DosPerfSysCall

Purpose

DosPerfSysCall retrieves system performance information and performs software tracing.

Syntax

#define INCL_BASE
#include  os2.h>

APIRET DosPerfSysCall

(ULONG ulCommand, ULONG ulParm1, ULONG ulParm1,ULONG ulParm2, ULONG ulParm3)

Parameters

ulCommand (ULONG) input

CMD_KI_RDCNT 0x63

Reads CPU utilization information in both uniprocessor and symmetric multi-processor (SMP) environments by taking a snapshot of the time stamp counters. To determine CPU utilization, the application must compute the difference between two time stamp snapshots using 64 bit aritimetic. See the example code for details.

Records software trace information.

CMD_KI_RDCNT

ulParm1 would be set to the address of the CPUUTIL structure.

ulParm2and ulParm3are not used and should be set to zero.

Major code for the trace entry in the range of 0 to 255. Major codes 184 (0x00b8) and 185 (0x00b9) have been reserved for customer use. Major code 1 is reserved for exclusive use by IBM(R).

CMD_KI_RDCNT

0 (reserved)

Minor code for the trace entry in the range of 0 to 255.

CMD_KI_RDCNT

0 (reserved)

Pointer to a HOOKDATA data structure.

Returns

ulrc (APIRET) returns

DosPerfSysCall returns one of the following values

NO_ERROR
ERROR_INVALID_FUNCTION

Remarks

DosPerfSysCall is a general purpose performance function. This function accepts four parameters. The first parameter is the command requested. The other three parameters are command specific.

Some functions of DosPerfSysCall may have a dependency on Intel Pentium or Pentium-Pro support. If a function cannot be provided because OS/2 is not running on a processor with the required features, a return code will indicate an attempt to use an unsupported function.

Example Code

This example uses DosPerfSysCall to obtain CPU utilization information.

#define INCL_BASE#include  os2.h>
#include  stdio.h>
#include  stdlib.h>
#include  string.h>
#include  perfutil.h>

#define LL2F (high, low) (4294967296.0* (high) + (low)

void main (int argc, char *argv[])
{

   APIRET   rc;
   int      i, iter, sleep_sec;
   double   ts_val, idle_val_prev;
   double   idle_val, busy_val_prev;
   double   busy_val, busy_val_prev;
   dobule   intr_val intr_val_prev;
   CPUUTIL  CPUUtil;

   if ((argc   2) || (*aargv[1]   '1') || (*aargv[1] > '9')) {
     fprintf(stderr, "usage  %s [1-9]\n", argv[0]);
     exit(0);
   }
   sleep_sec = *argv[1] - '0';

   iter = 0;
   do {
     rec = DosPerfSysCall (CMD_KI_RDCNT, (ULONG)  CPUUtil,0,0);
     if (rc) {
        fprintf (stderr, "CMD_KI_RDCNT failed rc = %d\n", rc);
        exit(1);
     }
     ts_val = LL2F (CPUUtil.ulTimeHigh, CPUUtil.ulTimeLow);
     idle_val = LL2f (CPUUtil.ulIdleHigh, CPUUtil.ulIdleLow);
     busy_val = LL2F (CPUUtil.ulBusyHigh, CPUUtil.ulBusyLow);
     intr_val = LL2F (CPUUtil.ulIntrHigh, CPUUtil.ulIntrLow);

     if (iter > 0) {
        double ts_delta = ts_val - ts_val_prev;
        printf ("idle  %4.2%% busy  %4.2f%% intr  %4.2f%%\n";
           (idle_val - idle_val_prev/ts_delta*100.0,
           (busy_val - busy_val_prev/ts_delta*100.0,
           (intr_val - intr_val_prev/ts_delta*100.0);
     }
     ts_val_prev = ts_val;
     idle_val_prev = idle_val;
     busy_val_prev = busy_val;
     intr_val_prev = intr_val;

     iter++;
     DosSleep(1000*sleep_sec);

   } while (1);
}

This example performs software tracing from a program in ring 3.

#define INCL_BASE
#include  os2.h>
#include  stdio.h>
#include  stdlib.h>
#include  string.h>
#include  perfutil.h>

int main (int argc, char *argv[])
{
   APIRET     rc;
   BYTE       HookBuffer [256];
   HOOKDATA   Hookdata = {0,HookBuffer};
   ULONG      ulMajor, ulMinor;
   *((PULONG)  HookBuffer[0]) = 1;
   *((PULONG)  HookBuffer[4]) = 2;
   *((PULONG)  HookBuffer[8]) = 3;
   strcpy((PSZ  HookBuffer[12], "Test of 3 ULONG values and a string.")
   HookData.ulLength = 12 + strlen((PSZ HookBuffer[12]) + 1;

   ulMajor = 0x00b8 
   ulMinor = 0x0001

   rc = DosPerfSystCall(CMD_SOFTTRACE_LOG, ulMajor, ulMinor, (ULONG)  HookData);
   if (rc != NO_ERROR) {
     fprintf (stderr, "CMD_SOFTTRACE_LOG failed   rc = %u\n", rc);
     return 1;
     }

   return NO_ERROR;
}

[Back: DosOpenL]

[Next: DosProtectOpenL]