Aligning to cache line and knowing the cache line size

Question

To prevent false sharing, I want to align each element of an array to a cache line. So first I need to know the size of a cache line, so I assign each element that amount of

Answer 1

I am using Linux and 8-core x86 platform. First how do I find the cache line size.

$ getconf LEVEL1_DCACHE_LINESIZE
64

Pass the value as a macro definition to the compiler.

$ gcc -DLEVEL1_DCACHE_LINESIZE=`getconf LEVEL1_DCACHE_LINESIZE` ...

At run-time sysconf(_SC_LEVEL1_DCACHE_LINESIZE) can be used to get L1 cache size.