I want to calculate Input output performance using /proc/vmstat file?

When I run command cat /proc/vmstat | grep pgpg

The answer is

pgpgin 726854
pgpgout 1010677

I don't want to use command like vmstat or iostat.

By using above values how do I calculate.

  • What I/O performance, disk or network? – pmverma Aug 19 '15 at 8:13
  • I/O performance, like input/output throughput or input/output latency – shas Aug 19 '15 at 9:20
  • pgpgin - Number of kilobytes the system has paged in from disk per second. pgpgout - Number of kilobytes the system has paged out to disk per second. – andr3w Aug 19 '15 at 10:32
  • @andr3w this i know. – shas Aug 19 '15 at 10:34

Got answer for Throughput, from this program I can collect read/write throughput.

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/sysinfo.h>

int main(int argc, char **argv)
    struct sysinfo si;
    sysinfo (&si);
    const double xdt = 1024;
    float  pagein,pageout, oldvalin = 0, oldvalout = 0, res;
    for(;;) {
        FILE *fp=fopen("/proc/vmstat","r");
        char  tmp[256];
        char  subbuff[256];
        while(fp!=NULL && fgets(tmp, sizeof(tmp),fp)!=NULL)
            if (strstr(tmp, "pgpgin")) {
                memcpy( subbuff, &tmp[7], 40);
                subbuff[40] = '\0';
                pagein = atoi(subbuff);
            if (strstr(tmp, "pgpgout")) {
                printf("\n\n%s", tmp);
                memcpy( subbuff, &tmp[7], 40);
                subbuff[40] = '\0';
                pageout = atoi(subbuff);
        printf("Res : %.2f \t %.2f",pagein-oldvalin,pageout-oldvalout);
        oldvalin = pagein;
        oldvalout = pageout;
        if(fp!=NULL) fclose(fp);

Compare with vmstat command. Anything wrong in this code, please comment it. If any one knows about how to calculate latency time, please help me.

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