fabtests: Support TX first pingpong test

The new pingpong test allows for TX operations to be posted and
processed, if necessary, before post the RX buffer. This better aligns
to how OSU latency works. By doing this, fi_rdm_tagged_latency is now
lower than OSU latency which makes sense since less SW is involved.

The TX first pingpong can be enabled by used the -T option.

Signed-off-by: Ian Ziemba <ian.ziemba@hpe.com>

fabtests/benchmarks/benchmark_shared.c

@@ -70,6 +70,12 @@ void ft_parse_benchmark_opts(int op, char *optarg)
 	case 'W':
 		opts.window_size = atoi(optarg);
 		break;
+	case 'T':
+		/* Reuse FT_OPT_SKIP_MSG_ALLOC as a flag to post transmits
+		 * before receives.
+		 */
+		opts.options |= FT_OPT_SKIP_MSG_ALLOC;
+		break;
 	default:
 		break;
 	}
@@ -84,6 +90,11 @@ void ft_benchmark_usage(void)
 			"* The following condition is required to have at least "
 			"one window\nsize # of messsages to be sent: "
 			"# of iterations > window size");
+	FT_PRINT_OPTS_USAGE("-T", "Post transmit operations (e.g. fi_send, fi_tsend) before receives");
+	FT_PRINT_OPTS_USAGE("", "Using this option requires out-of-band address exchange and synchronization (i.e. -b must be used)");
+	FT_PRINT_OPTS_USAGE("", "Only the following tests support this option for now:");
+	FT_PRINT_OPTS_USAGE("", "\tfi_rdm_tagged_pingpong");
+	FT_PRINT_OPTS_USAGE("", "\tfi_rdm_pingpong");
 }
 
 /* Pingpong latency test with pre-posted receive buffers. */
@@ -134,6 +145,72 @@ static int pingpong_pre_posted_rx(size_t inject_size)
 	return FI_SUCCESS;
 }
 
+/* Pingpong latency test with transmit operations emitted before posting recv
+ * buffer. For inject transfers, this allows HW backed providers to generate
+ * packets while processing the posted RX command.
+ */
+static int pingpong_tx_first(size_t inject_size)
+{
+	int ret;
+	int i;
+
+	if (opts.dst_addr) {
+		for (i = 0; i < opts.iterations + opts.warmup_iterations; i++) {
+			if (i == opts.warmup_iterations)
+				ft_start();
+
+			if (opts.transfer_size <= inject_size)
+				ret = ft_inject(ep, remote_fi_addr,
+						opts.transfer_size);
+			else
+				ret = ft_tx(ep, remote_fi_addr,
+					    opts.transfer_size, &tx_ctx);
+			if (ret)
+				return ret;
+
+			ret = ft_post_rx(ep, opts.transfer_size, &rx_ctx);
+			if (ret)
+				return ret;
+
+			ret = ft_get_rx_comp(rx_seq);
+			if (ret)
+				return ret;
+		}
+	} else {
+		for (i = 0; i < opts.iterations + opts.warmup_iterations; i++) {
+			if (i == opts.warmup_iterations)
+				ft_start();
+
+			ret = ft_post_rx(ep, opts.transfer_size, &rx_ctx);
+			if (ret)
+				return ret;
+
+			ret = ft_get_rx_comp(rx_seq);
+			if (ret)
+				return ret;
+
+			if (ft_check_opts(FT_OPT_VERIFY_DATA | FT_OPT_ACTIVE)) {
+				ret = ft_check_buf((char *) rx_buf + ft_rx_prefix_size(),
+						   opts.transfer_size);
+				if (ret)
+					return ret;
+			}
+
+			if (opts.transfer_size <= inject_size)
+				ret = ft_inject(ep, remote_fi_addr,
+						opts.transfer_size);
+			else
+				ret = ft_tx(ep, remote_fi_addr,
+					    opts.transfer_size, &tx_ctx);
+			if (ret)
+				return ret;
+		}
+	}
+	ft_stop();
+
+	return FI_SUCCESS;
+}
+
 int pingpong(void)
 {
 	int ret;
@@ -156,7 +233,11 @@ int pingpong(void)
 	if (ret)
 		return ret;
 
-	ret = pingpong_pre_posted_rx(inject_size);
+	if (ft_check_opts(FT_OPT_SKIP_MSG_ALLOC))
+		ret = pingpong_tx_first(inject_size);
+	else
+		ret = pingpong_pre_posted_rx(inject_size);
+
 	if (ret)
 		return ret;
 
@@ -173,10 +254,22 @@ int run_pingpong(void)
 {
 	int i, ret = 0;
 
+	if (ft_check_opts(FT_OPT_SKIP_MSG_ALLOC) &&
+	    !ft_check_opts(FT_OPT_OOB_SYNC)) {
+		FT_ERR("out-of-band address exchange and synchronization required");
+		return EXIT_FAILURE;
+	}
+
 	ret = ft_init_fabric();
 	if (ret)
 		return ret;
 
+	if (ft_check_opts(FT_OPT_SKIP_MSG_ALLOC)) {
+		ret = ft_alloc_msgs();
+		if (ret)
+			return ret;
+	}
+
 	if (!(opts.options & FT_OPT_SIZE)) {
 		for (i = 0; i < TEST_CNT; i++) {
 			if (!ft_use_size(i, opts.sizes_enabled))

fabtests/benchmarks/benchmark_shared.h

@@ -40,7 +40,7 @@ extern "C" {
 
 #include <rdma/fi_rma.h>
 
-#define BENCHMARK_OPTS "vkj:W:"
+#define BENCHMARK_OPTS "Tvkj:W:"
 #define FT_BENCHMARK_MAX_MSG_SIZE (test_size[TEST_CNT - 1].size)
 
 void ft_parse_benchmark_opts(int op, char *optarg);