On Fri, 22 Nov 2019 15:53:57 +0000 (UTC)
Christopher Lameter <cl@xxxxxxxxx> 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.
>
Thanks for your comments.
Yes, I will add detailed performance test data in v2.
> > 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.
Sorry, I forgot to mention that the information about the zones that
are available to the node is still there.
The old for_each_zone_zonelist has been replaced with
for_each_zone_nodelist.
I will add some key implementation details in v2.
> 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.
>
I'm not sure if I understand what you mean, but since commit
c9bff3eebc09 ("mm, page_alloc: rip out ZONELIST_ORDER_ZONE"), the
zonelist is always in "Node" order, so building the nodelist is fine.
--
Pengfei
