Re: [PATCH 0/6] make memblock allocator utilize the node's fallback info

[Pingfan Liu]

On Tue, Feb 26, 2019 at 12:04 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>
> On Sun 24-02-19 20:34:03, Pingfan Liu wrote:
> > There are NUMA machines with memory-less node. At present page allocator builds the
> > full fallback info by build_zonelists(). But memblock allocator does not utilize
> > this info. And for memory-less node, memblock allocator just falls back "node 0",
> > without utilizing the nearest node. Unfortunately, the percpu section is allocated
> > by memblock, which is accessed frequently after bootup.
> >
> > This series aims to improve the performance of per cpu section on memory-less node
> > by feeding node's fallback info to memblock allocator on x86, like we do for page
> > allocator. On other archs, it requires independent effort to setup node to cpumask
> > map ahead.
>
> Do you have any numbers to tell us how much does this improve the
> situation?

Not yet. At present just based on the fact that we prefer to allocate
per cpu area on local node.

Thanks,
Pingfan