performanceTimers.c File Reference

Performance timer functions. More...

#include "performanceTimers.h"
#include <stdio.h>
#include <sys/time.h>
#include <string.h>
#include <stdint.h>
#include <inttypes.h>
#include <math.h>
#include "mytype.h"
#include "parallel.h"
#include "yamlOutput.h"

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Data Structures
struct	TimersSt
	Timer data collected. More...

Typedefs
typedef struct TimersSt	Timers
	Timer data collected. More...

Functions
static uint64_t	getTime (void)
	Returns current time as a 64-bit integer. More...
static double	getTick (void)
	Returns the factor for converting the integer time reported by getTime into seconds. More...
static void	timerStats (void)
	Collect timer statistics across ranks. More...
void	profileStart (const enum TimerHandle handle)
	Use profileStart and profileStop only for timers that should never be turned off. More...
void	profileStop (const enum TimerHandle handle)
double	getElapsedTime (const enum TimerHandle handle)
	Use to get elapsed time (lap timer). More...
void	printPerformanceResults (int nGlobalAtoms)
	Print timing results. More...
void	printPerformanceResultsYaml (FILE *file)
	Print timing results to Yaml file. More...

Variables
char *	timerName [numberOfTimers]
	You must add timer name in same order as enum in .h file. More...
static Timers	perfTimer [numberOfTimers]

Detailed Description

Performance timer functions.

Use the timer functionality to collect timing and number of calls information for chosen computations (such as force calls) and communication (such as sends, receives, reductions). Timing results are reported at the end of the run showing overall timings and statistics of timings across ranks.

A new timer can be added as follows:

1. add new handle to the TimerHandle in performanceTimers.h
2. provide a corresponding name in timerName

Note that the order of the handles and names must be the same. This order also determines the order in which the timers are printed. Names can contain leading spaces to show a hierarchical ordering. Timers with zero calls are omitted from the report.

Raw timer data is obtained from the getTime() and getTick() functions. The supplied portable versions of these functions can be replaced with platform specific versions for improved accuracy or lower latency.

See Also

TimerHandle

getTime

getTick

Definition in file performanceTimers.c.

Typedef Documentation

typedef struct TimersSt Timers

Timer data collected.

Also facilitates computing averages and statistics.

Function Documentation

double getElapsedTime

(

const enum TimerHandle

handle

)

Use to get elapsed time (lap timer).

Return elapsed time (in seconds) since last call with this handle and clear for next lap.

Definition at line 99 of file performanceTimers.c.

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static double getTick ( void  )

static

Returns the factor for converting the integer time reported by getTime into seconds.

The portable getTime returns values in units of microseconds so the conversion is simply 1e-6.

See Also

getTime

Definition at line 225 of file performanceTimers.c.

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static uint64_t getTime ( void  )

static

Returns current time as a 64-bit integer.

This portable version returns the number of microseconds since mindight, Jamuary 1, 1970. Hence, timing data will have a resolution of 1 microsecond. Platforms with access to calls with lower latency or higher resolution (such as a cycle counter) may wish to replace this implementation and change the conversion factor in getTick as appropriate.

See Also

getTick for the conversion factor between the integer time units of this function and seconds.

Definition at line 211 of file performanceTimers.c.

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void printPerformanceResults

(

int

nGlobalAtoms

)

Print timing results.

The report contains two blocks. The upper block is performance information for the printRank. The lower block is statistical information over all ranks.

Definition at line 111 of file performanceTimers.c.

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void printPerformanceResultsYaml

(

FILE *

file

)

Print timing results to Yaml file.

Definition at line 159 of file performanceTimers.c.

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void profileStart

(

const enum TimerHandle

handle

)

Use profileStart and profileStop only for timers that should never be turned off.

Typically this means they are outside the main simulation loop. If the timer is inside the main loop use startTimer and stopTimer instead.

Definition at line 83 of file performanceTimers.c.

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void profileStop

(

const enum TimerHandle

handle

)

Definition at line 88 of file performanceTimers.c.

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void timerStats ( void  )

static

Collect timer statistics across ranks.

Definition at line 232 of file performanceTimers.c.

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Variable Documentation

Timers perfTimer[numberOfTimers]

static

Definition at line 81 of file performanceTimers.c.

char* timerName[numberOfTimers]

Initial value:

= {
   "total",
   "loop",
   "timestep",
   "  position",
   "  velocity",
   "  redistribute",
   "    atomHalo",
   "  force",
   "    eamHalo",
   "commHalo",
   "commReduce"
}

You must add timer name in same order as enum in .h file.

Leading spaces can be specified to show a hierarchy of timers.

Definition at line 49 of file performanceTimers.c.