Re: [PATCH 3/4] perf cgroup: Add cgroup ID as a key of RB tree

[Peter Zijlstra]

On Mon, Apr 29, 2019 at 07:44:04AM -0700, kan.liang@xxxxxxxxxxxxxxx wrote:

> Add unique cgrp_id for each cgroup, which is composed by CPU ID and css
> subsys-unique ID.

*WHY* ?! that doesn't make any kind of sense.. In fact you mostly then
use the low word because most everything is already per CPU.