From 9ba6d5529dd919b442eedf5bef1dd28aca2ee9fe Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 12 Apr 2007 18:10:25 +0300 Subject: [PATCH] IB/mthca: Work around kernel QP starvation With mthca, RC QPs can starve each other and even UD QPs on the same hardware schedule queue. As a result, userspace MPI can starve e.g. IPoIB traffic, with netdev watchdog warnings getting printed out, and TCP connections getting stuck or failing. Reduce the chance of this happening by using three separate hardware schedule queues: one for userspace RC QPs, one for kernel RC QPs, and one for all other QPs. Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mthca/mthca_qp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c index 8fe6fee7a97a..fee60c852d14 100644 --- a/drivers/infiniband/hw/mthca/mthca_qp.c +++ b/drivers/infiniband/hw/mthca/mthca_qp.c @@ -701,6 +701,19 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask, qp_param->opt_param_mask |= cpu_to_be32(MTHCA_QP_OPTPAR_PRIMARY_ADDR_PATH); } + if (ibqp->qp_type == IB_QPT_RC && + cur_state == IB_QPS_INIT && new_state == IB_QPS_RTR) { + u8 sched_queue = ibqp->uobject ? 0x2 : 0x1; + + if (mthca_is_memfree(dev)) + qp_context->rlkey_arbel_sched_queue |= sched_queue; + else + qp_context->tavor_sched_queue |= cpu_to_be32(sched_queue); + + qp_param->opt_param_mask |= + cpu_to_be32(MTHCA_QP_OPTPAR_SCHED_QUEUE); + } + if (attr_mask & IB_QP_TIMEOUT) { qp_context->pri_path.ackto = attr->timeout << 3; qp_param->opt_param_mask |= cpu_to_be32(MTHCA_QP_OPTPAR_ACK_TIMEOUT); -- GitLab