Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers and writers of load_avg

[Waiman Long]

On 11/30/2015 05:09 PM, Peter Zijlstra wrote:
> On Mon, Nov 30, 2015 at 02:13:32PM -0500, Waiman Long wrote:
> > > This begs the question tough; why are you running a global load in a
> > > cgroup; and do we really need to update this for the root cgroup? It
> > > seems to me we don't need calc_tg_weight() for the root cgroup, it
> > > doesn't need to normalize its weight numbers.
> > >
> > > That is; isn't this simply a problem we should avoid?
> > I didn't use any cgroup in my test setup. Autogroup was enabled, though.
> > Booting up a 4.4-rc2 kernel caused sched_create_group() to be called 56
> > times.
> Yeah, can you kill autogroup and see if that helps? If not, we probably
> should add some code to avoid calculating things for the root group.

I will try that out tomorrow. However, SCHED_AUTOGROUP was enabled in 
the distribution kernels. So we still need to look at that with 
autogroup enabled.

Cheers,
Longman
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