Re: [PATCH v2 1/2] mm/vmalloc: fix numa spreading for large hash tables

[Chen Wandun]

在 2021/10/18 20:39, Matthew Wilcox 写道:
> On Mon, Oct 18, 2021 at 08:37:09PM +0800, Chen Wandun wrote:
> > Eric Dumazet reported a strange numa spreading info in [1], and found
> > commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") introduced
> > this issue [2].
>
> I think the root problem here is that we have two meanings for
> NUMA_NO_NODE.  I tend to read it as "The memory can be allocated from
> any node", but here it's used to mean "The memory should be spread over
> every node".  Should we split those out as -1 and -2?
Yes, the intent of NUMA_NO_NODE some time is confused.

Besides，I think NUMA_NO_NODE should consider mempolicy in
most cases in the kernel unless it point out explicitly memory
can be allocated without considering mempolicy.

> .