Re: scheduler scalability - cgroups, cpusets and load-balancing

Peter Zijlstra
2008-01-29T10:58:43Z

Here I go, talking to myself..

On Tue, 2008-01-29 at 10:53 +0100, Peter Zijlstra wrote:

> My thoughts were to make stronger use of disjoint cpu-sets. cgroups and
> cpusets are related, in that cpusets provide a property to a cgroup.
> However, load_balance_monitor()'s interaction with sched domains
> confuses me - it might DTRT, but I can't tell.
>
> [ It looks to me it balances a group over the largest SD the current cpu
> has access to, even though that might be larger than the SD associated
> with the cpuset of that particular cgroup. ]

Hmm, with a bit more thought I think that does indeed DTRT. Because, if
the cpu belongs to a disjoint cpuset, the highest sd (with
load-balancing enabled) would be that. Right?

[ Just a bit of a shame we have all cgroups represented on each cpu. ]

Also, might be a nice idea to split the daemon up if there are indeed
disjoint sets - currently there is only a single daemon which touches
the whole system.