Re: [tip:x86/mm] percpu: Introduce a read-mostly percpu API

Shaohua Li
2010-10-21T01:38:38Z

Hi hpa,
On Thu, Oct 21, 2010 at 07:06:59AM +0800, tip-bot for Shaohua Li wrote:
> [ hpa: moved it *after* the page-aligned section, for obvious
> reasons. ]
move it after page-aligned section can't guarantee to avoid cache false sharing.
we need:
. = ALIGN(CACHE_LINE_SIZE);
*(.data..percpu..readmostly)
. = ALIGN(CACHE_LINE_SIZE);
To make sure before/after readmostly section doesn't share cache line with
others. The headcache is some arch need L1_CACHE_SIZE and others need
(1 << INTERNODE_CACHE_SHIFT). We need change all ARCHs to make this happen.