I've been trying to move away from using the PerformanceCounter class for monitoring a process's CPU usage since it seems it requires a decent amount of CPU when the process count gets decently high (when monitoring a lot of processes).
My first approach was to take the WMI route using Win32_PerfFormattedData_PerfOS_Processor class and the PercentProcessorTime property, but there seems to be an issue when trying to calculate the CPU usage over multiple cores (the max value it's returning is 100% making it impossible to divide it based on the CPU core count, resulting in inaccurate results).
So finally I decided to use the Process's class TotalProcessorTime property. Sadly I am unsure how to calculate the percentage of the total CPU usage used by the Process based the value. I know that I should subtract the current PercentProcessorTime value from a previous PercentProcessorTime value to get how much time the processor spent on the process within a certain time limit but I am unsure how to continue from there.
Thanks in advance.
class GetCPUUsage
{
static TimeSpan start;
public static double CPUUsageTotal
{
get;
private set;
}
public static double CPUUsageLastMinute
{
get;
private set;
}
static TimeSpan oldCPUTime = new TimeSpan(0);
static DateTime lastMonitorTime = DateTime.UtcNow;
public static DateTime StartTime = DateTime.UtcNow;
// Call it once everything is ready
static void OnStartup()
{
start = Process.GetCurrentProcess().TotalProcessorTime;
}
// Call this every 30 seconds
static void CallCPU()
{
TimeSpan newCPUTime = Process.GetCurrentProcess().TotalProcessorTime - start;
CPUUsageLastMinute = (newCPUTime - oldCPUTime).TotalSeconds / (Environment.ProcessorCount * DateTime.UtcNow.Subtract(lastMonitorTime).TotalSeconds);
lastMonitorTime = DateTime.UtcNow;
CPUUsageTotal = newCPUTime.TotalSeconds / (Environment.ProcessorCount * DateTime.UtcNow.Subtract(StartTime).TotalSeconds);
oldCPUTime = newCPUTime;
}
}
class GetCPUInfo
{
public static string GetInfoMinute()
{
return String.Format("{0:0.0}", GetCPUUsage.CPUUsageLastMinute * 100);
}
public static string GetInfoTotal()
{
return String.Format("{0:0.0}", GetCPUUsage.CPUUsageTotal * 100);
}
}