Using the tool collectl it is possible to measure a number of performance indicators under Linux. Particularly interesting are the methods to measure properties like CPU and memory consumption per taks / thread.

Example Code

// Filename: example.c #include #include #include #include void *f1(void *arg) { while (1) { usleep(1); printf("f1\n"); } return NULL; } void *f2(void *arg) { while (1) { usleep(1); float j = sqrt(cos(sin(1.2))); printf("stuff: %f\n",j); } return NULL; }

int main(void) { pthread_t p1,p2; pthread_create(&p1,NULL,f1,”f1…”); pthread_create(&p2,NULL,f2,”f2…”);

while (1) { float i = sqrt(1.2); printf(“main stuff: %f\n”,i); } pthread_join(p1, NULL); pthread_join(p2, NULL); return 0; }

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Compile the code

gcc -lm -lpthreads example.c

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Running Collectl

sh-4.1$ collectl -sZ -i5:10 –procopts t

waiting for 10 second sample…

RECORD 1 »> machine «< (1355908840.001) (Wed Dec 19 10:20:40 2012)

PROCESS SUMMARY (counters are /sec)

PID User PR PPID THRD S VSZ RSS CP SysT UsrT Pct AccuTime RKB WKB MajF MinF Command

……. 25989 5053 20 17675 2 S 28M 636K 3 1.20 0.41 16 0:02.14 0 0 0 0 ./a.out 25990+ 5053 20 25989 2 S 28M 636K 3 0.43 0.05 4 0:00.63 0 0 0 0 a.out 25991+ 5053 20 25989 2 S 28M 636K 3 0.33 0.13 4 0:00.60 0 0 0 0 a.out …….