Re: [RFC] cgroup TODOs
From: Peter Zijlstra <peterz@infradead.org>
Date: 2012-09-14 11:18:11
Also in:
lkml
From: Peter Zijlstra <peterz@infradead.org>
Date: 2012-09-14 11:18:11
Also in:
lkml
On Thu, 2012-09-13 at 13:58 -0700, Tejun Heo wrote:
The cpu ones handle nesting correctly - parent's accounting includes children's, parent's configuration affects children's unless explicitly overridden, and children's limits nest inside parent's.
The implementation has some issues with fixed point math limitations on deep hierarchies/large cpu count, but yes. Doing soft-float/bignum just isn't going to be popular I guess ;-) People also don't seem to understand that each extra cgroup carries a cost and that nested cgroups are more expensive still, even if the intermediate levels are mostly empty (libvirt is a good example of how not to do things). Anyway, I guess what I'm saying is that we need to work on the awareness of cost associated with all this cgroup nonsense, people seem to think its all good and free -- or not think at all, which, while depressing, seem the more likely option.