From patchwork Tue Aug 8 10:42:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 713266 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 025F9C07E8D for ; Tue, 8 Aug 2023 16:25:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232392AbjHHQZQ (ORCPT ); Tue, 8 Aug 2023 12:25:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232461AbjHHQXl (ORCPT ); Tue, 8 Aug 2023 12:23:41 -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 D3100A273 for ; Tue, 8 Aug 2023 08:49:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1691509767; 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=9r/GcSpKKC2dt0ISzH0rvZ1VrInscXGexGqDsV7Zgfk=; b=ZSagAr1lLT3T8NApOJzFqZIX6rZBDJszozcSMmikdXjj2YW198+tICm0fi2fY/ME4Ba8FS uSh1mtdo+bMhJH+nuPcJzCs7UYmVRAwuDjpYZNxx52s/V3JoGP9FTiEojLQSYiXGX3zd09 GwQu9flIj7vI7VUUkt93K05UInkqa5o= 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-610-MBMMJmWsMYifeEoAwq7xkg-1; Tue, 08 Aug 2023 06:48:09 -0400 X-MC-Unique: MBMMJmWsMYifeEoAwq7xkg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 354F4185A7A5; Tue, 8 Aug 2023 10:43:02 +0000 (UTC) Received: from localhost (unknown [10.72.120.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id 62944401061; Tue, 8 Aug 2023 10:43:01 +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 , "Michael S . Tsirkin" , Jason Wang , virtualization@lists.linux-foundation.org Subject: [PATCH V3 04/14] virtio-blk: limit max allowed submit queues Date: Tue, 8 Aug 2023 18:42:29 +0800 Message-Id: <20230808104239.146085-5-ming.lei@redhat.com> In-Reply-To: <20230808104239.146085-1-ming.lei@redhat.com> References: <20230808104239.146085-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Take blk-mq's knowledge into account for calculating io queues. Fix wrong queue mapping in case of kdump kernel. On arm and ppc64, 'maxcpus=1' is passed to kdump command line, see `Documentation/admin-guide/kdump/kdump.rst`, so num_possible_cpus() still returns all CPUs because 'maxcpus=1' just bring up one single cpu core during booting. blk-mq sees single queue in kdump kernel, and in driver's viewpoint there are still multiple queues, this inconsistency causes driver to apply wrong queue mapping for handling IO, and IO timeout is triggered. Meantime, single queue makes much less resource utilization, and reduce risk of kernel failure. Cc: Michael S. Tsirkin Cc: Jason Wang Cc: virtualization@lists.linux-foundation.org Signed-off-by: Ming Lei --- drivers/block/virtio_blk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 1fe011676d07..4ba79fe2a1b4 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1047,7 +1047,8 @@ static int init_vq(struct virtio_blk *vblk) num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); - vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; + vblk->io_queues[HCTX_TYPE_DEFAULT] = min_t(unsigned, + num_vqs - num_poll_vqs, blk_mq_max_nr_hw_queues()); vblk->io_queues[HCTX_TYPE_READ] = 0; vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;