Re: [PATCH v2 1/3] mm: Shuffle initial free memory

From: Dan Williams
Date: Tue Oct 09 2018 - 13:36:29 EST

On Tue, Oct 9, 2018 at 4:16 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> On Thu 04-10-18 09:51:37, Dan Williams wrote:
> > On Thu, Oct 4, 2018 at 12:48 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> > So the reason front-back randomization is not enough is due to the
> > in-order initial freeing of pages. At the start of that process
> > putting page1 in front or behind page0 still keeps them close
> > together, page2 is still near page1 and has a high chance of being
> > adjacent. As more pages are added ordering diversity improves, but
> > there is still high page locality for the low address pages and this
> > leads to no significant impact to the cache conflict rate. Patch3 is
> > enough to keep the entropy sustained over time, but it's not enough
> > initially.
> That should be in the changelog IMHO.

Fair enough, I'll fold that in when I rebase on top of -next.