"Research mission" precise control of process CPU utilization

First, CPU utilization rate calculation

CPU usage can be obtained through the top command or the/proc/<pid>/stat file

The following are the parameters for calculating CPU utilization:

pid=17184	process number
utime=45010
stime=4050	When the task is running at the kernel, the unit is jiffies
cutime=0	The time that all dead threads run in the user state, in jiffies
cstime=0	All the time that has died in the nuclear mentality, in jiffies

#参考python包psutil源码def cpu_percent (Self, interval=none): Def timer (): Return Time.time () * st1 = timer () PT1 = Self._proc.cpu_times () time.sleep (interval) st2 = timer () pt2 = Self._proc.cpu_times () Delta_proc = ( Pt2.user-pt1.user) + (pt2.system-pt1.system) Delta_time = St2-st1 try:cpu_percent = ((delta_proc/delt A_time) * except Zerodivisionerror:return 0.0

Single-Process CPU usage calculation:

① Each process snapshot is a 4-tuple (Utime, stime, Cutime, cstime);

② sampling two short enough time intervals for process snapshots

③ Compute CPU Usage for this process PCPU = 100* (processcputime2–processcputime1)/(TOTALCPUTIME2–TOTALCPUTIME1)

Second, the control principle

Assuming a given total time of 100ms, it is necessary to limit the CPU usage of process a to 25%. The execution time of process A is 25ms, and the remaining time is not allowed for process a to execute. The Sigstop/sigcont in the Linux interrupt signal allows the process to be paused and activated so that the program's CPU usage can be controlled at will.

#参考python包psutil源码def cpu_percent (Self, interval=none): Def timer (): Return Time.time () * st1 = timer () PT1 = Self._proc.cpu_times () time.sleep (interval) st2 = timer () pt2 = Self._proc.cpu_times () Delta_proc = ( Pt2.user-pt1.user) + (pt2.system-pt1.system) Delta_time = St2-st1 try:cpu_percent = ((delta_proc/delt A_time) * except Zerodivisionerror:return 0.0

Research tasks accurately control process CPU usage