Intel Core Duo Hardware Performance Counter

Question

I read that there are AMD processors that allow you to measure the number of cache hits and misses. I am wondering if such a feature is available on Intel Core Duo computers or if they do not yet support it.

Answer 1

Yes, with the ancient Pentium Pro there are many counters of hardware performance.

Oprofile and perf on Linux, Vtune on Linux / Windows, Shark on MacOSX can use them.

All counters are listed in the Intel Architecture Documentation (Volume 3B, Chapter 30, List in Appendix A): http://www.intel.com/products/processor/manuals/

Even Atom has some performance registers.

One of the good lists for different CPUs is here http://oprofile.sourceforge.net/docs/

Answer 2

If you are working on Linux, Columbia University has an interesting library called LiMiT , which can quickly read performance counters and virtualize them to avoid problems with running and stopped processes, move between processors, etc. Currently, I am in a class with a developer, although I myself have no relation to the project.

Answer 3

This document certainly assumes that Intel Core Duo processors can provide the information you need. I assume that a site search on the Intel site will also be useful.

Answer 4

I personally use the timestamp counter through an assembly that executes the rdtsc statement. Then I get an unsigned 64-bit integer containing the number of internal clock cycles that have passed since the processor was turned on. The difference between two reads is the number of code cycles required to execute a piece of code between them. Accessing instructions for reading the cache can be implemented in the same way.

It’s hard for me to understand what conclusions should be drawn from reading cache counters without a time frame for communication. This time interval should not be too long, or a task switch or interrupt can affect the value.

According to Microsoft, an rdtsc device may be inaccurate if the processor has a down-throttle function (to reduce energy consumption) that must be taken into account (or turned off!).