Re: [RFC v1 00/19] Modify zonelist to nodelist v1

[David Hildenbrand]

On 22.11.19 16:53, Christopher Lameter wrote:
> On Fri, 22 Nov 2019, Pengfei Li wrote:
> 
>> I am sorry that I did not make it clear. I want to express this series
>> of patches will benefit NUMA systems with multiple nodes.
> 
> Ok but that benefit needs to be quantified somehow.
> 
>> The main benefit is that it will be more efficient when traversing all
>> nodes (for example when performing page reclamation).
> 
> And you loose the prioritization of allocations through these different
> zones. We create zonelists with a certain sequence of the zones in
> order to prefer allocations from certain zones. This is in particular
> important for the smaller DMA zones which may be easily exhausted.
> 

That's an important point also when MOVABLE is in place. You really
don't want to go to random other zones before considering all MOVABLE
zones. Same with DMA and NORMAL.

-- 

Thanks,

David / dhildenb