Re: [PATCH] arm64: add NUMA emulation support

From: Michal Hocko
Date: Fri Sep 07 2018 - 04:34:57 EST


On Thu 06-09-18 15:53:34, Shuah Khan wrote:
[...]
> A few critical allocations could be satisfied and root cgroup prevails. It is not the
> intent to have exclusivity at the expense of the kernel.

Well, it is not "few critical allocations". It can be a lot of
memory. Basically any GFP_KERNEL allocation. So how exactly you expect
this to work when you cannot estimate how much
memory will kernel eat?

>
> This feature will allow a way to configure cpusets on non-NUMA for workloads that can
> benefit from the reservation and isolation that is available within the constraints of
> exclusive cpuset policies.

AFAIR this was the first approach Google took for the memory isolation
and they moved over to memory cgroups. I would recommend to talk to
those guys bebfore you introduce potentially a lot of code that will not
really work for the workload you indend it for.
--
Michal Hocko
SUSE Labs