Merge pull request #1721 from hjelmn/xrc_fix

btl/openib: fix XRC WQE calculation

opal/mca/btl/openib/btl_openib_endpoint.c

@@ -183,12 +183,42 @@ endpoint_init_qp_xrc(mca_btl_base_endpoint_t *ep, const int qp)
         (mca_btl_openib_component.use_eager_rdma ?
          mca_btl_openib_component.max_eager_rdma : 0);
     mca_btl_openib_endpoint_qp_t *ep_qp = &ep->qps[qp];
+    int32_t wqe, incr = mca_btl_openib_component.qp_infos[qp].u.srq_qp.sd_max;
+    int rc;
+
+    opal_mutex_lock (&ep->ib_addr->addr_lock);
+
     ep_qp->qp = ep->ib_addr->qp;
-    ep_qp->qp->sd_wqe += mca_btl_openib_component.qp_infos[qp].u.srq_qp.sd_max;
-    /* make sure that we don't overrun maximum supported by device */
-    if (ep_qp->qp->sd_wqe > max)
-        ep_qp->qp->sd_wqe =  max;
+    if (ep->ib_addr->max_wqe + incr > max) {
+        /* make sure that we don't overrun maximum supported by device */
+        incr = max - ep->ib_addr->max_wqe;
+    }
+
+    wqe = ep->ib_addr->max_wqe + incr +
+        (mca_btl_openib_component.use_eager_rdma ?
+         mca_btl_openib_component.max_eager_rdma : 0);
+
+    ep->ib_addr->max_wqe += incr;
+
+    if (NULL != ep_qp->qp->lcl_qp) {
+        struct ibv_qp_attr qp_attr;
+
+        /* if this is modified the code in udcm_xrc_send_qp_create may
+         * need to be updated as well */
+        qp_attr.cap.max_recv_wr = 0;
+        qp_attr.cap.max_send_wr = wqe;
+        qp_attr.cap.max_inline_data = ep->endpoint_btl->device->max_inline_data;
+        qp_attr.cap.max_send_sge = 1;
+        qp_attr.cap.max_recv_sge = 1; /* we do not use SG list */
+        rc = ibv_modify_qp (ep_qp->qp->lcl_qp, &qp_attr, IBV_QP_CAP);
+        if (0 == rc) {
+            opal_atomic_add_32 (&ep_qp->qp->sd_wqe, incr);
+        }
+    } else {
+        ep_qp->qp->sd_wqe = ep->ib_addr->max_wqe;
+    }
     ep_qp->qp->users++;
+    opal_mutex_unlock (&ep->ib_addr->addr_lock);
 }
 
 static void endpoint_init_qp(mca_btl_base_endpoint_t *ep, const int qp)

opal/mca/btl/openib/btl_openib_endpoint.h

@@ -141,7 +141,7 @@ typedef struct mca_btl_openib_endpoint_srq_qp_t {
 typedef struct mca_btl_openib_qp_t {
     struct ibv_qp *lcl_qp;
     uint32_t lcl_psn;
-    int32_t  sd_wqe;      /**< number of available send wqe entries */
+    volatile int32_t  sd_wqe;      /**< number of available send wqe entries */
     int32_t  sd_wqe_inflight;
     int wqe_count;
     int users;

opal/mca/btl/openib/btl_openib_xrc.c

@@ -125,6 +125,7 @@ static void ib_address_constructor(ib_address_t *ib_addr)
     ib_addr->lid = 0;
     ib_addr->status = MCA_BTL_IB_ADDR_CLOSED;
     ib_addr->qp = NULL;
+    ib_addr->max_wqe = 0;
     /* NTH: make the addr_lock recursive because mca_btl_openib_endpoint_connected can call
      * into the CPC with the lock held. The alternative would be to drop the lock but the
      * lock is never obtained in a critical path. */

opal/mca/btl/openib/btl_openib_xrc.h

@@ -1,3 +1,4 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
 /*
  * Copyright (c) 2007-2008 Mellanox Technologies. All rights reserved.
  * Copyright (c) 2014      Research Organization for Information Science
@@ -5,6 +6,8 @@
  * Copyright (c) 2014      Bull SAS.  All rights reserved.
  * Copyright (c) 2015      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2016      Los Alamos National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -43,6 +46,7 @@ struct ib_address_t {
     uint32_t remote_xrc_rcv_qp_num;        /* remote xrc qp number */
     opal_mutex_t addr_lock;                /* protection */
     mca_btl_openib_ib_addr_state_t status; /* ib port status */
+    int32_t max_wqe;
 };
 typedef struct ib_address_t ib_address_t;
 

opal/mca/btl/openib/connect/btl_openib_connect_udcm.c

@@ -2542,7 +2542,7 @@ static int udcm_xrc_send_qp_create (mca_btl_base_endpoint_t *lcl_ep)
     psn = &lcl_ep->qps[0].qp->lcl_psn;
 
     /* reserve additional wr for eager rdma credit management */
-    send_wr = lcl_ep->ib_addr->qp->sd_wqe +
+    send_wr = lcl_ep->ib_addr->max_wqe +
         (mca_btl_openib_component.use_eager_rdma ?
          mca_btl_openib_component.max_eager_rdma : 0);
 #if OPAL_HAVE_CONNECTX_XRC_DOMAINS
@@ -2554,6 +2554,8 @@ static int udcm_xrc_send_qp_create (mca_btl_base_endpoint_t *lcl_ep)
 
     qp_init_attr.send_cq = qp_init_attr.recv_cq = openib_btl->device->ib_cq[prio];
 
+    /* if this code is update the code in endpoint_init_qp_xrc may need to
+     * be updated as well */
     /* no need recv queue; receives are posted to srq */
     qp_init_attr.cap.max_recv_wr = 0;
     qp_init_attr.cap.max_send_wr = send_wr;