Return-Path: Received: from mail-qg0-f46.google.com ([209.85.192.46]:35012 "EHLO mail-qg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751630AbbGMQaE (ORCPT ); Mon, 13 Jul 2015 12:30:04 -0400 Subject: [PATCH v2 02/14] xprtrdma: Raise maximum payload size to one megabyte From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Mon, 13 Jul 2015 12:30:01 -0400 Message-ID: <20150713163001.17630.43320.stgit@manet.1015granger.net> In-Reply-To: <20150713160617.17630.97475.stgit@manet.1015granger.net> References: <20150713160617.17630.97475.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: The point of larger rsize and wsize is to reduce the per-byte cost of memory registration and deregistration. Modern HCAs can typically handle a megabyte or more with a single registration operation. Signed-off-by: Chuck Lever Reviewed-by: Devesh Sharma Reviewed-By: Sagi Grimberg --- net/sunrpc/xprtrdma/xprt_rdma.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index f49dd8b..abee472 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -165,8 +165,7 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb) * struct rpcrdma_buffer. N is the max number of outstanding requests. */ -/* temporary static scatter/gather max */ -#define RPCRDMA_MAX_DATA_SEGS (64) /* max scatter/gather */ +#define RPCRDMA_MAX_DATA_SEGS ((1 * 1024 * 1024) / PAGE_SIZE) #define RPCRDMA_MAX_SEGS (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */ struct rpcrdma_buffer;