PERF_FLAG_PID_CGROUP
if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
if (flags & PERF_FLAG_PID_CGROUP)
PERF_FLAG_PID_CGROUP |\
#ifndef PERF_FLAG_PID_CGROUP
evsel->open_flags |= PERF_FLAG_PID_CGROUP;