libtrx: fill RDMA Recv queue

libtrx/trx_rdma.c

@@ -13,13 +13,13 @@ void *trx_rdma_recv_thread(void *context) {
 	in_data = (struct SDRMemoryRegion *) sdr_context->in_mr->addr;
 
 	while(1) {
-		// Post a Recv request and poll for completion
-		capulet_rdma_ib_post_recv(&sdr_context->ib_ctx, sdr_context->in_mr, sizeof(struct SDRMemoryRegion));
-
 		do {
 			result = ibv_poll_cq(sdr_context->ib_ctx.recv_cq, 1, &poll_wc);
 		} while(result == 0);
 
+		// Post a Recv request and poll for completion
+		capulet_rdma_ib_post_recv(&sdr_context->ib_ctx, sdr_context->in_mr, sizeof(struct SDRMemoryRegion));
+
 		// Copy data from RDMA buffer to local buffer
 		sample_count = in_data->meta.sample_count;
 		// XXX: should handle multiple channels
@@ -121,6 +121,13 @@ int trx_rdma_start(TRXState *s, const TRXDriverParams2 *p) {
 	result = capulet_rdma_ib_set_peer_from_udp(&sdr_context->ib_ctx, sdr_context->udp_ctx);
 	if(!result) return -1;
 
+	// Fill the Recv queue
+	for(int i = 0; i < 16; i++) {
+		capulet_rdma_ib_post_recv(&sdr_context->ib_ctx, sdr_context->in_mr, sizeof(struct SDRMemoryRegion));
+	}
+
+	usleep(1000);
+
 	// Samples will be received (and sent) using a separate thread which manipulates a finite circular
 	// buffer. The size of the buffer depends on the latency of the network.
 	sdr_context->recv_buffer = common_circular_buffer_create(TRX_RDMA_BUFFER_SAMPLES * sizeof(TRXComplex), false);