Messages in this thread | | | Date | Fri, 28 Aug 2009 12:50:08 +0530 | From | Balbir Singh <> | Subject | Re: [RFC][PATCH 1/5] memcg: change for softlimit. |
| |
* KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-28 13:23:21]:
> This patch tries to modify softlimit handling in memcg/res_counter. > There are 2 reasons in general. > > 1. soft_limit can use only against sub-hierarchy root. > Because softlimit tree is sorted by usage, putting prural groups > under hierarchy (which shares usage) will just adds noise and unnecessary > mess. This patch limits softlimit feature only to hierarchy root. > This will make softlimit-tree maintainance better. > > 2. In these days, it's reported that res_counter can be bottleneck in > massively parallel enviroment. We need to reduce jobs under spinlock. > The reason we check softlimit at res_counter_charge() is that any member > in hierarchy can have softlimit. > But by chages in "1", only hierarchy root has soft_limit. We can omit > hierarchical check in res_counter. > > After this patch, soft limit is avaliable only for root of sub-hierarchy. > (Anyway, softlimit for hierarchy children just makes users confused, hard-to-use) >
I need some time to digest this change, if the root is a hiearchy root then only root can support soft limits? I think the change makes it harder to use soft limits. Please help me understand better.
-- Balbir
| |