On Thu, Jan 15, 2026 at 10:19:50AM +0100, David Hildenbrand (Red Hat) wrote:
> I started with wanting to remove the dependency of the balloon
> infrastructure on the page lock, but ended up performing various other
> cleanups, some of which I had on my todo list for years.
>
> This series heavily cleans up and simplifies our balloon infrastructure,
> including our balloon page migration functionality.
>
> With this series, we no longer make use of the page lock for PageOffline
> pages as part of the balloon infrastructure (preparing for memdescs
> where PageOffline pages won't have any such lock), and simplifies
> migration handling such that refcounting can more easily be adjusted
> later (long-term focus is for PageOffline pages to not have a refcount
> either).
>
> Plenty of related cleanups.
>
> Heavily compile-tested and heavily runtime-tested with virtio-balloon.
> PPC CMM and the VMware balloon are untested and I'd appreciate a helping
> hand from people that have suitable environments.
>
> Not CCing maintainers for the vmscan.c and migrate.c change as they
> are rather trivial and I don't want to patchbomb them.
besides MAINTAINERS thing:
Acked-by: Michael S. Tsirkin
> --
>
> This is based on mm/mm-unstable.
>
> v1 -> v2:
> * Rebased to latest mm/mm-unstable without any conflicts
> * Minor patch description/subject and comment fixups
> * Retested
>
> Cc: Andrew Morton
> Cc: Oscar Salvador
> Cc: Lorenzo Stoakes
> Cc: "Liam R. Howlett"
> Cc: Vlastimil Babka
> Cc: Mike Rapoport
> Cc: Suren Baghdasaryan
> Cc: Michal Hocko
> Cc: Jonathan Corbet
> Cc: Madhavan Srinivasan
> Cc: Michael Ellerman
> Cc: Nicholas Piggin
> Cc: Christophe Leroy
> Cc: Arnd Bergmann
> Cc: Greg Kroah-Hartman
> Cc: Jerrin Shaji George
> Cc: "Michael S. Tsirkin"
> Cc: Jason Wang
> Cc: Xuan Zhuo
> Cc: "Eugenio Pérez"
> Cc: Zi Yan
>
> David Hildenbrand (Red Hat) (23):
> vmw_balloon: adjust BALLOON_DEFLATE when deflating while migrating
> vmw_balloon: remove vmballoon_compaction_init()
> powerpc/pseries/cmm: remove cmm_balloon_compaction_init()
> mm/balloon_compaction: centralize basic page migration handling
> mm/balloon_compaction: centralize adjust_managed_page_count() handling
> vmw_balloon: stop using the balloon_dev_info lock
> mm/balloon_compaction: use a device-independent balloon (list) lock
> mm/balloon_compaction: remove dependency on page lock
> mm/balloon_compaction: make balloon_mops static
> mm/balloon_compaction: drop fs.h include from balloon_compaction.h
> drivers/virtio/virtio_balloon: stop using balloon_page_push/pop()
> mm/balloon_compaction: remove balloon_page_push/pop()
> mm/balloon_compaction: fold balloon_mapping_gfp_mask() into
> balloon_page_alloc()
> mm/balloon_compaction: move internal helpers to balloon_compaction.c
> mm/balloon_compaction: assert that the balloon_pages_lock is held
> mm/balloon_compaction: mark remaining functions for having proper
> kerneldoc
> mm/balloon_compaction: remove "extern" from functions
> mm/vmscan: drop inclusion of balloon_compaction.h
> mm: rename balloon_compaction.(c|h) to balloon.(c|h)
> mm/kconfig: make BALLOON_COMPACTION depend on MIGRATION
> mm: rename CONFIG_BALLOON_COMPACTION to CONFIG_BALLOON_MIGRATION
> mm: rename CONFIG_MEMORY_BALLOON -> CONFIG_BALLOON
> MAINTAINERS: move memory balloon infrastructure to "MEMORY MANAGEMENT
> - BALLOON"
>
> .../admin-guide/mm/memory-hotplug.rst | 8 +-
> Documentation/core-api/mm-api.rst | 2 +-
> MAINTAINERS | 12 +-
> arch/powerpc/platforms/pseries/Kconfig| 2 +-
> arch/powerpc/platforms/pseries/cmm.c | 53 +
> drivers/misc/Kconfig | 2 +-
> drivers/misc/vmw_balloon.c| 105 +++---
> drivers/virtio/Kconfig| 2 +-
> drivers/virtio/virtio_balloon.c | 64 ++
> include/linux/balloon.h | 77 +++
> include/linux/balloon_compaction.h| 160 ---
> include/linux/vm_event_item.h | 8 +-
> mm/Kconfig| 23 +--
> mm/Makefile | 2 +-
> mm/{balloon_compaction.c => balloon.c}| 194 +-
> mm/memory_hotplug.c | 4 +-
> mm/migrate.c | 2 +-
> mm/vmscan.c | 1 -
> mm/vmstat.c | 8 +-
> 19 files changed, 314 insertions(+), 415 deletions(-)
> create mode 100644 include/linux/balloon.h
> delete mode 100644 include/linux/balloon_compaction.h
> rename mm/{balloon_compaction.c => balloon.c} (59%)
>
>
> base-commit: f8ed52ac0cfbddff992bb9600941bfe51e1e385a
> --
> 2.52.0
