Revert "lowmemorykiller.c: convert to use for_each_thread"

This reverts commit 63922acd1e269fa7968d4a42f73bf2163eb7f0c5.
Revert "introduce for_each_thread() to replace the buggy while_each_thread()"

This reverts commit f602c0fad2ce049881d238a87b13c54f7df4c95e.
Revert "mm, oom: base root bonus on current usage"

This reverts commit 4782de66a5e4f991aee9580128a41e407fcb7311.
Revert "mm, oom: prefer thread group leaders for display purposes"

This reverts commit 1ebee1569ae129ba227c281db32553be71bd907d.
Revert "oom_kill: add rcu_read_lock() into find_lock_task_mm()"

This reverts commit 2ef3f5a64a2c936e1a085d34daa2bbbac17a3b2b.
Revert "oom_kill: has_intersects_mems_allowed() needs rcu_read_lock()"

This reverts commit 02389db4cb7a121b9a08896e79c3cad29f3c7e4b.
Revert "oom_kill: change oom_kill.c to use for_each_thread()"

This reverts commit a886dc6ff2465e7d1a1462f84135ce541e69afc1.
Revert "mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR()."

This reverts commit 0d79a6c991f328ca478a3712741c7db8a1c8a4ad.
Revert "mm, oom: cleanup pagefault oom handler"

This reverts commit b87ff7fce523174961321532d2034034142c36a1.
Revert "oom: use N_MEMORY instead N_HIGH_MEMORY"

This reverts commit 43731278ee66423e159e0077d57d87c578623299.
Revert "mm, oom: allow exiting threads to have access to memory reserves"

This reverts commit e2d7f6a9a88e2fba558c10eea76e26da4bfae832.
Revert "Revert "lowmemorykiller: reduce swap significance by 1/2""

This reverts commit 86396a8143ed7517111a316a7f206ba27e986b20.
Revert "sched/fair: Optimize cgroup pick_next_task_fair()"

This reverts commit e7a025aafed18044887b09683c893f2caf5ea5a2.
Revert "sched/fair: Optimize find_busiest_queue()"

This reverts commit 00cf71c9f9f6d9b58448fc065c65dd943c011cc6.
Revert "lowmemorykiller: reduce swap significance by 1/2"

This reverts commit 85b50848874761c08cc2450a1e6b34be23bec0fe.
Revert "mm, memcg: move all oom handling to memcontrol.c"

This reverts commit 414ae6b3189d1e420b8ed7b70f858da743be925e.
Revert "mm, oom: reduce dependency on tasklist_lock"

This reverts commit e459eaecdd7e7fba186795b188b7dba0b9c4743f.
Revert "mm, memcg: introduce own oom handler to iterate only over its own threads"

This reverts commit 2cbd1f7bcadeeed729a1498c56965db8648a2671.
Revert "mm, oom: introduce helper function to process threads during scan"

This reverts commit fc87984340d51113454512d1860dc6c0cb3f05a0.
Revert "mm, oom: move declaration for mem_cgroup_out_of_memory to oom.h"

This reverts commit 58fc1a33ce974c80e7e5fdb49c7b7b6a99afad49.