perf_cgroup_from_task
perf_cgroup_from_task(prev, NULL) !=
perf_cgroup_from_task(next, NULL))
cgrp = perf_cgroup_from_task(task, NULL);
cpuctx->cgrp = perf_cgroup_from_task(current, ctx);
struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);