From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754504AbbIYLcK (ORCPT ); Fri, 25 Sep 2015 07:32:10 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:60987 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752611AbbIYLcI (ORCPT ); Fri, 25 Sep 2015 07:32:08 -0400 Date: Fri, 25 Sep 2015 04:32:06 -0700 From: Christoph Hellwig To: Dan Williams Cc: Christoph Hellwig , Andrew Morton , Jens Axboe , linux-nvdimm , "linux-kernel@vger.kernel.org" , Linux MM , linux-fsdevel , Ross Zwisler Subject: Re: [PATCH 08/15] block, dax, pmem: reference counting infrastructure Message-ID: <20150925113206.GA22272@infradead.org> References: <20150923043737.36490.70547.stgit@dwillia2-desk3.jf.intel.com> <20150923044155.36490.2017.stgit@dwillia2-desk3.jf.intel.com> <20150924151503.GF24375@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 24, 2015 at 05:03:18PM -0700, Dan Williams wrote: > That makes sense to me, especially because drivers/nvdimm/blk.c is > broken in the same way as drivers/nvdimm/pmem.c and it would be > awkward to have it use blk_dax_get() / blk_dax_put(). The > percpu_refcount should be valid for all queues and it will only ever > be > 1 in the blk_mq and libnvdimm cases (for now). Will fix. Looking at this a bit more it might actually make sense to grab the referene in common code before calling into ->make_request. Jens, any opinion on that?