Re: [dpdk-dev] [PATCH v7 1/4] lib/librte_power: traffic pattern aware power control

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

Hi Kevin,
   Many thanks for your comments.
   I will send v8 patch soon. 
   Please check comments below. 

On 13 Sep 11:54, Kevin Traynor wrote:
> On 09/04/2018 03:10 PM, Liang Ma wrote:
> > 1. Abstract
> > 
> 
> Hi Liang,
> 
> I didn't review the code, but some comments on API below,
> 
> > 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 do not know how much real load is on a system meaning resulted 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
> 
> When you say 'traffic is blocked' is this something that the application
> can do through DPDK API, or you mean no external packets are sent into
> that port?a
training is disabled as default. if user enable it, that mean no external packet
are sent to the port. 

> 
> >   	  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.
> > 
> > 	b.Normal phase. When the training phase is complete, traffic is
> >   	  started. 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(void);
> > 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
> >  
> 
> is uint8_t enough to cover the max burst size for an rx poll? I didn't checka
most comment max burst size is 32. correct me if I'm wrong. 
> 
> > 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.
> > 
> 
> How about replacing 1-6 with something like below..(not sure what would
> be best prefix)
> 
> rte_power_poll_stat_init(void);
> rte_power_poll_stat_free(void);
> rte_power_poll_stat_update(unsigned int lcore, uint8_t nb_pkts)
> rte_power_poll_stat_fetch(unsigned int lcore, uint8_t stat)
> 
> This would mean combining 3./4. as per previous suggestion so the
> application could just call a single function with nb_pkt (which could
> be 0). It also makes it more extensible if you want to add new stats in
> the future, rather than having to add more functions.
> 
> It doesn't do anything different, so perhaps it's just a matter of
> personal tastes.
we use the empty poll counter which is separate with valid poll counter.
that's the fundamental difference. I prefer leave it this moment. 
> 
> > 7.  rte_empty_poll_detection(void);
> > which is used to detect empty poll state changes.
> > 
> 
> s/rte/rte_power/ ?
> 
> I think this needs some better docs/doxygen and maybe name. It seems to
> not just detect state change but take some actions so that should be
> documented, even in a general way.a
agree, I will update the description. 
> 
> thanks,
> Kevin.
> 
> > 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.
> > 
> > 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 | 500 ++++++++++++++++++++++++++++++++
> >  lib/librte_power/rte_power_empty_poll.h | 205 +++++++++++++
> >  lib/librte_power/rte_power_version.map  |  13 +
> >  5 files changed, 725 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..3dac654
> > --- /dev/null
> > +++ b/lib/librte_power/rte_power_empty_poll.c
> > @@ -0,0 +1,500 @@
> > +/* 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;
> > +	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 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)
> > +		return;
> > +
> > +	percent = update_stats(poll_stats);
> > +
> > +	if (percent > 100)
> > +		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 */
> > +			/* need debug log */
> > +			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);
> > +		} else
> > +			/* reset */
> > +			/* need debug log */
> > +			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, "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)
> > +{
> > +	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;
> > +
> > +		set_state(&w->wrk_stats[i], TRAINING);
> > +		/*init the freqs table */
> > +		total_avail_freqs[i] = rte_power_freqs(i,
> > +				avail_freqs[i],
> > +				NUM_FREQS);
> > +
> > +		if (get_freq_index(LOW) > total_avail_freqs[i])
> > +			return -1;
> > +
> > +	}
> > +
> > +
> > +	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..0aca1f0
> > --- /dev/null
> > +++ b/lib/librte_power/rte_power_empty_poll.h
> > @@ -0,0 +1,205 @@
> > +/* 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;
> > +};
> > +
> > +
> > +/**
> > + * Initialize the power management system.
> > + *
> > + * @param eptr
> > + *   the structure of empty poll configuration
> > + * @freq_tlb
> > + *   the power state/frequency  mapping table
> > + *
> > + * @return
> > + *  - 0 on success.
> > + *  - Negative on error.
> > + */
> > +int __rte_experimental
> > +rte_power_empty_poll_stat_init(struct ep_params **eptr, uint8_t *freq_tlb);
> > +
> > +/**
> > + * 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;
> > +
> > +};
> > 
>