Re: [PATCH v11 3/5] sched/core: uclamp: Propagate system defaults to root group

[Michal Koutný]

On Tue, Jul 16, 2019 at 03:34:17PM +0100, Patrick Bellasi 
<patrick.bell...@arm.com> wrote:
> > cpu_util_update_eff internally calls css_for_each_descendant_pre() so
> > this should be protected with rcu_read_lock().
> 
> Right, good catch! Will add in v12.
When I responded to your other patch, it occurred to me that since
cpu_util_update_eff goes writing down to child csses, it should take
also uclamp_mutex here to avoid race with direct cgroup attribute
writers.