On 27.08.21 03:15, Rajesh Venkataraman via Xenomai wrote: > Hi, > For the linux pthreads we have used pthread_getcpuclockid() to get the > threads cpu time clock. Then periodically we do a clock_gettime() on this > timer to get all threads run time. Then do clock_gettime( CLOCK_MONOTONIC, > &ts ) to get the total system. Using the individual thread run time and > total run time, we calculate the percentage of CPU utilization for each > thread. Now we have moved the realtime thread to xenomai user space. > The clock_gettime() on a xenomai user thread returns an error. How do we > calculate what percentage of the CPU is utilized by the xenomai thread in > our Application? > > We also get the idle time of the CPU from the /proc/stat and calculate > the reserve percentage based on the total system time. Does linux idle time > also include xenomai run time? > > Is this correct method for calculating the CPU utilization percentage per > thread in a system/application with xenomai and linux pthreads running in a > single process? >
Xenomai does not support pthread_getcpuclockid for reading the consumed time of a thread. There are stats under /proc/xenomai/sched/acct, rtps uses them, but reading those require switching to Linux (if that is an issue for your use case). And there is an internal cobalt_thread_stat() syscall already, used only by some non-posix skins so far. I'm sitting on non-upstream changes to export the CPU usage of thread to userland without leaving RT, actually even without issuing a syscall. But those need rework in order to attach to some posix interface. What are your requirements on a statistic interface? Who is going to monitor who, and under which constraints? Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux
