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 E55F3C52D70 for ; Tue, 6 Aug 2024 17:15:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5W/f9Go6KqLTcoO7AGO4U5RXIhiU1JoC/JlTAULsf7o=; b=jHCm/TvalbEP+VvmI3Ye3+NK7O RGdfj+9alPCw+xMVfbq12Jz5QorpaShbtkzBUDKke6QMQilpIO709RCV4Shy3rOt/qqygHHed4OnE KV/eA0vbGv4lOXFZ/3xchPRwEgdt+kmIH9OLmtTk4BDE1SN2TuNGjQQS2m2HjHDikZuAxaM1gDLoX B4zUVzwdmMzA/whkuMxQt1txvTOZzwfL5bNPDjHr4P1hNXBtsLinw3kykKlDV+iu9H9GkflDTaPLM AmrKT3Wtr39uYmZJwjfVj8t26PD9U6LGX7R+3lu1IFOWHG4AcAcZFVxLisZAG/2DrZ6DojeSaJjcb +nyC+kpw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sbNme-00000002Sqk-2bAo; Tue, 06 Aug 2024 17:15:40 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sbLbF-000000025Kd-2VTz for linux-nvme@lists.infradead.org; Tue, 06 Aug 2024 14:55:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722956144; 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=5W/f9Go6KqLTcoO7AGO4U5RXIhiU1JoC/JlTAULsf7o=; b=HRFcEpGOP0aGPEm0ud8VgWKaNrZiDwLeOp8H3S+C59v7b1BrNwQUklXanGn573NVTGFsYL lCGCD2mH/fCUPwwXrWUb9UWvJjQP+cK5L0vvL0Jzk5z+7WLcZ0OcPPGFQ8Z0Fdzpy08Lzy RVVUNSxXD7Onq6AVCEJOe/f0gw1mxh4= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-640-HwAq-aLEOvWa8u616gwxEQ-1; Tue, 06 Aug 2024 10:55:39 -0400 X-MC-Unique: HwAq-aLEOvWa8u616gwxEQ-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A54CF1955BEE; Tue, 6 Aug 2024 14:55:33 +0000 (UTC) Received: from fedora (unknown [10.72.116.14]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A49C91956046; Tue, 6 Aug 2024 14:55:15 +0000 (UTC) Date: Tue, 6 Aug 2024 22:55:09 +0800 From: Ming Lei To: Daniel Wagner Cc: Jens Axboe , Keith Busch , Sagi Grimberg , Thomas Gleixner , Christoph Hellwig , "Martin K. Petersen" , John Garry , "Michael S. Tsirkin" , Jason Wang , Kashyap Desai , Sumit Saxena , Shivasharan S , Chandrakanth patil , Sathya Prakash Veerichetty , Suganath Prabu Subramani , Nilesh Javali , GR-QLogic-Storage-Upstream@marvell.com, Jonathan Corbet , Frederic Weisbecker , Mel Gorman , Hannes Reinecke , Sridhar Balaraman , "brookxu.cn" , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, virtualization@lists.linux.dev, megaraidlinux.pdl@broadcom.com, mpi3mr-linuxdrv.pdl@broadcom.com, MPT-FusionLinux.pdl@broadcom.com, storagedev@microchip.com, linux-doc@vger.kernel.org Subject: Re: [PATCH v3 15/15] blk-mq: use hk cpus only when isolcpus=io_queue is enabled Message-ID: References: <20240806-isolcpus-io-queues-v3-0-da0eecfeaf8b@suse.de> <20240806-isolcpus-io-queues-v3-15-da0eecfeaf8b@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240806-isolcpus-io-queues-v3-15-da0eecfeaf8b@suse.de> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240806_075545_733293_E05229CF X-CRM114-Status: GOOD ( 15.32 ) X-Mailman-Approved-At: Tue, 06 Aug 2024 10:15:39 -0700 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Aug 06, 2024 at 02:06:47PM +0200, Daniel Wagner wrote: > When isolcpus=io_queue is enabled all hardware queues should run on the > housekeeping CPUs only. Thus ignore the affinity mask provided by the > driver. Also we can't use blk_mq_map_queues because it will map all CPUs > to first hctx unless, the CPU is the same as the hctx has the affinity > set to, e.g. 8 CPUs with isolcpus=io_queue,2-3,6-7 config What is the expected behavior if someone still tries to submit IO on isolated CPUs? BTW, I don't see any change in blk_mq_get_ctx()/blk_mq_map_queue() in this patchset, that means one random hctx(or even NULL) may be used for submitting IO from isolated CPUs, then there can be io hang risk during cpu hotplug, or kernel panic when submitting bio. Thanks, Ming