perfstat_cpu_util interface
The perfstat_cpu_util interface returns
a set of structures of type perfstat_cpu_util_t,
which is defined in the libperfstat.h file
The
perfstat_cpu_util interface includes
the following fields:
| Item | Descriptor |
|---|---|
| cpu_id | Holds CPU ID |
| entitlement | Partition's entitlement |
| user_pct | Percentage of utilization in user mode |
| kern_pct | Percentage of utilization in kernel mode |
| idle_pct | Percentage of utilization in idle mode |
| wait_pct | Percentage of utilization in wait mode |
| physical_busy | Physical CPU is busy |
| physical_consumed | Total CPUs consumed by the partition |
| freq_pct | Average frequency over the last interval in percentage |
| entitlement_pct | Percentage of entitlement used |
| busy_pct | Percentage of entitlement busy |
| idle_donated_pct | Percentage of idle cycles donated |
| busy_donated_pct | Percentage of busy cycles donated |
| idle_stolen_pct | Percentage of idle cycles stolen |
| busy_stolen_pct | Percentage of busy cycles stolen |
| float l_user_pct | Percentage of utilization in user mode in terms of the logical processor ticks |
| float l_kern_pct | Percentage of utilization in kernel mode in terms of the logical processor ticks |
| float l_idle_pct | Percentage of utilization in idle mode in terms of the logical processor ticks |
| float l_wait_pct | Percentage of utilization in wait mode in terms of the logical processor ticks |
| u_longlong_t delta_time | Percentage of the delta time in milliseconds for which the utilization is evaluated |
Both system utilization and per CPU utilization can
be obtained by using theperfstat_cpu_util by mentioning
the type field of the perfstat_rawdata_t data structure
as UTIL_CPU_TOTAL or UTIL_CPU respectively. UTIL_CPU_TOTAL and UTIL_CPU are
the macros, which can be referred in the definition of the perfstat_rawdata_t data
structure.
The use of the
perrfstat_cpu_util API
for system-level utilization follows: #include <libperfstat.h>
#define PERIOD 5
void main()
{
perfstat_cpu_total_t *newt, *oldt;
perfstat_cpu_util_t *util;
perfstat_rawdata_t data;
int rc;
oldt = (perfstat_cpu_total_t*)malloc(sizeof(perfstat_cpu_total_t)*1);
if(oldt==NULL){
perror ("malloc");
exit(-1);
}
newt = (perfstat_cpu_total_t*)malloc(sizeof(perfstat_cpu_total_t)*1);
if(newt==NULL){
perror ("malloc");
exit(-1);
}
util = (perfstat_cpu_util_t*)malloc(sizeof(perfstat_cpu_util_t)*1);
if(util==NULL){
perror ("malloc");
exit(-1);
}
rc = perfstat_cpu_total(NULL, oldt, sizeof(perfstat_cpu_total_t), 1);
if(rc <= 0)
{
perror("Error in perfstat_cpu_total");
exit(-1);
}
sleep(PERIOD);
rc = perfstat_cpu_total(NULL, newt, sizeof(perfstat_cpu_total_t), 1);
if(rc <= 0)
{
perror("Error in perfstat_cpu_total");
exit(-1);
}
data.type = UTIL_CPU_TOTAL;
data.curstat = newt; data.prevstat= oldt;
data.sizeof_data = sizeof(perfstat_cpu_total_t);
data.cur_elems = 1;
data.prev_elems = 1;
rc = perfstat_cpu_util(&data, util,sizeof(perfstat_cpu_util_t), 1);
if(rc <= 0)
{
perror("Error in perfstat_cpu_util");
exit(-1);
}
printf("=======Overall CPU Utilization Metrics=======\n");
printf("Utilization Metrics for a period of %d seconds\n",PERIOD);
printf("User Percentage = %f\n",util->user_pct);
printf("System Percentage = %f\n",util->kern_pct);
printf("Idle Percentage = %f\n",util->idle_pct);
printf("Wait Percentage = %f\n",util->wait_pct);
printf("Physical Busy = %f\n",util->physical_busy);
printf("Physical Consumed = %f\n",util->physical_consumed);
printf("Freq Percentage = %f\n",util->freq_pct);
printf("Entitlement Used Percentage = %f\n",util->entitlement_pct);
printf("Entitlement Busy Percentage = %f\n",util->busy_pct);
printf("Idle Cycles Donated Percentage = %f\n",util->idle_donated_pct);
printf("Busy Cycles Donated Percentage = %f\n",util->busy_donated_pct);
printf("Idle Cycles Stolen Percentage = %f\n",util->idle_stolen_pct);
printf("Busy Cycles Stolen Percentage = %f\n",util->busy_stolen_pct);
printf("User percentage for logical cpu in ticks = %f\n",util->l_user_pct);
printf("Sytem percentage for logical cpu in ticks= %f\n",util->l_kern_pct);
printf("Idle percentage for logical cpu in ticks= %f\n",util->l_idle_pct);
printf("Wait percentage for logical cpu in ticks= %f\n",util->l_wait_pct);
printf("delta time in milliseconds = %llu \n",util->delta_time);
printf("=============================================\n");
}=======Overall CPU Utilization Metrics=======
Utilization Metrics for a period of 5 seconds
User Percentage = 0.050689
System Percentage = 0.262137
Idle Percentage = 99.687172
Wait Percentage = 0.000000
Physical Busy = 0.003128
Physical Consumed = 0.008690
Freq Percentage = 99.935417
Entitlement Used Percentage = 0.869017
Entitlement Busy Percentage = 0.312826
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
User percentage for logical cpu in ticks = 0.000000
Sytem percentage for logical cpu in ticks= 0.082034
Idle percentage for logical cpu in ticks= 99.917969
Wait percentage for logical cpu in ticks= 0.000000
delta time in milliseconds = 4980The
example code to calculate system utilization per CPU, and CPU utilization,
by using the
perfstat_cpu_util interface follows:#include <libperfstat.h>
#define PERIOD 5
void main()
{
perfstat_rawdata_t data;
perfstat_cpu_util_t *util;
perfstat_cpu_t *newt,*oldt;
perfstat_id_t id;
int i,cpu_count,rc;
/* Check how many perfstat_cpu_t structures are available */
cpu_count = perfstat_cpu(NULL, NULL,sizeof(perfstat_cpu_t),0);
/* check for error */
if(cpu_count <= 0)
{
perror("Error in perfstat_cpu");
exit(-1);
}
/* allocate enough memory */
oldt = (perfstat_cpu_t *)calloc(cpu_count,sizeof(perfstat_cpu_t));
if(oldt == NULL)
{
perror("Memory Allocation Error");
exit(-1);
}
/* set name to first cpu */
strcpy(id.name,FIRST_CPU);
/* ask to get all the structures available in one call */
rc = perfstat_cpu(&id, oldt, sizeof(perfstat_cpu_t), cpu_count);
/* check for error */
if(rc <=0)
{
perror("Error in perfstat_cpu");
exit(-1);
}
data.type = UTIL_CPU;
data.prevstat= oldt;
data.sizeof_data = sizeof(perfstat_cpu_t);
data.prev_elems = cpu_count;
sleep(PERIOD);
/* Check how many perfstat_cpu_t structures are available after a defined period */
cpu_count = perfstat_cpu(NULL, NULL,sizeof(perfstat_cpu_t),0);
/* Check for error */
if(cpu_count <= 0)
{
perror("Error in perfstat_cpu");
exit(-1);
}
data.cur_elems = cpu_count;
if(data.prev_elems != data.cur_elems)
{
perror("The number of CPUs has become different for defined period");
exit(-1);
}
/* allocate enough memory */
newt = (perfstat_cpu_t *)calloc(cpu_count,sizeof(perfstat_cpu_t));
util = (perfstat_cpu_util_t *)calloc(cpu_count,sizeof(perfstat_cpu_util_t));
if(newt == NULL || util == NULL)
{
perror("Memory Allocation Error");
exit(-1);
}
data.curstat = newt;
rc = perfstat_cpu(&id, newt, sizeof(perfstat_cpu_t), cpu_count);
if(rc <= 0)
{
perror("Error in perfstat_cpu");
exit(-1);
}
/* Calculate CPU Utilization Metrics*/
rc = perfstat_cpu_util(&data, util, sizeof(perfstat_cpu_util_t), cpu_count);
if(rc <= 0)
{
perror("Error in perfstat_cpu_util");
exit(-1);
}
printf("========= Per CPU Utilization Metrics =========\n");
printf("Utilization Metrics for a period of %d seconds\n",PERIOD);
printf("===============================================\n");
for ( i = 0;i<cpu_count;i++)
{
printf("Utilization metrics for CPU-ID = %s\n",util[i].cpu_id);
printf("User Percentage = %f\n",util[i].user_pct);
printf("System Percentage = %f\n",util[i].kern_pct);
printf("Idle Percentage = %f\n",util[i].idle_pct);
printf("Wait Percentage = %f\n",util[i].wait_pct);
printf("Physical Busy = %f\n",util[i].physical_busy);
printf("Physical Consumed = %f\n",util[i].physical_consumed);
printf("Freq Percentage = %f\n",util[i].freq_pct);
printf("Entitlement Used Percentage = %f\n",util[i].entitlement_pct);
printf("Entitlement Busy Percentage = %f\n",util[i].busy_pct);
printf("Idle Cycles Donated Percentage = %f\n",util[i].idle_donated_pct);
printf("Busy Cycles Donated Percentage = %f\n",util[i].busy_donated_pct);
printf("Idle Cycles Stolen Percentage = %f\n",util[i].idle_stolen_pct);
printf("Busy Cycles Stolen Percentage = %f\n",util[i].busy_stolen_pct);
printf("system percentage for logical cpu in ticks = %f\n",util[i].l_kern_pct);
printf("idle percentage for logical cpu in ticks = %f\n",util[i].l_idle_pct);
printf("wait percentage for logical cpu in ticks = %f\n",util[i].l_wait_pct);
printf("delta time in milliseconds = %llu \n",util[i].delta_time);
printf("\n\n");
}
printf("===========================================\n");
}========= Per CPU Utilization Metrics =========
Utilization Metrics for a period of 5 seconds
===============================================
Utilization metrics for CPU-ID = cpu0
User Percentage = 14.850358
System Percentage = 63.440376
Idle Percentage = 21.709267
Wait Percentage = 0.000000
Physical Busy = 0.003085
Physical Consumed = 0.003941
Freq Percentage = 99.975967
Entitlement Used Percentage = 0.394055
Entitlement Busy Percentage = 0.308508
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.000000
idle percentage for logical cpu in ticks = 100.000000
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 4999
Utilization metrics for CPU-ID = cpu1
User Percentage = 0.000000
System Percentage = 4.720662
Idle Percentage = 95.279335
Wait Percentage = 0.000000
Physical Busy = 0.000065
Physical Consumed = 0.001371
Freq Percentage = 99.938919
Entitlement Used Percentage = 0.137110
Entitlement Busy Percentage = 0.006472
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.000000
idle percentage for logical cpu in ticks = 100.000000
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 5000
Utilization metrics for CPU-ID = cpu2
User Percentage = 0.000000
System Percentage = 5.848962
Idle Percentage = 94.151039
Wait Percentage = 0.000000
Physical Busy = 0.000079
Physical Consumed = 0.001348
Freq Percentage = 99.900566
Entitlement Used Percentage = 0.134820
Entitlement Busy Percentage = 0.007886
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.000000
idle percentage for logical cpu in ticks = 100.000000
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 5000
Utilization metrics for CPU-ID = cpu3
User Percentage = 0.000000
System Percentage = 4.644570
Idle Percentage = 95.355431
Wait Percentage = 0.000000
Physical Busy = 0.000061
Physical Consumed = 0.001312
Freq Percentage = 99.925430
Entitlement Used Percentage = 0.131174
Entitlement Busy Percentage = 0.006092
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.000000
idle percentage for logical cpu in ticks = 100.000000
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 5000
Utilization metrics for CPU-ID = cpu4
User Percentage = 0.000000
System Percentage = 55.325123
Idle Percentage = 44.674877
Wait Percentage = 0.000000
Physical Busy = 0.000153
Physical Consumed = 0.000276
Freq Percentage = 99.927551
Entitlement Used Percentage = 0.027605
Entitlement Busy Percentage = 0.015273
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.000000
idle percentage for logical cpu in ticks = 100.000000
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 4999
Utilization metrics for CPU-ID = cpu5
User Percentage = 0.000000
System Percentage = 1.854463
Idle Percentage = 98.145538
Wait Percentage = 0.000000
Physical Busy = 0.000002
Physical Consumed = 0.000113
Freq Percentage = 99.612183
Entitlement Used Percentage = 0.011326
Entitlement Busy Percentage = 0.000210
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.255102
idle percentage for logical cpu in ticks = 99.744896
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 3913
Utilization metrics for CPU-ID = cpu6
User Percentage = 0.000000
System Percentage = 1.776852
Idle Percentage = 98.223145
Wait Percentage = 0.000000
Physical Busy = 0.000002
Physical Consumed = 0.000115
Freq Percentage = 99.475967
Entitlement Used Percentage = 0.011506
Entitlement Busy Percentage = 0.000204
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.255102
idle percentage for logical cpu in ticks = 99.744896
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 3912
Utilization metrics for CPU-ID = cpu7
User Percentage = 0.000000
System Percentage = 2.138275
Idle Percentage = 97.861725
Wait Percentage = 0.000000
Physical Busy = 0.000002
Physical Consumed = 0.000112
Freq Percentage = 99.593727
Entitlement Used Percentage = 0.011205
Entitlement Busy Percentage = 0.000240
Idle Cycles Donated Percentage = 0.000000
Busy Cycles Donated Percentage = 0.000000
Idle Cycles Stolen Percentage = 0.000000
Busy Cycles Stolen Percentage = 0.000000
system percentage for logical cpu in ticks = 0.255102
idle percentage for logical cpu in ticks = 99.744896
wait percentage for logical cpu in ticks = 0.000000
delta time in milliseconds = 3912