[PATCH -mm -V3 11/21] mm, THP, swap: Add sysfs interface to configure THP swapin

From: Huang Ying Swapin a THP as a whole isn't desirable at some situations. For example, for random access pattern, swapin a THP as a whole will inflate the reading greatly. So a sysfs interface: /sys/kernel/mm/transparent_hugepage/swapin_enabled is added to configure

[PATCH -mm -V3 11/21] mm, THP, swap: Add sysfs interface to configure THP swapin

From: Huang Ying Swapin a THP as a whole isn't desirable at some situations. For example, for random access pattern, swapin a THP as a whole will inflate the reading greatly. So a sysfs interface: /sys/kernel/mm/transparent_hugepage/swapin_enabled is added to configure it. Three options as