Return-Path: Received: from mail-it0-f66.google.com ([209.85.214.66]:42891 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751098AbeACUmU (ORCPT ); Wed, 3 Jan 2018 15:42:20 -0500 Subject: [PATCH v2 1/3] svcrdma: Post Receives in the Receive completion handler From: Chuck Lever To: bfields@fieldses.org Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 03 Jan 2018 15:42:18 -0500 Message-ID: <20180103204218.7074.75578.stgit@klimt.1015granger.net> In-Reply-To: <20180103203849.7074.9609.stgit@klimt.1015granger.net> References: <20180103203849.7074.9609.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: This change improves Receive efficiency by posting Receives only on the same CPU that handles Receive completion. Improved latency and throughput has been noted with this change. Signed-off-by: Chuck Lever --- include/linux/sunrpc/svc_rdma.h | 2 -- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 5 ----- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 9 +-------- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 6 ------ net/sunrpc/xprtrdma/svc_rdma_transport.c | 25 +++++++------------------ 5 files changed, 8 insertions(+), 39 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 995c6fe..4b731b0 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -185,8 +185,6 @@ extern int svc_rdma_post_send_wr(struct svcxprt_rdma *rdma, extern void svc_rdma_wc_read(struct ib_cq *, struct ib_wc *); extern void svc_rdma_wc_inv(struct ib_cq *, struct ib_wc *); extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *); -extern int svc_rdma_post_recv(struct svcxprt_rdma *, gfp_t); -extern int svc_rdma_repost_recv(struct svcxprt_rdma *, gfp_t); extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *); extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *); extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int); diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index af78935..a73632c 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -95,7 +95,6 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp, out_notfound: dprintk("svcrdma: unrecognized bc reply: xprt=%p, xid=%08x\n", xprt, be32_to_cpu(xid)); - goto out_unlock; } @@ -129,10 +128,6 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, if (ret < 0) goto out_err; - ret = svc_rdma_repost_recv(rdma, GFP_NOIO); - if (ret) - goto out_err; - /* Bump page refcnt so Send completion doesn't release * the rq_buffer before all retransmits are complete. */ diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index ad4bd62..19e9c6b 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -400,10 +400,6 @@ static void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct page *page; int ret; - ret = svc_rdma_repost_recv(xprt, GFP_KERNEL); - if (ret) - return; - page = alloc_page(GFP_KERNEL); if (!page) return; @@ -554,8 +550,6 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) ret = svc_rdma_handle_bc_reply(xprt->xpt_bc_xprt, p, &rqstp->rq_arg); svc_rdma_put_context(ctxt, 0); - if (ret) - goto repost; return ret; } @@ -590,6 +584,5 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) out_drop: svc_rdma_put_context(ctxt, 1); -repost: - return svc_rdma_repost_recv(rdma_xprt, GFP_KERNEL); + return 0; } diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 7c3a211..649441d 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -674,9 +674,6 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) svc_rdma_xdr_encode_reply_chunk(rdma_resp, rp_ch, ret); } - ret = svc_rdma_post_recv(rdma, GFP_KERNEL); - if (ret) - goto err1; ret = svc_rdma_send_reply_msg(rdma, rdma_argp, rdma_resp, rqstp, wr_lst, rp_ch); if (ret < 0) @@ -687,9 +684,6 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (ret != -E2BIG && ret != -EINVAL) goto err1; - ret = svc_rdma_post_recv(rdma, GFP_KERNEL); - if (ret) - goto err1; ret = svc_rdma_send_error_msg(rdma, rdma_resp, rqstp); if (ret < 0) goto err0; diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 46ec069..9ad12a2 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -58,6 +58,7 @@ #define RPCDBG_FACILITY RPCDBG_SVCXPRT +static int svc_rdma_post_recv(struct svcxprt_rdma *xprt); static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *, int); static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, struct net *net, @@ -320,6 +321,8 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) list_add_tail(&ctxt->list, &xprt->sc_rq_dto_q); spin_unlock(&xprt->sc_rq_dto_lock); + svc_rdma_post_recv(xprt); + set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); if (test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags)) goto out; @@ -404,7 +407,8 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, return cma_xprt; } -int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags) +static int +svc_rdma_post_recv(struct svcxprt_rdma *xprt) { struct ib_recv_wr recv_wr, *bad_recv_wr; struct svc_rdma_op_ctxt *ctxt; @@ -423,7 +427,7 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags) pr_err("svcrdma: Too many sges (%d)\n", sge_no); goto err_put_ctxt; } - page = alloc_page(flags); + page = alloc_page(GFP_KERNEL); if (!page) goto err_put_ctxt; ctxt->pages[sge_no] = page; @@ -459,21 +463,6 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags) return -ENOMEM; } -int svc_rdma_repost_recv(struct svcxprt_rdma *xprt, gfp_t flags) -{ - int ret = 0; - - ret = svc_rdma_post_recv(xprt, flags); - if (ret) { - pr_err("svcrdma: could not post a receive buffer, err=%d.\n", - ret); - pr_err("svcrdma: closing transport %p.\n", xprt); - set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); - ret = -ENOTCONN; - } - return ret; -} - static void svc_rdma_parse_connect_private(struct svcxprt_rdma *newxprt, struct rdma_conn_param *param) @@ -833,7 +822,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) /* Post receive buffers */ for (i = 0; i < newxprt->sc_max_requests; i++) { - ret = svc_rdma_post_recv(newxprt, GFP_KERNEL); + ret = svc_rdma_post_recv(newxprt); if (ret) { dprintk("svcrdma: failure posting receive buffers\n"); goto errout;