Re: [mm][PATCH 0/4] Memory cgroup hierarchy introduction

KAMEZAWA Hiroyuki
2008-11-04T00:15:56Z

On Sun, 02 Nov 2008 00:18:12 +0530
Balbir Singh <balbir@linux.vnet.ibm.com> wrote:

> This patch follows several iterations of the memory controller hierarchy
> patches. The hardwall approach by Kamezawa-San[1]. Version 1 of this patchset
> at [2].
>
> The current approach is based on [2] and has the following properties
>
> 1. Hierarchies are very natural in a filesystem like the cgroup filesystem.
> A multi-tree hierarchy has been supported for a long time in filesystems.
> When the feature is turned on, we honor hierarchies such that the root
> accounts for resource usage of all children and limits can be set at
> any point in the hierarchy. Any memory cgroup is limited by limits
> along the hierarchy. The total usage of all children of a node cannot
> exceed the limit of the node.
> 2. The hierarchy feature is selectable and off by default
> 3. Hierarchies are expensive and the trade off is depth versus performance.
> Hierarchies can also be completely turned off.
>
> The patches are against 2.6.28-rc2-mm1 and were tested in a KVM instance
> with SMP and swap turned on.
>

As first impression, I think hierarchical LRU management is not good...means
not fair from viewpoint of memory management.
I'd like to show some other possible implementation of
try_to_free_mem_cgroup_pages() if I can.

Anyway, I have to merge this with mem+swap controller.

Thanks,
-Kame