[PATCH v3 0/5] cleanup page poisoning

[Vlastimil Babka]

Changes since v2 [2]

- rebase to next-20201113
- apply review feedback from David
- acks from David and Rafael (thanks!)

The first version was called "optimize handling of memory debugging parameters"
[1], changes are:

- apply review feedback
- drop former Patch 3
- add new patches 3-5, change name and cover letter of series

I have identified a number of issues and opportunities for cleanup with
CONFIG_PAGE_POISON and friends:
- interaction with init_on_alloc and init_on_free parameters depends on
  the order of parameters (Patch 1)
- the boot time enabling uses static key, but inefficienty (Patch 2)
- sanity checking is incompatible with hibernation (Patch 3)
- CONFIG_PAGE_POISONING_NO_SANITY can be removed now that we have init_on_free
  (Patch 4)
- CONFIG_PAGE_POISONING_ZERO can be most likely removed now that we have
  init_on_free (Patch 5)

[1] https://lore.kernel.org/r/20201026173358.14704-1-vbabka@xxxxxxx
[2] https://lore.kernel.org/linux-mm/20201103152237.9853-1-vbabka@xxxxxxx/

Vlastimil Babka (5):
  mm, page_alloc: do not rely on the order of page_poison and
    init_on_alloc/free parameters
  mm, page_poison: use static key more efficiently
  kernel/power: allow hibernation with page_poison sanity checking
  mm, page_poison: remove CONFIG_PAGE_POISONING_NO_SANITY
  mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO

 drivers/virtio/virtio_balloon.c |   4 +-
 include/linux/mm.h              |  54 +++++++++------
 include/linux/poison.h          |   4 --
 init/main.c                     |   2 +-
 kernel/power/hibernate.c        |   2 +-
 kernel/power/power.h            |   2 +-
 kernel/power/snapshot.c         |  14 +++-
 mm/Kconfig.debug                |  28 ++------
 mm/page_alloc.c                 | 112 ++++++++++++++++----------------
 mm/page_poison.c                |  56 ++--------------
 tools/include/linux/poison.h    |   6 +-
 11 files changed, 117 insertions(+), 167 deletions(-)

-- 
2.29.2