Re: [PATCH 20/20] Get rid of the concept of hot/cold page freeing

Christoph Lameter
2009-02-25T18:43:22Z

On Wed, 25 Feb 2009, Mel Gorman wrote:

> It'd impact it for sure. Due to the non-temporal stores, I'm surprised
> there is any measurable impact from the patch. This has likely been the
> case since commit 0812a579c92fefa57506821fa08e90f47cb6dbdd. My reading of
> this (someone correct/enlighten) is that even if the data was cache hot,
> it is pushed out as a result of the non-temporal access.

A nontemporal store simply does not set the used flag for the cacheline.
So the cpu cache LRU will evict the cacheline sooner. Thats at least how
it works on I64.