Re: [PATCH 24/27] mm, page_alloc: Remove fair zone allocation policy

[Vlastimil Babka]

On 06/09/2016 08:04 PM, Mel Gorman wrote:
> The fair zone allocation policy interleaves allocation requests between
> zones to avoid an age inversion problem whereby new pages are reclaimed
> to balance a zone. Reclaim is now node-based so this should no longer be
> an issue and the fair zone allocation policy is not free. This patch
> removes it.

I wonder if fair zone allocation had the side effect of preventing e.g. a small 
Normal zone to be almost fully occupied by long-lived unreclaimable allocations 
early in the kernel lifetime. So that might be one thing to watch out for. But 
otherwise I would agree it should be no longer needed with node-based reclaim.

> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>