[PATCH v2 0/4] Make balloon drivers memory changes known to the rest of the kernel

[Alexander Atanasov <alexander.atanasov@xxxxxxxxxxxxx>]

Currently balloon drivers (Virtio,XEN, HyperV, VMWare, ...)
inflate and deflate the guest memory size but there is no
way to know how much the memory size is changed by them.

A common use of the ballooning is to emulate [1]
hot plug and hot unplug - due to the complexity of the later.
Hotplug has a notifier and one can also check the updated
memory size.

To improve this add InflatedTotal and InflatedFree
to /proc/meminfo and implement a balloon notifier.

Amount of inflated memory can be used:
 - si_meminfo(..) users can improve calculations
 - adjust cache/buffer sizes 
 - adjust object/connection limits
 - as a hint for the oom a killer
 - by user space software that monitors memory pressure

Patches for the other balloon drivers will be done next.

Alexander Atanasov (4):
  Make place for common balloon code
  Enable balloon drivers to report inflated memory
  Display inflated memory to users
  drivers: virtio: balloon - update inflated memory

 Documentation/filesystems/proc.rst            |  6 +++
 MAINTAINERS                                   |  4 +-
 arch/powerpc/platforms/pseries/cmm.c          |  2 +-
 drivers/misc/vmw_balloon.c                    |  2 +-
 drivers/virtio/virtio_balloon.c               |  7 +++-
 fs/proc/meminfo.c                             | 10 +++++
 ...{balloon_compaction.h => balloon_common.h} | 20 +++++++++-
 mm/Makefile                                   |  2 +-
 mm/{balloon_compaction.c => balloon_common.c} | 38 ++++++++++++++++++-
 mm/migrate.c                                  |  2 +-
 mm/vmscan.c                                   |  2 +-
 11 files changed, 84 insertions(+), 11 deletions(-)
 rename include/linux/{balloon_compaction.h => balloon_common.h} (90%)
 rename mm/{balloon_compaction.c => balloon_common.c} (89%)

Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Wei Liu <wei.liu@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: pv-drivers@xxxxxxxxxx
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
Cc: linux-hyperv@xxxxxxxxxxxxxxx
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx


-- 
2.31.1