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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E52CCC04EB8 for ; Wed, 12 Dec 2018 07:11:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B1A6C20851 for ; Wed, 12 Dec 2018 07:11:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1A6C20851 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726239AbeLLHLm (ORCPT ); Wed, 12 Dec 2018 02:11:42 -0500 Received: from verein.lst.de ([213.95.11.211]:60258 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726242AbeLLHLm (ORCPT ); Wed, 12 Dec 2018 02:11:42 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id 3401768D8D; Wed, 12 Dec 2018 08:11:40 +0100 (CET) Date: Wed, 12 Dec 2018 08:11:40 +0100 From: Christoph Hellwig To: Sagi Grimberg , Jens Axboe Cc: linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, Christoph Hellwig , Keith Busch Subject: Re: [PATCH RFC 4/4] nvme-multipath: disable polling for underlying namespace request queue Message-ID: <20181212071140.GD28461@lst.de> References: <20181211233652.9705-1-sagi@grimberg.me> <20181211233652.9705-5-sagi@grimberg.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181211233652.9705-5-sagi@grimberg.me> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org [adding Jens] > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -1547,6 +1547,8 @@ static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id) > if (ns->head->disk) { > nvme_update_disk_info(ns->head->disk, ns, id); > blk_queue_stack_limits(ns->head->disk->queue, ns->queue); > + /* XXX: multipath device does not support polling for now... */ > + blk_queue_flag_clear(QUEUE_FLAG_POLL, ns->queue); I'd drop the XXX. But I think we actually have a block layer problem here. Currently stacking devices will just pass through REQ_HIPRI, despite none of them supporting any polling for it. So we need to make sure in the block layer or I/O submitter that REQ_HIPRI is only set if QUEUE_FLAG_POLL is supported. I think it would also help if we rename it to REQ_POLL to make this more obvious.