[dpdk-dev] [PATCH v9 1/4] lib/librte_power: traffic pattern aware power control

[Liang Ma <liang.j.ma@intel.com>]

1. Abstract

For packet processing workloads such as DPDK polling is continuous.
This means CPU cores always show 100% busy independent of how much work
those cores are doing. It is critical to accurately determine how busy
a core is hugely important for the following reasons:

   * No indication of overload conditions.

   * User does not know how much real load is on a system, resulting
     in wasted energy as no power management is utilized.

Compared to the original l3fwd-power design, instead of going to sleep
after detecting an empty poll, the new mechanism just lowers the core
frequency. As a result, the application does not stop polling the device,
which leads to improved handling of bursts of traffic.

When the system become busy, the empty poll mechanism can also increase the
core frequency (including turbo) to do best effort for intensive traffic.
This gives us more flexible and balanced traffic awareness over the
standard l3fwd-power application.

2. Proposed solution

The proposed solution focuses on how many times empty polls are executed.
The less the number of empty polls, means current core is busy with
processing workload, therefore, the higher frequency is needed. The high
empty poll number indicates the current core not doing any real work
therefore, we can lower the frequency to safe power.

In the current implementation, each core has 1 empty-poll counter which
assume 1 core is dedicated to 1 queue. This will need to be expanded in the
future to support multiple queues per core.

2.1 Power state definition:

	LOW:  Not currently used, reserved for future use.

	MED:  the frequency is used to process modest traffic workload.

	HIGH: the frequency is used to process busy traffic workload.

2.2 There are two phases to establish the power management system:

	a.Initialization/Training phase. The training phase is necessary
	  in order to figure out the system polling baseline numbers from
	  idle to busy. The highest poll count will be during idle, where
	  all polls are empty. These poll counts will be different between
	  systems due to the many possible processor micro-arch, cache
	  and device configurations, hence the training phase.
  	  In the training phase, traffic is blocked so the training
  	  algorithm can average the empty-poll numbers for the LOW, MED and
 	  HIGH  power states in order to create a baseline.
  	  The core's counter are collected every 10ms, and the Training
 	  phase will take 2 seconds.
 	  Training is disabled as default configuration. The default
 	  parameter is applied. Sample App still can trigger training
 	  if that's needed. Once the training phase has been executed once on
 	  a system, the application can then be started with the relevant
 	  thresholds provided on the command line, allowing the application
 	  to start passing start traffic immediately

	b.Normal phase. Traffic starts immediately based on the default
	  thresholds, or based on the user supplied thresholds via the
	  command line parameters. The run-time poll counts are compared with
	  the baseline and the decision will be taken to move to MED power
  	  state or HIGH power state. The counters are calculated every 10ms.

3. Proposed  API

1.  rte_power_empty_poll_stat_init(struct ep_params **eptr,
		uint8_t *freq_tlb, struct ep_policy *policy);
which is used to initialize the power management system.
 
2.  rte_power_empty_poll_stat_free(void);
which is used to free the resource hold by power management system.
 
3.  rte_power_empty_poll_stat_update(unsigned int lcore_id);
which is used to update specific core empty poll counter, not thread safe
 
4.  rte_power_poll_stat_update(unsigned int lcore_id, uint8_t nb_pkt);
which is used to update specific core valid poll counter, not thread safe
 
5.  rte_power_empty_poll_stat_fetch(unsigned int lcore_id);
which is used to get specific core empty poll counter.
 
6.  rte_power_poll_stat_fetch(unsigned int lcore_id);
which is used to get specific core valid poll counter.

7.  rte_empty_poll_detection(struct rte_timer *tim, void *arg);
which is used to detect empty poll state changes then take action.

ChangeLog:
v2: fix some coding style issues.
v3: rename the filename, API name.
v4: no change.
v5: no change.
v6: re-work the code layout, update API.
v7: fix minor typo and lift node num limit.
v8: disable training as default option.
v9: minor git log update.

Signed-off-by: Liang Ma <liang.j.ma@intel.com>

Reviewed-by: Lei Yao <lei.a.yao@intel.com>
---
 lib/librte_power/Makefile               |   6 +-
 lib/librte_power/meson.build            |   5 +-
 lib/librte_power/rte_power_empty_poll.c | 539 ++++++++++++++++++++++++++++++++
 lib/librte_power/rte_power_empty_poll.h | 219 +++++++++++++
 lib/librte_power/rte_power_version.map  |  13 +
 5 files changed, 778 insertions(+), 4 deletions(-)
 create mode 100644 lib/librte_power/rte_power_empty_poll.c
 create mode 100644 lib/librte_power/rte_power_empty_poll.h

diff --git a/lib/librte_power/Makefile b/lib/librte_power/Makefile
index 6f85e88..a8f1301 100644
--- a/lib/librte_power/Makefile
+++ b/lib/librte_power/Makefile
@@ -6,8 +6,9 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_power.a
 
+CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -fno-strict-aliasing
-LDLIBS += -lrte_eal
+LDLIBS += -lrte_eal -lrte_timer
 
 EXPORT_MAP := rte_power_version.map
 
@@ -16,8 +17,9 @@ LIBABIVER := 1
 # all source are stored in SRCS-y
 SRCS-$(CONFIG_RTE_LIBRTE_POWER) := rte_power.c power_acpi_cpufreq.c
 SRCS-$(CONFIG_RTE_LIBRTE_POWER) += power_kvm_vm.c guest_channel.c
+SRCS-$(CONFIG_RTE_LIBRTE_POWER) += rte_power_empty_poll.c
 
 # install this header file
-SYMLINK-$(CONFIG_RTE_LIBRTE_POWER)-include := rte_power.h
+SYMLINK-$(CONFIG_RTE_LIBRTE_POWER)-include := rte_power.h  rte_power_empty_poll.h
 
 include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_power/meson.build b/lib/librte_power/meson.build
index 253173f..63957eb 100644
--- a/lib/librte_power/meson.build
+++ b/lib/librte_power/meson.build
@@ -5,5 +5,6 @@ if host_machine.system() != 'linux'
 	build = false
 endif
 sources = files('rte_power.c', 'power_acpi_cpufreq.c',
-		'power_kvm_vm.c', 'guest_channel.c')
-headers = files('rte_power.h')
+		'power_kvm_vm.c', 'guest_channel.c',
+		'rte_power_empty_poll.c')
+headers = files('rte_power.h','rte_power_empty_poll.h')
diff --git a/lib/librte_power/rte_power_empty_poll.c b/lib/librte_power/rte_power_empty_poll.c
new file mode 100644
index 0000000..587ce78
--- /dev/null
+++ b/lib/librte_power/rte_power_empty_poll.c
@@ -0,0 +1,539 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2018 Intel Corporation
+ */
+
+#include <string.h>
+
+#include <rte_lcore.h>
+#include <rte_cycles.h>
+#include <rte_atomic.h>
+#include <rte_malloc.h>
+
+#include "rte_power.h"
+#include "rte_power_empty_poll.h"
+
+#define INTERVALS_PER_SECOND 100     /* (10ms) */
+#define SECONDS_TO_TRAIN_FOR 2
+#define DEFAULT_MED_TO_HIGH_PERCENT_THRESHOLD 70
+#define DEFAULT_HIGH_TO_MED_PERCENT_THRESHOLD 30
+#define DEFAULT_CYCLES_PER_PACKET 800
+
+static struct ep_params *ep_params;
+static uint32_t med_to_high_threshold = DEFAULT_MED_TO_HIGH_PERCENT_THRESHOLD;
+static uint32_t high_to_med_threshold = DEFAULT_HIGH_TO_MED_PERCENT_THRESHOLD;
+
+static uint32_t avail_freqs[RTE_MAX_LCORE][NUM_FREQS];
+
+static uint32_t total_avail_freqs[RTE_MAX_LCORE];
+
+static uint32_t freq_index[NUM_FREQ];
+
+static uint32_t
+get_freq_index(enum freq_val index)
+{
+	return freq_index[index];
+}
+
+
+static int
+set_power_freq(int lcore_id, enum freq_val freq, bool specific_freq)
+{
+	int err = 0;
+	uint32_t power_freq_index;
+	if (!specific_freq)
+		power_freq_index = get_freq_index(freq);
+	else
+		power_freq_index = freq;
+
+	err = rte_power_set_freq(lcore_id, power_freq_index);
+
+	return err;
+}
+
+
+static inline void __attribute__((always_inline))
+exit_training_state(struct priority_worker *poll_stats)
+{
+	RTE_SET_USED(poll_stats);
+}
+
+static inline void __attribute__((always_inline))
+enter_training_state(struct priority_worker *poll_stats)
+{
+	poll_stats->iter_counter = 0;
+	poll_stats->cur_freq = LOW;
+	poll_stats->queue_state = TRAINING;
+}
+
+static inline void __attribute__((always_inline))
+enter_normal_state(struct priority_worker *poll_stats)
+{
+	/* Clear the averages arrays and strs */
+	memset(poll_stats->edpi_av, 0, sizeof(poll_stats->edpi_av));
+	poll_stats->ec = 0;
+	memset(poll_stats->ppi_av, 0, sizeof(poll_stats->ppi_av));
+	poll_stats->pc = 0;
+
+	poll_stats->cur_freq = MED;
+	poll_stats->iter_counter = 0;
+	poll_stats->threshold_ctr = 0;
+	poll_stats->queue_state = MED_NORMAL;
+	RTE_LOG(INFO, POWER, "set the poewr freq to MED\n");
+	set_power_freq(poll_stats->lcore_id, MED, false);
+
+	/* Try here */
+	poll_stats->thresh[MED].threshold_percent = med_to_high_threshold;
+	poll_stats->thresh[HGH].threshold_percent = high_to_med_threshold;
+}
+
+static inline void __attribute__((always_inline))
+enter_busy_state(struct priority_worker *poll_stats)
+{
+	memset(poll_stats->edpi_av, 0, sizeof(poll_stats->edpi_av));
+	poll_stats->ec = 0;
+	memset(poll_stats->ppi_av, 0, sizeof(poll_stats->ppi_av));
+	poll_stats->pc = 0;
+
+	poll_stats->cur_freq = HGH;
+	poll_stats->iter_counter = 0;
+	poll_stats->threshold_ctr = 0;
+	poll_stats->queue_state = HGH_BUSY;
+	set_power_freq(poll_stats->lcore_id, HGH, false);
+}
+
+static inline void __attribute__((always_inline))
+enter_purge_state(struct priority_worker *poll_stats)
+{
+	poll_stats->iter_counter = 0;
+	poll_stats->queue_state = LOW_PURGE;
+}
+
+static inline void __attribute__((always_inline))
+set_state(struct priority_worker *poll_stats,
+		enum queue_state new_state)
+{
+	enum queue_state old_state = poll_stats->queue_state;
+	if (old_state != new_state) {
+
+		/* Call any old state exit functions */
+		if (old_state == TRAINING)
+			exit_training_state(poll_stats);
+
+		/* Call any new state entry functions */
+		if (new_state == TRAINING)
+			enter_training_state(poll_stats);
+		if (new_state == MED_NORMAL)
+			enter_normal_state(poll_stats);
+		if (new_state == HGH_BUSY)
+			enter_busy_state(poll_stats);
+		if (new_state == LOW_PURGE)
+			enter_purge_state(poll_stats);
+	}
+}
+
+static inline void __attribute__((always_inline))
+set_policy(struct priority_worker *poll_stats,
+		struct ep_policy *policy)
+{
+	set_state(poll_stats, policy->state);
+
+	if (policy->state == TRAINING)
+		return;
+
+	poll_stats->thresh[MED_NORMAL].base_edpi = policy->med_base_edpi;
+	poll_stats->thresh[HGH_BUSY].base_edpi = policy->hgh_base_edpi;
+
+	poll_stats->thresh[MED_NORMAL].trained = true;
+	poll_stats->thresh[HGH_BUSY].trained = true;
+
+}
+
+static void
+update_training_stats(struct priority_worker *poll_stats,
+		uint32_t freq,
+		bool specific_freq,
+		uint32_t max_train_iter)
+{
+	RTE_SET_USED(specific_freq);
+
+	char pfi_str[32];
+	uint64_t p0_empty_deq;
+
+	sprintf(pfi_str, "%02d", freq);
+
+	if (poll_stats->cur_freq == freq &&
+			poll_stats->thresh[freq].trained == false) {
+		if (poll_stats->thresh[freq].cur_train_iter == 0) {
+
+			set_power_freq(poll_stats->lcore_id,
+					freq, specific_freq);
+
+			poll_stats->empty_dequeues_prev =
+				poll_stats->empty_dequeues;
+
+			poll_stats->thresh[freq].cur_train_iter++;
+
+			return;
+		} else if (poll_stats->thresh[freq].cur_train_iter
+				<= max_train_iter) {
+
+			p0_empty_deq = poll_stats->empty_dequeues -
+				poll_stats->empty_dequeues_prev;
+
+			poll_stats->empty_dequeues_prev =
+				poll_stats->empty_dequeues;
+
+			poll_stats->thresh[freq].base_edpi += p0_empty_deq;
+			poll_stats->thresh[freq].cur_train_iter++;
+
+		} else {
+			if (poll_stats->thresh[freq].trained == false) {
+				poll_stats->thresh[freq].base_edpi =
+					poll_stats->thresh[freq].base_edpi /
+					max_train_iter;
+
+				/* Add on a factor of 0.05%*/
+				/* this should remove any */
+				/* false negatives when the system is 0% busy */
+				poll_stats->thresh[freq].base_edpi +=
+					poll_stats->thresh[freq].base_edpi / 2000;
+
+				poll_stats->thresh[freq].trained = true;
+				poll_stats->cur_freq++;
+
+			}
+		}
+	}
+}
+
+static inline uint32_t __attribute__((always_inline))
+update_stats(struct priority_worker *poll_stats)
+{
+	uint64_t tot_edpi = 0, tot_ppi = 0;
+	uint32_t j, percent;
+
+	struct priority_worker *s = poll_stats;
+
+	uint64_t cur_edpi = s->empty_dequeues - s->empty_dequeues_prev;
+
+	s->empty_dequeues_prev = s->empty_dequeues;
+
+	uint64_t ppi = s->num_dequeue_pkts - s->num_dequeue_pkts_prev;
+
+	s->num_dequeue_pkts_prev = s->num_dequeue_pkts;
+
+	if (s->thresh[s->cur_freq].base_edpi < cur_edpi) {
+		RTE_LOG(DEBUG, POWER, "cur_edpi is too large "
+				"cur edpi %ld "
+				"base epdi %ld\n",
+				cur_edpi,
+				s->thresh[s->cur_freq].base_edpi);
+		/* Value to make us fail need debug log*/
+		return 1000UL;
+	}
+
+	s->edpi_av[s->ec++ % BINS_AV] = cur_edpi;
+	s->ppi_av[s->pc++ % BINS_AV] = ppi;
+
+	for (j = 0; j < BINS_AV; j++) {
+		tot_edpi += s->edpi_av[j];
+		tot_ppi += s->ppi_av[j];
+	}
+
+	tot_edpi = tot_edpi / BINS_AV;
+
+	percent = 100 - (uint32_t)(((float)tot_edpi /
+			(float)s->thresh[s->cur_freq].base_edpi) * 100);
+
+	return (uint32_t)percent;
+}
+
+
+static inline void  __attribute__((always_inline))
+update_stats_normal(struct priority_worker *poll_stats)
+{
+	uint32_t percent;
+
+	if (poll_stats->thresh[poll_stats->cur_freq].base_edpi == 0) {
+
+		RTE_LOG(DEBUG, POWER, "cure freq is %d, edpi is %lu\n",
+				poll_stats->cur_freq,
+				poll_stats->thresh[poll_stats->cur_freq].base_edpi);
+		return;
+	}
+
+	percent = update_stats(poll_stats);
+
+	if (percent > 100) {
+		RTE_LOG(DEBUG, POWER, "Big than 100 abnormal\n");
+		return;
+	}
+
+	if (poll_stats->cur_freq == LOW)
+		RTE_LOG(INFO, POWER, "Purge Mode is not supported\n");
+	else if (poll_stats->cur_freq == MED) {
+
+		if (percent >
+			poll_stats->thresh[MED].threshold_percent) {
+
+			if (poll_stats->threshold_ctr < INTERVALS_PER_SECOND)
+				poll_stats->threshold_ctr++;
+			else {
+				set_state(poll_stats, HGH_BUSY);
+				RTE_LOG(INFO, POWER, "MOVE to HGH\n");
+			}
+
+		} else {
+			/* reset */
+			poll_stats->threshold_ctr = 0;
+		}
+
+	} else if (poll_stats->cur_freq == HGH) {
+
+		if (percent <
+				poll_stats->thresh[HGH].threshold_percent) {
+
+			if (poll_stats->threshold_ctr < INTERVALS_PER_SECOND)
+				poll_stats->threshold_ctr++;
+			else {
+				set_state(poll_stats, MED_NORMAL);
+				RTE_LOG(INFO, POWER, "MOVE to MED\n");
+			}
+		} else {
+			/* reset */
+			poll_stats->threshold_ctr = 0;
+		}
+
+	}
+}
+
+static int
+empty_poll_training(struct priority_worker *poll_stats,
+		uint32_t max_train_iter)
+{
+
+	if (poll_stats->iter_counter < INTERVALS_PER_SECOND) {
+		poll_stats->iter_counter++;
+		return 0;
+	}
+
+
+	update_training_stats(poll_stats,
+			LOW,
+			false,
+			max_train_iter);
+
+	update_training_stats(poll_stats,
+			MED,
+			false,
+			max_train_iter);
+
+	update_training_stats(poll_stats,
+			HGH,
+			false,
+			max_train_iter);
+
+
+	if (poll_stats->thresh[LOW].trained == true
+			&& poll_stats->thresh[MED].trained == true
+			&& poll_stats->thresh[HGH].trained == true) {
+
+		set_state(poll_stats, MED_NORMAL);
+
+		RTE_LOG(INFO, POWER, "Low threshold is %lu\n",
+				poll_stats->thresh[LOW].base_edpi);
+
+		RTE_LOG(INFO, POWER, "MED threshold is %lu\n",
+				poll_stats->thresh[MED].base_edpi);
+
+
+		RTE_LOG(INFO, POWER, "HIGH threshold is %lu\n",
+				poll_stats->thresh[HGH].base_edpi);
+
+		RTE_LOG(INFO, POWER, "Training is Complete for %d\n",
+				poll_stats->lcore_id);
+	}
+
+	return 0;
+}
+
+void
+rte_empty_poll_detection(struct rte_timer *tim, void *arg)
+{
+
+	uint32_t i;
+
+	struct priority_worker *poll_stats;
+
+	RTE_SET_USED(tim);
+
+	RTE_SET_USED(arg);
+
+	for (i = 0; i < NUM_NODES; i++) {
+
+		poll_stats = &(ep_params->wrk_data.wrk_stats[i]);
+
+		if (rte_lcore_is_enabled(poll_stats->lcore_id) == 0)
+			continue;
+
+		switch (poll_stats->queue_state) {
+		case(TRAINING):
+			empty_poll_training(poll_stats,
+					ep_params->max_train_iter);
+			break;
+
+		case(HGH_BUSY):
+		case(MED_NORMAL):
+			update_stats_normal(poll_stats);
+			break;
+
+		case(LOW_PURGE):
+			break;
+		default:
+			break;
+
+		}
+
+	}
+
+}
+
+int __rte_experimental
+rte_power_empty_poll_stat_init(struct ep_params **eptr, uint8_t *freq_tlb,
+		struct ep_policy *policy)
+{
+	uint32_t i;
+	/* Allocate the ep_params structure */
+	ep_params = rte_zmalloc_socket(NULL,
+			sizeof(struct ep_params),
+			0,
+			rte_socket_id());
+
+	if (!ep_params)
+		rte_panic("Cannot allocate heap memory for ep_params "
+				"for socket %d\n", rte_socket_id());
+
+	if (freq_tlb == NULL) {
+		freq_index[LOW] = 14;
+		freq_index[MED] = 9;
+		freq_index[HGH] = 1;
+	} else {
+		freq_index[LOW] = freq_tlb[LOW];
+		freq_index[MED] = freq_tlb[MED];
+		freq_index[HGH] = freq_tlb[HGH];
+	}
+
+	RTE_LOG(INFO, POWER, "Initialize the Empty Poll\n");
+
+	/* 5 seconds worth of training */
+	ep_params->max_train_iter = INTERVALS_PER_SECOND * SECONDS_TO_TRAIN_FOR;
+
+	struct stats_data *w = &ep_params->wrk_data;
+
+	*eptr = ep_params;
+
+	/* initialize all wrk_stats state */
+	for (i = 0; i < NUM_NODES; i++) {
+
+		if (rte_lcore_is_enabled(i) == 0)
+			continue;
+		/*init the freqs table */
+		total_avail_freqs[i] = rte_power_freqs(i,
+				avail_freqs[i],
+				NUM_FREQS);
+
+		RTE_LOG(INFO, POWER, "total avail freq is %d , lcoreid %d\n",
+				total_avail_freqs[i],
+				i);
+
+		if (get_freq_index(LOW) > total_avail_freqs[i])
+			return -1;
+
+		if (rte_get_master_lcore() != i) {
+			w->wrk_stats[i].lcore_id = i;
+			set_policy(&w->wrk_stats[i], policy);
+		}
+	}
+
+	return 0;
+}
+
+void __rte_experimental
+rte_power_empty_poll_stat_free(void)
+{
+
+	RTE_LOG(INFO, POWER, "Close the Empty Poll\n");
+
+	if (ep_params != NULL)
+		rte_free(ep_params);
+}
+
+int __rte_experimental
+rte_power_empty_poll_stat_update(unsigned int lcore_id)
+{
+	struct priority_worker *poll_stats;
+
+	if (lcore_id >= NUM_NODES)
+		return -1;
+
+	poll_stats = &(ep_params->wrk_data.wrk_stats[lcore_id]);
+
+	if (poll_stats->lcore_id == 0)
+		poll_stats->lcore_id = lcore_id;
+
+	poll_stats->empty_dequeues++;
+
+	return 0;
+}
+
+int __rte_experimental
+rte_power_poll_stat_update(unsigned int lcore_id, uint8_t nb_pkt)
+{
+
+	struct priority_worker *poll_stats;
+
+	if (lcore_id >= NUM_NODES)
+		return -1;
+
+	poll_stats = &(ep_params->wrk_data.wrk_stats[lcore_id]);
+
+	if (poll_stats->lcore_id == 0)
+		poll_stats->lcore_id = lcore_id;
+
+	poll_stats->num_dequeue_pkts += nb_pkt;
+
+	return 0;
+}
+
+
+uint64_t __rte_experimental
+rte_power_empty_poll_stat_fetch(unsigned int lcore_id)
+{
+	struct priority_worker *poll_stats;
+
+	if (lcore_id >= NUM_NODES)
+		return -1;
+
+	poll_stats = &(ep_params->wrk_data.wrk_stats[lcore_id]);
+
+	if (poll_stats->lcore_id == 0)
+		poll_stats->lcore_id = lcore_id;
+
+	return poll_stats->empty_dequeues;
+}
+
+uint64_t __rte_experimental
+rte_power_poll_stat_fetch(unsigned int lcore_id)
+{
+	struct priority_worker *poll_stats;
+
+	if (lcore_id >= NUM_NODES)
+		return -1;
+
+	poll_stats = &(ep_params->wrk_data.wrk_stats[lcore_id]);
+
+	if (poll_stats->lcore_id == 0)
+		poll_stats->lcore_id = lcore_id;
+
+	return poll_stats->num_dequeue_pkts;
+}
diff --git a/lib/librte_power/rte_power_empty_poll.h b/lib/librte_power/rte_power_empty_poll.h
new file mode 100644
index 0000000..ae27f7d
--- /dev/null
+++ b/lib/librte_power/rte_power_empty_poll.h
@@ -0,0 +1,219 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2018 Intel Corporation
+ */
+
+#ifndef _RTE_EMPTY_POLL_H
+#define _RTE_EMPTY_POLL_H
+
+/**
+ * @file
+ * RTE Power Management
+ */
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <rte_common.h>
+#include <rte_byteorder.h>
+#include <rte_log.h>
+#include <rte_string_fns.h>
+#include <rte_power.h>
+#include <rte_timer.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NUM_FREQS 20
+
+#define BINS_AV 4 /* Has to be ^2 */
+
+#define DROP (NUM_DIRECTIONS * NUM_DEVICES)
+
+#define NUM_PRIORITIES          2
+
+#define NUM_NODES         256  /* Max core number*/
+
+/* Processor Power State */
+enum freq_val {
+	LOW,
+	MED,
+	HGH,
+	NUM_FREQ = NUM_FREQS
+};
+
+
+/* Queue Polling State */
+enum queue_state {
+	TRAINING, /* NO TRAFFIC */
+	MED_NORMAL,   /* MED */
+	HGH_BUSY,     /* HIGH */
+	LOW_PURGE,    /* LOW */
+};
+
+/* Queue Stats */
+struct freq_threshold {
+
+	uint64_t base_edpi;
+	bool trained;
+	uint32_t threshold_percent;
+	uint32_t cur_train_iter;
+};
+
+/* Each Worder Thread Empty Poll Stats */
+struct priority_worker {
+
+	/* Current dequeue and throughput counts */
+	/* These 2 are written to by the worker threads */
+	/* So keep them on their own cache line */
+	uint64_t empty_dequeues;
+	uint64_t num_dequeue_pkts;
+
+	enum queue_state queue_state;
+
+	uint64_t empty_dequeues_prev;
+	uint64_t num_dequeue_pkts_prev;
+
+	/* Used for training only */
+	struct freq_threshold thresh[NUM_FREQ];
+	enum freq_val cur_freq;
+
+	/* bucket arrays to calculate the averages */
+	uint64_t edpi_av[BINS_AV];
+	uint32_t  ec;
+	uint64_t ppi_av[BINS_AV];
+	uint32_t  pc;
+
+	uint32_t lcore_id;
+	uint32_t iter_counter;
+	uint32_t threshold_ctr;
+	uint32_t display_ctr;
+	uint8_t  dev_id;
+
+} __rte_cache_aligned;
+
+
+struct stats_data {
+
+	struct priority_worker wrk_stats[NUM_NODES];
+
+	/* flag to stop rx threads processing packets until training over */
+	bool start_rx;
+
+};
+
+/* Empty Poll Parameters */
+struct ep_params {
+
+	/* Timer related stuff */
+	uint64_t interval_ticks;
+	uint32_t max_train_iter;
+
+	struct rte_timer timer0;
+	struct stats_data wrk_data;
+};
+
+
+/* Sample App Init information */
+struct ep_policy {
+
+	uint64_t med_base_edpi;
+	uint64_t hgh_base_edpi;
+
+	enum queue_state state;
+};
+
+
+
+/**
+ * Initialize the power management system.
+ *
+ * @param eptr
+ *   the structure of empty poll configuration
+ * @freq_tlb
+ *   the power state/frequency  mapping table
+ * @policy
+ *   the initialization policy from sample app
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+int __rte_experimental
+rte_power_empty_poll_stat_init(struct ep_params **eptr, uint8_t *freq_tlb,
+		struct ep_policy *policy);
+
+/**
+ * Free the resource hold by power management system.
+ */
+void __rte_experimental
+rte_power_empty_poll_stat_free(void);
+
+/**
+ * Update specific core empty poll counter
+ * It's not thread safe.
+ *
+ * @param lcore_id
+ *  lcore id
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+int __rte_experimental
+rte_power_empty_poll_stat_update(unsigned int lcore_id);
+
+/**
+ * Update specific core valid poll counter, not thread safe.
+ *
+ * @param lcore_id
+ *  lcore id.
+ * @param nb_pkt
+ *  The packet number of one valid poll.
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+int __rte_experimental
+rte_power_poll_stat_update(unsigned int lcore_id, uint8_t nb_pkt);
+
+/**
+ * Fetch specific core empty poll counter.
+ *
+ * @param lcore_id
+ *  lcore id
+ *
+ * @return
+ *  Current lcore empty poll counter value.
+ */
+uint64_t __rte_experimental
+rte_power_empty_poll_stat_fetch(unsigned int lcore_id);
+
+/**
+ * Fetch specific core valid poll counter.
+ *
+ * @param lcore_id
+ *  lcore id
+ *
+ * @return
+ *  Current lcore valid poll counter value.
+ */
+uint64_t __rte_experimental
+rte_power_poll_stat_fetch(unsigned int lcore_id);
+
+/**
+ * Empty poll  state change detection function
+ *
+ * @param  tim
+ *  The timer structure
+ * @param  arg
+ *  The customized parameter
+ */
+void  __rte_experimental
+rte_empty_poll_detection(struct rte_timer *tim, void *arg);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib/librte_power/rte_power_version.map b/lib/librte_power/rte_power_version.map
index dd587df..11ffdfb 100644
--- a/lib/librte_power/rte_power_version.map
+++ b/lib/librte_power/rte_power_version.map
@@ -33,3 +33,16 @@ DPDK_18.08 {
 	rte_power_get_capabilities;
 
 } DPDK_17.11;
+
+EXPERIMENTAL {
+        global:
+
+        rte_power_empty_poll_stat_init;
+        rte_power_empty_poll_stat_free;
+        rte_power_empty_poll_stat_update;
+        rte_power_empty_poll_stat_fetch;
+        rte_power_poll_stat_fetch;
+        rte_power_poll_stat_update;
+        rte_empty_poll_detection;
+
+};
-- 
2.7.5