From: Christoph Hellwig Subject: Re: [PATCH RFC] scsi: ufs: Disable blk-mq for now Date: Thu, 20 Sep 2018 08:58:04 +0200 Message-ID: <20180920065804.GC13761@lst.de> References: <20180913112848.7807-1-adrian.hunter@intel.com> <20180913120459.GA4965@ming.t460p> <20180914015237.GC11059@ming.t460p> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180914015237.GC11059@ming.t460p> Sender: linux-kernel-owner@vger.kernel.org To: Ming Lei Cc: Adrian Hunter , "Martin K . Petersen" , "James E . J . Bottomley" , Jens Axboe , Christoph Hellwig , Johannes Thumshirn , Bart Van Assche , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Stanislav Nijnikov , Evan Green , Vinayak Holikatti , Janek Kotas , Vivek Gautam , Asutosh Das , Subhash Jadavani , Sayali Lokhande , Li Wei , Bjorn Andersson , Jaegeu List-Id: linux-scsi@vger.kernel.org On Fri, Sep 14, 2018 at 09:52:38AM +0800, Ming Lei wrote: > However, in previous discussion, it is strongly objected to use > per-driver/device .use_blk_mq switch, so not sure if this way can > be accepted. I don't like the per-driver switch as module_parameter at all and we should never do that. We had some exceptions for drivers to force blk_mq (e.g. virtio), and given that I don't think we'll solve the blk-mq runtime-pm issue for 4.19 and also don't want to revert the default I think this patch is the best compromise for 4.19, with a revert in 4.20 once we have runtime-pm for blk-mq. So: Acked-by: Christoph Hellwig