From patchwork Wed Jul 12 12:54:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 702650 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83CF6EB64D9 for ; Wed, 12 Jul 2023 12:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232315AbjGLMzz (ORCPT ); Wed, 12 Jul 2023 08:55:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231219AbjGLMzy (ORCPT ); Wed, 12 Jul 2023 08:55:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 781911739 for ; Wed, 12 Jul 2023 05:55:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1689166511; 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=W8fid7Se3iKV/DWozR9uU+XgmFzc7Pg3ogm0vbx3SeA=; b=Ua4VBCnqT68azi8RtJVyx94Artadhw6Bk9HtgFein9L1Fcg7tvLx3h6K04Qu+GIbbIpFry hdJx5Fa4tdjNydDK25ZH3S6BLL53K8prdexKOECvmABF7MepooH892ir5pdqJB3mrbK0CF ZVTZYTwCmXQS3LpxY3IC1fnXuRJVD0c= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-14-xxHbe_10P9uVjg_Q3woLZA-1; Wed, 12 Jul 2023 08:55:07 -0400 X-MC-Unique: xxHbe_10P9uVjg_Q3woLZA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 24A3F8FBA26; Wed, 12 Jul 2023 12:55:07 +0000 (UTC) Received: from localhost (ovpn-8-25.pek2.redhat.com [10.72.8.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id E80FEF66C6; Wed, 12 Jul 2023 12:55:05 +0000 (UTC) From: Ming Lei To: Jens Axboe , Christoph Hellwig , linux-nvme@lists.infradead.org, "Martin K . Petersen" , linux-scsi@vger.kernel.org Cc: linux-block@vger.kernel.org, Wen Xiong , Keith Busch , Ming Lei Subject: [PATCH 1/8] blk-mq: add blk_mq_max_nr_hw_queues() Date: Wed, 12 Jul 2023 20:54:48 +0800 Message-Id: <20230712125455.1986455-2-ming.lei@redhat.com> In-Reply-To: <20230712125455.1986455-1-ming.lei@redhat.com> References: <20230712125455.1986455-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org blk_mq_alloc_tag_set() may override set->nr_hw_queues as 1 in case of kdump kernel. This way causes trouble for driver, because blk-mq and driver see different queue mapping. Especially the only online CPU may not be 1 for kdump kernel, in which 'maxcpus=1' is passed from kernel command line, then driver may map hctx0 into one inactive real hw queue which cpu affinity is 0(offline). The issue exists on all drivers which use managed irq and support multiple hw queue. Prepare for fixing this kind of issue by applying the added helper, so driver can take blk-mq max nr_hw_queues knowledge into account when calculating io queues. Signed-off-by: Ming Lei --- block/blk-mq.c | 9 +++++++++ include/linux/blk-mq.h | 1 + 2 files changed, 10 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 5504719b970d..b764da69a416 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -140,6 +140,15 @@ void blk_mq_freeze_queue_wait(struct request_queue *q) } EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); +/* Max nr_hw_queues for each hw queue type */ +unsigned int blk_mq_max_nr_hw_queues(void) +{ + if (is_kdump_kernel()) + return 1; + return nr_cpu_ids; +} +EXPORT_SYMBOL_GPL(blk_mq_max_nr_hw_queues); + int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, unsigned long timeout) { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 2b7fb8e87793..2407978fbc30 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -713,6 +713,7 @@ int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set, const struct blk_mq_ops *ops, unsigned int queue_depth, unsigned int set_flags); void blk_mq_free_tag_set(struct blk_mq_tag_set *set); +unsigned int blk_mq_max_nr_hw_queues(void); void blk_mq_free_request(struct request *rq); int blk_rq_poll(struct request *rq, struct io_comp_batch *iob,