PGFAULT
mem_data->pgfault = ev[PGFAULT];
update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]);
PGFAULT,
PGFAULT,
count_vm_event(PGFAULT);
count_memcg_event_mm(mm, PGFAULT);
[I(PGFAULT)] = "pgfault",
memcg_query.pgfault = bpf_mem_cgroup_vm_events(memcg, PGFAULT);