Re: [PATCH] shrink per_cpu_pages to fit 32byte cacheline

Arjan van de Ven
2004-09-14T06:10:04Z

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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)

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