如何使用Linux获取滴答声中的时钟周期值？

Question

Taking the timestamp in linux is same as clock cycles in ticks for linux. I know how to get the timestamp but I dont now how to take the clock cycles in ticks. could someone tell me what is the difference between the two ?? could someone give me a small example for clock cycles in ticks ??

Looking forward for your reply.

extra : Am trying to add assembly instructions for timing in pisa architecture using simplescalar simulator. For my instructions i should access clock cycles and store it in the register.

Answer 1

Well, there are:

1. Ticks. Modern kernels don't use them .
2. Timestamp counter , this is what you may like to use for high-resolution time measurements, but you have to understand how to make unbiased measurements with it.
3. Clocks, portable clock_gettime , nanosecond-resolution, often good enough for everything.

If you want to get access to CPU performance registers, you can start with Intel® Performance Counter Monitor inside your programs .