Re: [PATCH] Move some variables into the "most_readonly" section??

[Andi Kleen]

On Tue, Jun 14, 2005 at 04:17:14PM -0700, Christoph Lameter wrote:
> On Wed, 15 Jun 2005, Andi Kleen wrote:
> 
> > > Hmm. No. The bigger cpu maps may benefit from cacheline alignment for 
> > > even for read access. 
> > 
> > Why? Can you please explain that. It doesn't make sense to me.
> 
> Its more likely to get a big piece of the array in a single 
> cacheline if the array starts at the beginning of a cacheline.
> 
> If these maps would start in the middle of a cacheline then additional 
> cacheline fetches may become necessary to scan an array etc.

But the CPUs do prefetching anyways for that. Do you have numbers
that this is actually worth it? 

-Andi
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