From patchwork Tue Aug 8 10:42:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 711857 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 4AC00C001B0 for ; Tue, 8 Aug 2023 16:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232016AbjHHQJz (ORCPT ); Tue, 8 Aug 2023 12:09:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231753AbjHHQIB (ORCPT ); Tue, 8 Aug 2023 12:08:01 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DB7F768C for ; Tue, 8 Aug 2023 08:46:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1691509537; 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=9SdkdgSqxhMyRTJ5vgJIEJL/WyHf61DHGM5o0eLsF7g=; b=YvBnxhU36CDOYSBOQdHgbNyuImwUNI/+w1WgH6QxdoBLgmmamS2iKcVn/YWOkhWckxJ4ow TMBoEEg9Ka2qVqB8sI9avPYEUxfP9v5xsUfdNLyvPZMBz5ExD3YtsNsw0tMJhTc/SNAbD9 ydkT73ihHjhxuDCgn7KNZCreeYbpzjQ= 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-36-HN97ZHsCP7utxVyyzgqj-Q-1; Tue, 08 Aug 2023 06:42:59 -0400 X-MC-Unique: HN97ZHsCP7utxVyyzgqj-Q-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7EAA6185A78B; Tue, 8 Aug 2023 10:42:58 +0000 (UTC) Received: from localhost (unknown [10.72.120.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id A81182166B27; Tue, 8 Aug 2023 10:42:57 +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 V3 03/14] ublk: limit max allowed nr_hw_queues Date: Tue, 8 Aug 2023 18:42:28 +0800 Message-Id: <20230808104239.146085-4-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 10.11.54.6 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. Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 21d2e71c5514..6cf4981951e2 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -2045,7 +2045,7 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; ub->dev_info.nr_hw_queues = min_t(unsigned int, - ub->dev_info.nr_hw_queues, nr_cpu_ids); + ub->dev_info.nr_hw_queues, blk_mq_max_nr_hw_queues()); ublk_align_max_io_size(ub); ret = ublk_init_queues(ub);