Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:35725 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132AbbGNTBu convert rfc822-to-8bit (ORCPT ); Tue, 14 Jul 2015 15:01:50 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: [PATCH v2 07/14] xprtrdma: Remove logic that constructs RDMA_MSGP type calls From: Chuck Lever In-Reply-To: <55A55C63.50403@talpey.com> Date: Tue, 14 Jul 2015 15:01:47 -0400 Cc: linux-rdma@vger.kernel.org, Linux NFS Mailing List Message-Id: References: <20150713160617.17630.97475.stgit@manet.1015granger.net> <20150713163048.17630.86326.stgit@manet.1015granger.net> <55A55C63.50403@talpey.com> To: Tom Talpey Sender: linux-nfs-owner@vger.kernel.org List-ID: On Jul 14, 2015, at 3:00 PM, Tom Talpey wrote: > On 7/13/2015 12:30 PM, Chuck Lever wrote: >> RDMA_MSGP type calls insert a zero pad in the middle of the RPC >> message to align the RPC request's data payload to the server's >> alignment preferences. A server can then "page flip" the payload >> into place to avoid a data copy in certain circumstances. However: >> ... >> >> Clean up the marshaling code by removing the logic that constructs >> RDMA_MSGP type calls. This also reduces the maximum send iovec size >> from four to just two elements. >> > >> diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h >> index 8219011..0b50103 100644 >> --- a/net/sunrpc/xprtrdma/xprt_rdma.h >> +++ b/net/sunrpc/xprtrdma/xprt_rdma.h > ...> >> +#define RPCRDMA_MAX_IOVS (4) >> + > > So, shouldn't this constant be "2"? The extra 2 iov's were used > only for constructing the pad. Yes, thanks. I folded a couple of patches together into this one, and forgot to update the constant. -- Chuck Lever