On Tue, 2004-09-14 at 01:38, Marcelo Tosatti wrote: > Subject says it all, the following patch shrinks per_cpu_pages > struct from 24 to 16bytes, that makes the per CPU array containing > hot and cold "per_cpu_pages[2]" fit on 32byte cacheline. This structure > is often used so I bet this is a useful optimization. I'm not sure it's worth it. cachelines are 64 or 128 bytes nowadays and a short access costs you at least 1 extra cycle per access on several x86 cpus (byte and dword are cheap, short is not)