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

David Hildenbrand
2019-11-22T10:03:43Z

On 21.11.19 16:17, Pengfei Li wrote:
> Motivation
> ----------
> Currently if we want to iterate through all the nodes we have to
> traverse all the zones from the zonelist.
>
> So in order to reduce the number of loops required to traverse node,
> this series of patches modified the zonelist to nodelist.
>
> Two new macros have been introduced:
> 1) for_each_node_nlist
> 2) for_each_node_nlist_nodemask
>
>
> Benefit
> -------
> 1. For a NUMA system with N nodes, each node has M zones, the number
> of loops is reduced from N*M times to N times when traversing node.
>
> 2. The size of pg_data_t is much reduced.
>
>
> Test Result
> -----------
> Currently I have only performed a simple page allocation benchmark
> test on my laptop, and the results show that the performance of a
> system with only one node is almost unaffected.
>

So you are seeing no performance changes. I am wondering why do we need
this, then - because your motivation sounds like a performance
improvement? (not completely against this, just trying to understand the
value of this :) )

--

Thanks,

David / dhildenb