add VTune support: spin-wait stat

Change-Id: Ie25a87c4b3f781299fa744fdcff6c9a63d473935
Signed-off-by: Roman <roman.sudarikov@intel.com>
Reviewed-on: https://review.gerrithub.io/365723
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>

include/spdk_internal/bdev.h

@@ -151,6 +151,11 @@ struct spdk_bdev_fn_table {
 	 * (most likely another nested object).
 	 */
 	int (*dump_config_json)(void *ctx, struct spdk_json_write_ctx *w);
+
+	/** Get spin-time per I/O channel in microseconds.
+	 *  Optional - may be NULL.
+	 */
+	uint64_t (*get_spin_time)(struct spdk_io_channel *ch);
 };
 
 /** bdev I/O completion status */

lib/bdev/bdev.c

@@ -49,6 +49,8 @@
 
 #ifdef SPDK_CONFIG_VTUNE
 #include "ittnotify.h"
+#include "ittnotify_types.h"
+int __itt_init_ittlib(const char *, __itt_group_id);
 #endif
 
 #define SPDK_BDEV_IO_POOL_SIZE	(64 * 1024)
@@ -646,7 +648,7 @@ spdk_bdev_channel_create(void *io_device, void *ctx_buf)
 #ifdef SPDK_CONFIG_VTUNE
 	{
 		char *name;
-
+		__itt_init_ittlib(NULL, 0);
 		name = spdk_sprintf_alloc("spdk_bdev_%s_%p", ch->bdev->name, ch);
 		if (!name) {
 			return -1;
@@ -1264,15 +1266,17 @@ spdk_bdev_io_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status sta
 #ifdef SPDK_CONFIG_VTUNE
 	uint64_t now_tsc = spdk_get_ticks();
 	if (now_tsc > (bdev_io->ch->start_tsc + bdev_io->ch->interval_tsc)) {
-		uint64_t data[4];
+		uint64_t data[5];
 
 		data[0] = bdev_io->ch->stat.num_read_ops;
 		data[1] = bdev_io->ch->stat.bytes_read;
 		data[2] = bdev_io->ch->stat.num_write_ops;
 		data[3] = bdev_io->ch->stat.bytes_written;
+		data[4] = bdev_io->bdev->fn_table->get_spin_time ?
+			  bdev_io->bdev->fn_table->get_spin_time(bdev_io->ch->channel) : 0;
 
 		__itt_metadata_add(g_bdev_mgr.domain, __itt_null, bdev_io->ch->handle,
-				   __itt_metadata_u64, 4, data);
+				   __itt_metadata_u64, 5, data);
 
 		memset(&bdev_io->ch->stat, 0, sizeof(bdev_io->ch->stat));
 		bdev_io->ch->start_tsc = now_tsc;

lib/bdev/nvme/bdev_nvme.c

@@ -77,6 +77,11 @@ struct nvme_bdev {
 struct nvme_io_channel {
 	struct spdk_nvme_qpair	*qpair;
 	struct spdk_bdev_poller	*poller;
+
+	bool			collect_spin_stat;
+	uint64_t		spin_ticks;
+	uint64_t		start_ticks;
+	uint64_t		end_ticks;
 };
 
 #define NVME_DEFAULT_MAX_UNMAP_BDESC_COUNT	1
@@ -186,9 +191,28 @@ static void
 bdev_nvme_poll(void *arg)
 {
 	struct nvme_io_channel *ch = arg;
+	int32_t num_completions;
 
-	if (ch->qpair != NULL) {
-		spdk_nvme_qpair_process_completions(ch->qpair, 0);
+	if (ch->qpair == NULL) {
+		return;
+	}
+
+	if (ch->collect_spin_stat && ch->start_ticks == 0) {
+		ch->start_ticks = spdk_get_ticks();
+	}
+
+	num_completions = spdk_nvme_qpair_process_completions(ch->qpair, 0);
+
+	if (ch->collect_spin_stat) {
+		if (num_completions > 0) {
+			if (ch->end_ticks != 0) {
+				ch->spin_ticks += (ch->end_ticks - ch->start_ticks);
+				ch->end_ticks = 0;
+			}
+			ch->start_ticks = 0;
+		} else {
+			ch->end_ticks = spdk_get_ticks();
+		}
 	}
 }
 
@@ -423,6 +447,12 @@ bdev_nvme_create_cb(void *io_device, void *ctx_buf)
 	struct spdk_nvme_ctrlr *ctrlr = io_device;
 	struct nvme_io_channel *ch = ctx_buf;
 
+#ifdef SPDK_CONFIG_VTUNE
+	ch->collect_spin_stat = true;
+#else
+	ch->collect_spin_stat = false;
+#endif
+
 	ch->qpair = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, 0);
 
 	if (ch->qpair == NULL) {
@@ -585,12 +615,35 @@ bdev_nvme_dump_config_json(void *ctx, struct spdk_json_write_ctx *w)
 	return 0;
 }
 
+static uint64_t
+bdev_nvme_get_spin_time(struct spdk_io_channel *ch)
+{
+	struct nvme_io_channel *nvme_ch = spdk_io_channel_get_ctx(ch);
+	uint64_t spin_time;
+
+	if (!nvme_ch->collect_spin_stat) {
+		return 0;
+	}
+
+	if (nvme_ch->end_ticks != 0) {
+		nvme_ch->spin_ticks += (nvme_ch->end_ticks - nvme_ch->start_ticks);
+		nvme_ch->end_ticks = 0;
+	}
+
+	spin_time = (nvme_ch->spin_ticks * 1000000ULL) / spdk_get_ticks_hz();
+	nvme_ch->start_ticks = 0;
+	nvme_ch->spin_ticks = 0;
+
+	return spin_time;
+}
+
 static const struct spdk_bdev_fn_table nvmelib_fn_table = {
 	.destruct		= bdev_nvme_destruct,
 	.submit_request		= bdev_nvme_submit_request,
 	.io_type_supported	= bdev_nvme_io_type_supported,
 	.get_io_channel		= bdev_nvme_get_io_channel,
 	.dump_config_json	= bdev_nvme_dump_config_json,
+	.get_spin_time		= bdev_nvme_get_spin_time,
 };
 
 static bool