Return-Path: Received: from mail-io0-f195.google.com ([209.85.223.195]:35940 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751334AbeCTVFR (ORCPT ); Tue, 20 Mar 2018 17:05:17 -0400 Subject: [PATCH 2/3] svcrdma: Consult max_qp_init_rd_atom when accepting connections From: Chuck Lever To: bfields@fieldses.org Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Tue, 20 Mar 2018 17:05:15 -0400 Message-ID: <20180320210515.13273.44910.stgit@klimt.1015granger.net> In-Reply-To: <20180320210219.13273.89049.stgit@klimt.1015granger.net> References: <20180320210219.13273.89049.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: The target needs to return the lesser of the client's Inbound RDMA Read Queue Depth (IRD), provided in the connection parameters, and the local device's Outbound RDMA Read Queue Depth (ORD). The latter limit is max_qp_init_rd_atom, not max_qp_rd_atom. The svcrdma_ord value caps the ORD value for iWARP transports, which do not exchange ORD/IRD values at connection time. Since no other Linux kernel RDMA-enabled storage target sees fit to provide this cap, I'm removing it here too. initiator_depth is a u8, so ensure the computed ORD value does not overflow that field. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/svc_rdma.c | 4 ++-- net/sunrpc/xprtrdma/svc_rdma_transport.c | 22 +++++++++------------- 2 files changed, 11 insertions(+), 15 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 8045981..4af0820 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -133,9 +133,6 @@ struct svcxprt_rdma { #define RDMAXPRT_CONN_PENDING 3 #define RPCRDMA_LISTEN_BACKLOG 10 -/* The default ORD value is based on two outstanding full-size writes with a - * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ. */ -#define RPCRDMA_ORD (64/4) #define RPCRDMA_MAX_REQUESTS 32 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c index a4a8f69..dd8a431 100644 --- a/net/sunrpc/xprtrdma/svc_rdma.c +++ b/net/sunrpc/xprtrdma/svc_rdma.c @@ -51,9 +51,9 @@ #define RPCDBG_FACILITY RPCDBG_SVCXPRT /* RPC/RDMA parameters */ -unsigned int svcrdma_ord = RPCRDMA_ORD; +unsigned int svcrdma_ord = 16; /* historical default */ static unsigned int min_ord = 1; -static unsigned int max_ord = 4096; +static unsigned int max_ord = 255; unsigned int svcrdma_max_requests = RPCRDMA_MAX_REQUESTS; unsigned int svcrdma_max_bc_requests = RPCRDMA_MAX_BC_REQUESTS; static unsigned int min_max_requests = 4; diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 8da637a..9c5dadb 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -765,13 +765,6 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) if (!svc_rdma_prealloc_ctxts(newxprt)) goto errout; - /* - * Limit ORD based on client limit, local device limit, and - * configured svcrdma limit. - */ - newxprt->sc_ord = min_t(size_t, dev->attrs.max_qp_rd_atom, newxprt->sc_ord); - newxprt->sc_ord = min_t(size_t, svcrdma_ord, newxprt->sc_ord); - newxprt->sc_pd = ib_alloc_pd(dev, 0); if (IS_ERR(newxprt->sc_pd)) { dprintk("svcrdma: error creating PD for connect request\n"); @@ -846,15 +839,18 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags); memset(&conn_param, 0, sizeof conn_param); conn_param.responder_resources = 0; - conn_param.initiator_depth = newxprt->sc_ord; + conn_param.initiator_depth = min_t(int, newxprt->sc_ord, + dev->attrs.max_qp_init_rd_atom); + if (!conn_param.initiator_depth) { + dprintk("svcrdma: invalid ORD setting\n"); + ret = -EINVAL; + goto errout; + } conn_param.private_data = &pmsg; conn_param.private_data_len = sizeof(pmsg); ret = rdma_accept(newxprt->sc_cm_id, &conn_param); - if (ret) { - dprintk("svcrdma: failed to accept new connection, ret=%d\n", - ret); + if (ret) goto errout; - } dprintk("svcrdma: new connection %p accepted:\n", newxprt); sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr; @@ -865,7 +861,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) dprintk(" sq_depth : %d\n", newxprt->sc_sq_depth); dprintk(" rdma_rw_ctxs : %d\n", ctxts); dprintk(" max_requests : %d\n", newxprt->sc_max_requests); - dprintk(" ord : %d\n", newxprt->sc_ord); + dprintk(" ord : %d\n", conn_param.initiator_depth); return &newxprt->sc_xprt;