CPU speed

[Softwaregurl]

I started on this almost a year ago but havn't been able to do anything with it since April and won't be able to do any more anytime soon. It was as much about getting back into programing in C as solving a battery going dead to fast problem. Hope someone else finds it as usefull as I did.

Code: Select all

// Copyright 2011 SoftwareGurl 
// Simple Cpu speed power management that doesn't care about transition latancy 
// A D D   G P L   S T U F F   H E R E 

#include <ctype.h> 
#include <stdio.h> 
#include <string.h> 
#include <stdlib.h> 
#include <unistd.h> 

int vflag = 0,cpuflag = 1,battflag = 0,logflag=0; 
char *battvalue = NULL; 

char version[5]="0.04"; 

float cpu_ulow=550000,cpu_low=825000,cpu_high=2200000,cpu_utrig=20,cpu_ltrig=30,cpu_htrig=50,cpu_hfreq=2200000,cpu_hfold=0; 

float timeout=1,cpu=0,used=0,oldused=0,cputotal=0,oldcputotal=0,cpuold=0; 
char logout[20], logfile[50]="/tmp/mycpuspeed.log"; 
FILE *meminfo,*cpuinfo,*cpuspeed,*cpulog; 

void checkup() { 
  if((cpuinfo=fopen("/proc/stat","r"))==NULL){ 
    fprintf(stderr,"Error opening stat"); 
    exit(1); 
  } 

 unsigned long user,nice,sys,idle,iowait,irq,softirq,virt,virt2; 
 char buf2[190]; 
 char *p; 
 int i; 


 fgets(buf2,190,cpuinfo); strtok(buf2, " "); 
 p=strtok(NULL, " "); user=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); nice=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); sys=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); idle=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); iowait=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); irq=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); softirq=strtol(p, NULL,10); 
 p=strtok(NULL, " "); virt=strtol(p, NULL, 10); 
 p=strtok(NULL, " "); virt2=strtol(p, NULL, 10); 
 fclose(cpuinfo); 

 used=(float)(user+nice+sys+irq+softirq+virt+virt2); 
 cputotal=used+(float)idle+(float)iowait; 

 cpu=((used-oldused)/(cputotal-oldcputotal))*(float)100; 

 oldused=used; 
 oldcputotal=cputotal; 

if(vflag==1) { 
   printf("cpu %.1f total %.1f used %.1f \n",cpu ,cputotal, used); 
} 
 if(cpu<cpu_ltrig){ 
    if(cpu_hfreq>cpu_low) { 
     cpu_hfreq=cpu_low; 
    } 
 } 
 if(cpu>cpu_ltrig) { 
  cpu_hfreq=cpu_low; 
 } 
 if(cpu<cpu_utrig) { 
      cpu_hfreq=cpu_ulow; 
 } 
 if(cpu>cpu_htrig){ 
  cpu_hfreq=cpu_high; 
 } 
   if(cpu!=cpuold) { 
     if((cpuspeed=fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq","w"))==NULL){ 
        fprintf(stderr,"Error opening meminfo"); 
        exit(1); 
      } 
      fprintf(cpuspeed,"%.0f",cpu_hfreq); 
      fclose(cpuspeed); 
      cpuold=cpu; 
   } 
   if(vflag==1) { 
          printf("%.0f %.1f\n", cpu_hfreq, cpu); 
   } 
   if(logflag==1) { 
     if((cpulog=fopen(logfile,"a"))==NULL){ 
    fprintf(stderr,"Error opening meminfo"); 
    exit(1); 
  } 
    fprintf(cpulog, "%.0f %.1f\n", cpu_hfreq, cpu); 
 fclose(cpulog); 
   } 
   return; 
} 

// ################################################################### 
      
int parseopts (int argc, char **argv) { 
       int index; 
       int c; 
      
       opterr = 0; 
      
       while ((c = getopt (argc, argv, "vqlb:c")) != -1) 
         switch (c) 
           { 
           case 'v': 
             vflag = 1; 
             break; 
           case 'q': 
             vflag = 0; 
             break; 
           case 'l': 
             logflag = 1; 
             break; 
           case 'c': 
             cpuflag = 1; 
             break; 
           case 'b': 
             battvalue = optarg; 
             break; 
           case '?': 
             if (optopt == 'c') 
               fprintf (stderr, "Option -%c requires an argument.\n", optopt); 
             else if (isprint (optopt)) 
               fprintf (stderr, "Unknown option `-%c'.\n", optopt); 
             else 
               fprintf (stderr, 
                        "Unknown option character `\\x%x'.\n", 
                        optopt); 
             return 1; 
           default: 
             abort (); 
           } 
     if(vflag==1) { 
       printf ("vflag = %d, cpuflag = %d, battvalue = %s\n", 
               vflag, cpuflag, battvalue); 
      
       for (index = optind; index < argc; index++) 
         printf ("Non-option argument %s\n", argv[index]); 
     } 
       return 0; 
     } 


// ################################################################### 

int main(int argc, char **argv) { 
     fprintf(stdout,"hello world. user space cpu speed version %s\n",version); 
parseopts(argc,argv); 
while(1) 
 { 
//     fprintf(stdout,"hello world. user space cpu speed version %s\n",version); 
 checkup(); 
 sleep(timeout); 
} 
exit(0); 
} 

// BIG REMINDER TO SELF 
// ADD A VERSION LOG HERE 
// O R   E L S E 
// v0.01 first version. Used watcher from Curaga as a start and stripped most away 
//       Thanks Curaga. 
// v0.02 improve efficiency of cpu if-then block 
//       more code stripping and cleanup 
// v0.03 just code cleanup and debugging 
// v0.04 added parseopts subroutine to handle getopt 
//       from an example on gnu.org 
//       added this version log 
//       start doing license stuff 
// v0.05 RESERVED FOR FUTURE USE 
 

this compiles with

Code: Select all

g++ -Os -fno-exceptions -o mycpuspeed mycpuspeed.c  

[/code]

[jamesjeffries2]

Hi Softwaregurl

Great work on this. One quick tip though: g++ is the C++ compiler. It will be easier for the compiler to optimize if you use the C compile - gcc.

Hope this is useful!