Performance Monitor

The Performance Monitor component provides APIs to use ESP32 internal performance counters to profile functions and applications.

Application Example

An example which combines performance monitor is provided in examples/system/perfmon directory. This example initializes the performance monitor structure and execute them with printing the statistics.

High level API Reference

Header Files

API Reference

Header File

Functions

esp_err_t xtensa_perfmon_init(int id, uint16_t select, uint16_t mask, int kernelcnt, int tracelevel)

Init Performance Monitoor.

Initialize performance monitor register with define values

Parameters

  • id -- [in] performance counter number

  • select -- [in] select value from PMCTRLx register

  • mask -- [in] mask value from PMCTRLx register

  • kernelcnt -- [in] kernelcnt value from PMCTRLx register

  • tracelevel -- [in] tracelevel value from PMCTRLx register

Returns

  • ESP_OK on success

  • ESP_ERR_INVALID_ARG if one of the arguments is not correct

esp_err_t xtensa_perfmon_reset(int id)

Reset PM counter.

Reset PM counter. Writes 0 to the PMx register.

Parameters

id -- [in] performance counter number

Returns

  • ESP_OK on success

  • ESP_ERR_INVALID_ARG if id out of range

void xtensa_perfmon_start(void)

Start PM counters.

Start all PM counters synchronously. Write 1 to the PGM register

void xtensa_perfmon_stop(void)

Stop PM counters.

Stop all PM counters synchronously. Write 0 to the PGM register

uint32_t xtensa_perfmon_value(int id)

Read PM counter.

Read value of defined PM counter.

Parameters

id -- [in] performance counter number

Returns

  • Performance counter value

esp_err_t xtensa_perfmon_overflow(int id)

Read PM overflow state.

Read overflow value of defined PM counter.

Parameters

id -- [in] performance counter number

Returns

  • ESP_OK if there is no overflow (overflow = 0)

  • ESP_FAIL if overflow occure (overflow = 1)

void xtensa_perfmon_dump(void)

Dump PM values.

Dump all PM register to the console.

Header File

Functions

esp_err_t xtensa_perfmon_exec(const xtensa_perfmon_config_t *config)

Execute PM.

Execute performance counter for dedicated function with defined parameters

Parameters

config -- [in] pointer to the configuration structure

Returns

  • ESP_OK if no errors

  • ESP_ERR_INVALID_ARG if one of the required parameters not defined

  • ESP_FAIL - counter overflow

void xtensa_perfmon_view_cb(void *params, uint32_t select, uint32_t mask, uint32_t value)

Dump PM results.

Callback to dump perfmon result to a FILE* stream specified in perfmon_config_t::callback_params. If callback_params is set to NULL, will print to stdout

Parameters

  • params -- [in] used parameters passed from configuration (callback_params). This parameter expected as FILE* hanle, where data will be stored. If this parameter NULL, then data will be stored to the stdout.

  • select -- [in] select value for current counter

  • mask -- [in] mask value for current counter

  • value -- [in] counter value for current counter

Structures

struct xtensa_perfmon_config

Performance monitor configuration structure.

Structure to configure performance counter to measure dedicated function

Public Members

int repeat_count

how much times function will be called before the calback will be repeated

float max_deviation

Difference between min and max counter number 0..1, 0 - no difference, 1 - not used

void *call_params

This pointer will be passed to the call_function as a parameter

void (*call_function)(void *params)

pointer to the function that have to be called

void (*callback)(void *params, uint32_t select, uint32_t mask, uint32_t value)

pointer to the function that will be called with result parameters

void *callback_params

parameter that will be passed to the callback

int tracelevel

trace level for all counters. In case of negative value, the filter will be ignored. If it's >=0, then the perfmon will count only when interrupt level > tracelevel. It's useful to monitor interrupts.

uint32_t counters_size

amount of counter in the list

const uint32_t *select_mask

list of the select/mask parameters

Type Definitions

typedef struct xtensa_perfmon_config xtensa_perfmon_config_t

Performance monitor configuration structure.

Structure to configure performance counter to measure dedicated function

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