Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:17340 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752647AbbGTWbT convert rfc822-to-8bit (ORCPT ); Mon, 20 Jul 2015 18:31:19 -0400 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: [PATCH v3 05/15] xprtrdma: Remove last ib_reg_phys_mr() call site From: Chuck Lever In-Reply-To: <20150720222608.GA12005@obsidianresearch.com> Date: Mon, 20 Jul 2015 18:31:11 -0400 Cc: linux-rdma , Linux NFS Mailing List Message-Id: <73A27338-7EFC-4F54-A15E-09B9D5145242@oracle.com> References: <20150720185624.10997.51574.stgit@manet.1015granger.net> <20150720190311.10997.12636.stgit@manet.1015granger.net> <20150720222608.GA12005@obsidianresearch.com> To: Jason Gunthorpe Sender: linux-nfs-owner@vger.kernel.org List-ID: On Jul 20, 2015, at 6:26 PM, Jason Gunthorpe wrote: > On Mon, Jul 20, 2015 at 03:03:11PM -0400, Chuck Lever wrote: >> + iov->length = size; >> + iov->lkey = ia->ri_have_dma_lkey ? >> + ia->ri_dma_lkey : ia->ri_bind_mem->lkey; >> + rb->rg_size = size; >> + rb->rg_owner = NULL; >> return rb; > > There is something odd looking about this.. > > ri_bind_mem is only setup in the RPCRDMA_ALLPHYSICAL and > RPCRDMA_MTHCAFMR cases. > > RPCRDMA_FRMR doesn't set it up. > > So this code in rpcrdma_alloc_regbuf is never called for the FRMR > case? > > If yes, then, how is FRMR working? There is absolutely no reason to > use FRMR to register local send buffers, just use the global all > memory lkey... > > If no, then that is an oops? I?ve tested this code, no oops. FRWR always uses the DMA lkey. xprtrdma does not use FRWR if IB_DEVICE_LOCAL_DMA_LKEY is not asserted. FMR and PHYSICAL use the DMA lkey if it exists, otherwise they use an lkey from ib_get_dma_mr. Look in 06/15, this is cleaned up. -- Chuck Lever