getvmusage
if (getvmusage(flags, opts.o_interval, NULL, &nres) != 0)
ret = getvmusage(flags, opts.o_interval, results, &nres);
if (getvmusage(flags, my_zone_only ? 0 : rcfg.rcfg_rss_sample_interval,
extern int getvmusage(uint_t flags, time_t age, vmusage_t *buf, size_t *nres);