ACT_MAX
if (bp->b_act_count > ACT_MAX - ACT_ADVANCE)
bp->b_act_count = ACT_MAX;
if (m->act_count > ACT_MAX)
m->act_count = ACT_MAX;
if (m->act_count > ACT_MAX)
m->act_count = ACT_MAX;
if (vm_pageout_stats_actcmp < ACT_MAX * 3 / 4)
if (p->act_count > ACT_MAX)
p->act_count = ACT_MAX;