/******************************************************************************
*
* msr_jitter.c
*
* Autor: Wilhelm Hagemeister
*
* (C) Copyright IgH 2002
* Ingenieurgemeinschaft IgH
* Heinz-Bäcker Str. 34
* D-45356 Essen
* Tel.: +49 201/61 99 31
* Fax.: +49 201/61 98 36
* E-mail: hm@igh-essen.com
*
* $Id$
*
*****************************************************************************/
#ifndef __KERNEL__
# define __KERNEL__
#endif
#ifndef MODULE
# define MODULE
#endif
#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <asm/msr.h> /* maschine-specific registers */
#include <linux/param.h> /* fuer HZ */
#include <msr_reg.h>
#include "msr_jitter.h"
/*--includes-----------------------------------------------------------------*/
/*--external functions-------------------------------------------------------*/
/*--external data------------------------------------------------------------*/
/*--public data--------------------------------------------------------------*/
/*--local data---------------------------------------------------------------*/
#define NUMCLASSES 16
static int jittime[NUMCLASSES]={0,1,2,5,10,20,50,100,200,500,
1000,2000,5000,10000,20000,50000}; //in usec
static int jitcount[NUMCLASSES];
static double jitpercent[NUMCLASSES];
static unsigned int tcount = 1;
static void msr_jit_read(void)
{
int i;
for(i=0;i<NUMCLASSES;i++) {
if(tcount >100) {
jitpercent[i] = jitcount[i]*100.0/tcount;
}
}
}
void msr_jitter_init(void)
{
msr_reg_int_list("/Taskinfo/Jitter/Classes","usec",
&jittime[0],MSR_R,NUMCLASSES,NULL,NULL,NULL);
msr_reg_int_list("/Taskinfo/Jitter/Count","",
&jitcount[0],MSR_R,NUMCLASSES,NULL,NULL,NULL);
msr_reg_dbl_list("/Taskinfo/Jitter/percent","%",
&jitpercent[0],MSR_R,NUMCLASSES,NULL,NULL,&msr_jit_read);
}
/******************************************************************************
*
* Function: msr_jitter_run
*
* Beschreibung:
*
*
* Parameter: Zeiger auf msr_data
*
* Rückgabe:
*
* Status: exp
*
*****************************************************************************/
void msr_jitter_run(unsigned int hz) {
int i,hit;
static int firstrun = 1;
static unsigned long k,j = 0;
unsigned int dt,jitter;
rdtscl(k);
tcount++;
//Zeitabstand zwischen zwei Interrupts in usec
dt = ((unsigned long)(100000/HZ)*((unsigned long)(k-j)))
/(current_cpu_data.loops_per_jiffy/10);
jitter = (unsigned int)abs((int)dt-(int)1000000/hz);
//jitter errechnet zum Sollabtastrate
//in die Klassen einsortieren
if(!firstrun) { //das erste mal nicht einsortieren
hit = 0;
for(i=0;i<NUMCLASSES-1;i++) {
if(jitter>=jittime[i] && jitter<jittime[i+1]) {
jitcount[i]++;
hit = 1;
break;
}
}
if(hit == 0) //grŽöŽßer als der letzte
jitcount[NUMCLASSES-1]++;
}
else
firstrun = 0;
j = k;
}