Re: A factoring algorithm

Phil Carmody wrote:
> You can tell if a the memory used in a critical part of your code
> is in the L1 cache by using performance monitoring counters, assuming
> your processor has such a feature. Just set them up to count memory
> accesses (or L1 hits) and L1 misses.
I have read the Intel documentation for my processor (Pentium 4), and I
can see in principle how to do this - program the counters using the
WDMSR instruction, and
read the values using the RDPMC instruction. However, how do you do it
in practice?
The WDMSR instruction can only be executed in the kernel as far as I
can see, so how do I program the counters using an application running
on Windows XP?
And since it looks hard work to write the code, does anyone have any
code available for this?

Chris
Received on Tue Jan 17 16:50:15 2006