PSWPOUT
mem_data->pswpout = ev[PSWPOUT];
pages_to_bytes(events[PSWPOUT]));
PSWPOUT,
count_memcg_folio_events(folio, PSWPOUT, folio_nr_pages(folio));
count_vm_events(PSWPOUT, folio_nr_pages(folio));
[I(PSWPOUT)] = "pswpout",