Benchmarking C code - Flush Cache

Question

I am wondering if it is possible to force a cache flush within c using linux x86. I have read several answers answering how to do this within the shell or using asm/cache.h (requiring me to write a linux module...)

I am using the PAPI library which allows me to get very close to the exact number of clock cycles that a given block of code takes to execute. However, since I want to time some extremely short functions I need to run the functions many times for accurate statistics (the timing function call takes longer than the code within the blocks takes to execute). By running the code multiple times the cache is speeding up the execution of successive calls of the same block of code and I would like to prevent this!

Answer 1

I don't Know any standard way to do this other than loading other thing to the cache. My usual workaround is simply process something large enough to "cool down" the cache, say a matrix multiplication.