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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1715EB64DC for ; Tue, 11 Jul 2023 03:36:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=O+1RJVrH/MD1FXxj9e4pMp8O4godsfgrHgyMrmJf9BQ=; b=XwRU+ppQmHyZ0r s4v7vp1+maB+762Wr+ucbjFxyewtxdBmvP/S2Fj7e6zRVsdy7b2JKNoX6kP2ec4c4nEy7EP/LIG3F cLhdpkCqZqaAzEnhqP9O7o8EYXsrT/MKJXAgLKfEjDCMc2hDIUHD1RmL46sKpoVspAvSlfaecJNFA oSbn2hNjrEh2JRkp6+8F4LBDpr7W/mrcQnWAA6gGF+l474jrHfcurlMbEolOnWr3Cof4rwn1qN72Y cHbc4lMAmemsGtK19Q5XLpysLeUF3sdvhDUWH/7ofKa7QMqT1CITm00U9eYKfPDBgC+Tp5JPscrUJ xtfgQkG11+3QosB5JK+A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qJ4AY-00DUkl-33; Tue, 11 Jul 2023 03:36:07 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qJ4AV-00DUj4-04 for linux-arm-kernel@lists.infradead.org; Tue, 11 Jul 2023 03:36:05 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1689046561; 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=RAKJNLVa7Dz/gEOC8l+W1ubVM3SUfpJDz/d6N9kvm8w=; b=dtOCQgyeZfew8yc4ck0qqex2UgAsZmgASGXB3bhX84Cd0IIDwm/t5uuOCxbIVShvICpGyZ devCD+AhzwrS/VrQ0+r6sU8mnD55RPcM9WN3J3b+nUn46S0OamygbwrcwrY8NNNtK8XoQu n7ooLAi+3uE+lOKbE3bzJYfjf+liPqk= 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-498-rnGtRtxZNxW8idSVCPY9jA-1; Mon, 10 Jul 2023 23:35:56 -0400 X-MC-Unique: rnGtRtxZNxW8idSVCPY9jA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 765518028B2; Tue, 11 Jul 2023 03:35:55 +0000 (UTC) Received: from localhost (ovpn-12-93.pek2.redhat.com [10.72.12.93]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2547DC52D9C; Tue, 11 Jul 2023 03:35:53 +0000 (UTC) Date: Tue, 11 Jul 2023 11:35:50 +0800 From: Baoquan He To: Ming Lei Cc: Christoph Hellwig , Jens Axboe , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Wen Xiong , Keith Busch , Dave Young , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au, Thomas Gleixner Subject: Re: [PATCH 2/2] nvme-pci: use blk_mq_max_nr_hw_queues() to calculate io queues Message-ID: References: <20230708020259.1343736-1-ming.lei@redhat.com> <20230708020259.1343736-3-ming.lei@redhat.com> <20230710064109.GB24519@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230710_203603_149003_33958B04 X-CRM114-Status: GOOD ( 24.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 07/10/23 at 05:14pm, Ming Lei wrote: > On Mon, Jul 10, 2023 at 08:41:09AM +0200, Christoph Hellwig wrote: > > On Sat, Jul 08, 2023 at 10:02:59AM +0800, Ming Lei wrote: > > > 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. > > > > That's simply broken. Please fix the arch code to make sure > > it does not return a bogus num_possible_cpus value for these > > That is documented in Documentation/admin-guide/kdump/kdump.rst. > > On arm and ppc64, 'maxcpus=1' is passed for kdump kernel, and "maxcpu=1" > simply keep one of CPU cores as online, and others as offline. I don't know maxcpus on arm and ppc64 well. But maxcpus=1 or nr_cpus=1 are suggested parameter. Because usually nr_cpus=1 is enough to make kdump kernel work well to capture vmcore. However, user is allowed to specify nr_cpus=n (n>1) if they think multiple cpus are needed in kdump kernel. Your hard coding of cpu number in kdump kernel may be not so reasonable. Please cc kexec mailing list when posting so that people can view the whole thread of discussion. Thanks Baoquan > > So Cc our arch(arm & ppc64) & kdump guys wrt. passing 'maxcpus=1' for > kdump kernel. > > > setups, otherwise you'll have to paper over it in all kind of > > drivers. > > The issue is only triggered for drivers which use managed irq & > multiple hw queues. > > > Thanks, > Ming > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel