Return-Path: Received: from mail-ig0-f182.google.com ([209.85.213.182]:34528 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754486AbbKWWUb (ORCPT ); Mon, 23 Nov 2015 17:20:31 -0500 Subject: [PATCH v1 2/8] svcrdma: Define maximum number of backchannel requests From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Mon, 23 Nov 2015 17:20:30 -0500 Message-ID: <20151123222030.13040.19373.stgit@klimt.1015granger.net> In-Reply-To: <20151123221738.13040.26277.stgit@klimt.1015granger.net> References: <20151123221738.13040.26277.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: Extra resources for handling backchannel requests have to be pre-allocated when a transport instance is created. Set a limit. Signed-off-by: Chuck Lever --- include/linux/sunrpc/svc_rdma.h | 5 +++++ net/sunrpc/xprtrdma/svc_rdma_transport.c | 6 +++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index f869807..478aa30 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -178,6 +178,11 @@ struct svcxprt_rdma { #define RPCRDMA_SQ_DEPTH_MULT 8 #define RPCRDMA_MAX_REQUESTS 32 #define RPCRDMA_MAX_REQ_SIZE 4096 +#if defined(CONFIG_SUNRPC_BACKCHANNEL) +#define RPCRDMA_MAX_BC_REQUESTS 8 +#else +#define RPCRDMA_MAX_BC_REQUESTS 0 +#endif #define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index b348b4a..01c7b36 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -923,8 +923,10 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) (size_t)RPCSVC_MAXPAGES); newxprt->sc_max_sge_rd = min_t(size_t, devattr.max_sge_rd, RPCSVC_MAXPAGES); + /* XXX: what if HCA can't support enough WRs for bc operation? */ newxprt->sc_max_requests = min((size_t)devattr.max_qp_wr, - (size_t)svcrdma_max_requests); + (size_t)(svcrdma_max_requests + + RPCRDMA_MAX_BC_REQUESTS)); newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_max_requests; /* @@ -964,7 +966,9 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) qp_attr.event_handler = qp_event_handler; qp_attr.qp_context = &newxprt->sc_xprt; qp_attr.cap.max_send_wr = newxprt->sc_sq_depth; + qp_attr.cap.max_send_wr += RPCRDMA_MAX_BC_REQUESTS; qp_attr.cap.max_recv_wr = newxprt->sc_max_requests; + qp_attr.cap.max_recv_wr += RPCRDMA_MAX_BC_REQUESTS; qp_attr.cap.max_send_sge = newxprt->sc_max_sge; qp_attr.cap.max_recv_sge = newxprt->sc_max_sge; qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;