From 5a25bfd28c321e522dbe8083ad6219fa2a820610 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 28 Aug 2017 15:06:06 -0400 Subject: svcrdma: Limit RQ depth Ensure that the chosen Receive Queue depth for a newly created transport does not overrun the QP WR limit of the underlying device. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields --- net/sunrpc/xprtrdma/svc_rdma_transport.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 2aa8473dcc97..cdb04f8a0c25 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -167,8 +167,8 @@ static bool svc_rdma_prealloc_ctxts(struct svcxprt_rdma *xprt) { unsigned int i; - /* Each RPC/RDMA credit can consume a number of send - * and receive WQEs. One ctxt is allocated for each. + /* Each RPC/RDMA credit can consume one Receive and + * one Send WQE at the same time. */ i = xprt->sc_sq_depth + xprt->sc_rq_depth; @@ -742,13 +742,18 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) newxprt->sc_max_sge = min((size_t)dev->attrs.max_sge, (size_t)RPCSVC_MAXPAGES); newxprt->sc_max_req_size = svcrdma_max_req_size; - newxprt->sc_max_requests = min_t(u32, dev->attrs.max_qp_wr, - svcrdma_max_requests); - newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests); - newxprt->sc_max_bc_requests = min_t(u32, dev->attrs.max_qp_wr, - svcrdma_max_bc_requests); + newxprt->sc_max_requests = svcrdma_max_requests; + newxprt->sc_max_bc_requests = svcrdma_max_bc_requests; newxprt->sc_rq_depth = newxprt->sc_max_requests + newxprt->sc_max_bc_requests; + if (newxprt->sc_rq_depth > dev->attrs.max_qp_wr) { + pr_warn("svcrdma: reducing receive depth to %d\n", + dev->attrs.max_qp_wr); + newxprt->sc_rq_depth = dev->attrs.max_qp_wr; + newxprt->sc_max_requests = newxprt->sc_rq_depth - 2; + newxprt->sc_max_bc_requests = 2; + } + newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests); newxprt->sc_sq_depth = newxprt->sc_rq_depth; atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth); -- cgit v1.2.3