq is shutdown when the last CPU in the irq's affinity becomes offline. However, lots of drivers(nvme fc, rdma, tcp, loop, ...) don't use managed irq, so they needn't to deactivate hctx when the last CPU becomes offline. Also, some of them are the only user of blk_mq_alloc_request_hctx() which is used for connecting io queue. And their requirement is that the connect request needs to be submitted successfully via one specified hctx even though all CPUs in this hctx->cpumask have become offline. Addressing the requirement for nvme fc/rdma/loop by allowing to allocate request from one hctx when all CPUs in this hctx are offline, since these drivers don't use managed irq. Finally don't deactivate one hctx when it doesn't use managed irq. Signed-off-by: Ming Lei --- block/blk-mq.c | 27 +++++++++++++++++---------- block/blk-mq.h | 8 ++++++++ 2 files changed, 25 insertions(+), 10 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 2c4ac51e54eb..591ab07c64d8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -427,6 +427,15 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, } EXPORT_SYMBOL(blk_mq_alloc_request); +static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) +{ + int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask); + + if (cpu >= nr_cpu_ids) + cpu = cpumask_first(hctx->cpumask); + return cpu; +} + struct request *blk_mq_alloc_request_hctx(struct request_queue *q, unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx) { @@ -468,7 +477,10 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, data.hctx = q->queue_hw_ctx[hctx_idx]; if (!blk_mq_hw_queue_mapped(data.hctx)) goto out_queue_exit; - cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask); + + WARN_ON_ONCE(blk_mq_hctx_use_managed_irq(data.hctx)); + + cpu = blk_mq_first_mapped_cpu(data.hctx); data.ctx = __blk_mq_get_ctx(q, cpu); if (!q->elevator) @@ -1501,15 +1513,6 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) hctx_unlock(hctx, srcu_idx); } -static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) -{ - int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask); - - if (cpu >= nr_cpu_ids) - cpu = cpumask_first(hctx->cpumask); - return cpu; -} - /* * It'd be great if the workqueue API had a way to pass * in a mask and had some smarts for more clever placement. @@ -2556,6 +2559,10 @@ static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node) struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_online); + /* hctx needn't to be deactivated in case managed irq isn't used */ + if (!blk_mq_hctx_use_managed_irq(hctx)) + return 0; + if (!cpumask_test_cpu(cpu, hctx->cpumask) || !blk_mq_last_cpu_in_hctx(cpu, hctx)) return 0; diff --git a/block/blk-mq.h b/block/blk-mq.h index d08779f77a26..7333b659d8f5 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -119,6 +119,14 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, return ctx->hctxs[type]; } +static inline bool blk_mq_hctx_use_managed_irq(struct blk_mq_hw_ctx *hctx) +{ + if (hctx->type == HCTX_TYPE_POLL) + return false; + + return hctx->queue->tag_set->map[hctx->type].use_managed_irq; +} + /* * sysfs helpers */ -- 2.31.1