Question

In my application, I want to increase CPU usage of application to desired value of user and make it steady till user intrest.
I am calculating total CPU usage using following method using top command.

sample code :

private long getCpuUsageStatistic() {
           usage =0;
          String tempString = executeTop(); // executeTop is method where I fire top command.


           tempString = tempString.replaceAll(",", "");
           tempString = tempString.replaceAll("User", "");
           tempString = tempString.replaceAll("System", "");
           tempString = tempString.replaceAll("IOW", "");
           tempString = tempString.replaceAll("IRQ", "");
           tempString = tempString.replaceAll("%", "");
           for (int i = 0; i < 10; i++) {
                tempString = tempString.replaceAll("  ", " ");
           }
           tempString  = tempString.replaceAll("  ", " ");
           tempString = tempString.trim();
           String[] myString = tempString.split(" ");
           int[] cpuUsageAsInt = new int[myString.length]; 
           for (int i = 0; i < 2; i++) {
                myString[i] = myString[i].trim();
                cpuUsageAsInt[i] = Integer.parseInt(myString[i]);
                //System.out.println("getCpuUsageStatistic-----"+cpuUsageAsInt[i]);
           }
           usage = cpuUsageAsInt[0]+cpuUsageAsInt[1];
           System.out.println("getCpuUsageStatistic-----"+usage); 
           return usage;
     }


And trying to incrase CPU usage by reducing sleeping time of running thread.

but, application COU usage is not increased.

My run method is like following::

public void run() {


           while (true) {
                try {

                     Thread.sleep(READ_INTERVAL);
                     totalUsage += cpuUpdate();
                     count++;
                     float cpuUsage = totalUsage / count;

                     if (count >= 10) {
                           if (cpuUsage >= desiredCpuUsage) {
                                System.out.println("cpu usage::%" + cpuUsage);

                                break;
                           } else {


                                System.out.println("cpu usage::%" + cpuUsage);
                         if(READ_INTERVAL / reducingFactor < 190)
                         {
                             if(cpuUsage / desiredCpuUsage< 0.2)
                             {
                                 reducingFactor = reducingFactor / 1.2;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.5)
                             {
                                 reducingFactor = reducingFactor / 1.5;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.6)
                             {
                                 reducingFactor = reducingFactor / 3.0;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.7)
                             {
                                 reducingFactor = reducingFactor / 4.0;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.75)
                             {
                                 reducingFactor = reducingFactor / 5.0;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.8)
                             {
                                 reducingFactor = reducingFactor / 6.0;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.85)
                             {
                                 reducingFactor = reducingFactor / 7.0;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.9)
                             {
                                 reducingFactor = reducingFactor / 9.0;
                             }
                             else if(cpuUsage / desiredCpuUsage < 0.95)
                             {
                                 reducingFactor = reducingFactor / 12.0;
                             }
                             else
                             {
                                 reducingFactor = reducingFactor / 15.0;
                             }
                         }
                         READ_INTERVAL-= reducingFactor;
                     }
                           cpuUsage=0;
                           count=0;
                           System.out.println("Read_interval" + READ_INTERVAL
                                     + "::cpu usage::%::" + cpuUsage);

                 }          



                           }


                catch (Exception e) {
                     e.printStackTrace();
                }  
           }
     }

please provide the solution and any technique to increase or decrease the usage of the cpu.
thanks in advance.

Answer 1

I would suggest to use some Math functions in a while-loop with Thread.sleep to cap it.

I am not sure if the Dalvik VM can be forced to accept the load or if it will optimise its runtime schedule to balance the load.

I just know that a lot of sin/cos functions create a pretty stable load that, in theory, should be easy to scale up and down by simply adding more or less calculations.

I just dont know how the VM handles this on a multi-core cpu, because if it suddenly moves the load off to the other core, the load on the first core drops or worse, changes all the time.

But i think its worth a try