如何知道进程的空闲时间

Question

Probably this question is a duplicate.but i was not able to find. How do i check that how much time a process has been in idle state.

my actual problem:

I have a process which runs on solaris unix X86 server. In our test servers its finishes its job in 4 hours.But in our client servers its taking more than than 10 hours.I checked in the client server and found that the configuration in our client server is different from our test server.for eg: number of virtual processors in testserver are-24 but in client server are only 8. and processor speed also differs.

I suspect it is because of the configuration that the process is not actually getting the cpu time and i suspect that it is idle for most of the time.

But i just want to know how much time the process is idle.Is there any specific way to do this?The process is written in c++ so i am also tagging this as c++

Answer 1

nmon is available at www.sourceforge.net but there are plenty of tools

Your "idle time" may be context switching if your app is a cpu beast. Without instrumenting the code, to get an idea of what is going on, try pbind to lock the process to a single cpu, then run your app

time myapp

Your real time (wall time) and the cpu times for user and kernel will be given. Since the process is constrained the wall time may be longer, but this will give you total cpu for parent, LWP's, and children.

Beyond that you can instrument the code and report generally finer grained information by using procfs (procfs.h) to get cpu information. You can compile to enable profiling, then see where your bottlenecks are as well if deem the cpu consumption is too high.

Answer 2

been in idle state

I'm not sure what you mean by "idle". Do you mean "blocked". Comparing the total of user+system CPU to the elapsed time will give you an approximation of that, assuming your computer is not heavily loaded.