Re: [PATCH v2 22/23] mm: rename CONFIG_MEMORY_BALLOON -> CONFIG_BALLOON

Lorenzo Stoakes
2026-01-15T13:55:56Z

On Thu, Jan 15, 2026 at 10:20:12AM +0100, David Hildenbrand (Red Hat) wrote:
> Let's make it consistent with the naming of the files but also with the
> naming of CONFIG_BALLOON_MIGRATION.
>
> While at it, add a "/* CONFIG_BALLOON */".

Probably not relevant but cheap for me to share :) so grepped for
'memory_balloon' and saw:

include/uapi/linux/virtio_ids.h
44:#define VIRTIO_ID_MEMORY_BALLOON 13 /* virtio memory balloon */

This maybe relevant (I guess this isn't actually used anywhere?) though
interesting there is also VIRTIO_ID_BALLOON... hmm :)

The below doesn't look relevant at all.

drivers/virt/vboxguest/vmmdev.h
326:#define VMMDEV_MEMORY_BALLOON_CHUNK_SIZE (1048576)
327:#define VMMDEV_MEMORY_BALLOON_CHUNK_PAGES (1048576 / 4096)
355: u64 phys_page[VMMDEV_MEMORY_BALLOON_CHUNK_PAGES];

drivers/virt/vboxguest/vboxguest_core.c
278: pages = kmalloc_array(VMMDEV_MEMORY_BALLOON_CHUNK_PAGES,
286: req->pages = VMMDEV_MEMORY_BALLOON_CHUNK_PAGES;
288: for (i = 0; i < VMMDEV_MEMORY_BALLOON_CHUNK_PAGES; i++) {
333: req->pages = VMMDEV_MEMORY_BALLOON_CHUNK_PAGES;
335: for (i = 0; i < VMMDEV_MEMORY_BALLOON_CHUNK_PAGES; i++)
344: for (i = 0; i < VMMDEV_MEMORY_BALLOON_CHUNK_PAGES; i++)

>
> Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org>

Otherwise LGTM, so:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

> ---
> arch/powerpc/platforms/pseries/Kconfig | 2 +-
> drivers/misc/Kconfig | 2 +-
> drivers/virtio/Kconfig | 2 +-
> include/linux/vm_event_item.h | 4 ++--
> mm/Kconfig | 4 ++--
> mm/Makefile | 2 +-
> mm/vmstat.c | 4 ++--
> 7 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
> index 3e042218d6cd8..f7052b131a4c5 100644
> --- a/arch/powerpc/platforms/pseries/Kconfig
> +++ b/arch/powerpc/platforms/pseries/Kconfig
> @@ -120,7 +120,7 @@ config PPC_SMLPAR
> config CMM
> tristate "Collaborative memory management"
> depends on PPC_SMLPAR
> - select MEMORY_BALLOON
> + select BALLOON
> default y
> help
> Select this option, if you want to enable the kernel interface
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index d7d41b054b982..5cc79d1517af5 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -410,7 +410,7 @@ config DS1682
> config VMWARE_BALLOON
> tristate "VMware Balloon Driver"
> depends on VMWARE_VMCI && X86 && HYPERVISOR_GUEST
> - select MEMORY_BALLOON
> + select BALLOON
> help
> This is VMware physical memory management driver which acts
> like a "balloon" that can be inflated to reclaim physical pages
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 6db5235a7693d..ce5bc0d9ea287 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -112,7 +112,7 @@ config VIRTIO_PMEM
> config VIRTIO_BALLOON
> tristate "Virtio balloon driver"
> depends on VIRTIO
> - select MEMORY_BALLOON
> + select BALLOON
> select PAGE_REPORTING
> help
> This driver supports increasing and decreasing the amount
> diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
> index fca34d3473b6b..22a139f82d75f 100644
> --- a/include/linux/vm_event_item.h
> +++ b/include/linux/vm_event_item.h
> @@ -122,13 +122,13 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
> THP_SWPOUT,
> THP_SWPOUT_FALLBACK,
> #endif
> -#ifdef CONFIG_MEMORY_BALLOON
> +#ifdef CONFIG_BALLOON
> BALLOON_INFLATE,
> BALLOON_DEFLATE,
> #ifdef CONFIG_BALLOON_MIGRATION
> BALLOON_MIGRATE,
> #endif /* CONFIG_BALLOON_MIGRATION */
> -#endif
> +#endif /* CONFIG_BALLOON */
> #ifdef CONFIG_DEBUG_TLBFLUSH
> NR_TLB_REMOTE_FLUSH, /* cpu tried to flush others' tlbs */
> NR_TLB_REMOTE_FLUSH_RECEIVED,/* cpu received ipi for flush */
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 460a148d5b71a..8e23af521605e 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -593,7 +593,7 @@ config SPLIT_PMD_PTLOCKS
>
> #
> # support for memory balloon
> -config MEMORY_BALLOON
> +config BALLOON
> bool
>
> #
> @@ -601,7 +601,7 @@ config MEMORY_BALLOON
> config BALLOON_MIGRATION
> bool "Allow for balloon memory migration"
> default y
> - depends on MIGRATION && MEMORY_BALLOON
> + depends on MIGRATION && BALLOON
> help
> Allow for migration of pages inflated in a memory balloon such that
> they can be allocated from memory areas only available for movable
> diff --git a/mm/Makefile b/mm/Makefile
> index 1e31e0a528dc1..0d85b10dbdde4 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -122,7 +122,7 @@ obj-$(CONFIG_CMA) += cma.o
> obj-$(CONFIG_NUMA) += numa.o
> obj-$(CONFIG_NUMA_MEMBLKS) += numa_memblks.o
> obj-$(CONFIG_NUMA_EMU) += numa_emulation.o
> -obj-$(CONFIG_MEMORY_BALLOON) += balloon.o
> +obj-$(CONFIG_BALLOON) += balloon.o
> obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
> obj-$(CONFIG_PAGE_TABLE_CHECK) += page_table_check.o
> obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index e96a344ab5974..0f64c898f79f8 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1419,13 +1419,13 @@ const char * const vmstat_text[] = {
> [I(THP_SWPOUT)] = "thp_swpout",
> [I(THP_SWPOUT_FALLBACK)] = "thp_swpout_fallback",
> #endif
> -#ifdef CONFIG_MEMORY_BALLOON
> +#ifdef CONFIG_BALLOON
> [I(BALLOON_INFLATE)] = "balloon_inflate",
> [I(BALLOON_DEFLATE)] = "balloon_deflate",
> #ifdef CONFIG_BALLOON_MIGRATION
> [I(BALLOON_MIGRATE)] = "balloon_migrate",
> #endif /* CONFIG_BALLOON_MIGRATION */
> -#endif /* CONFIG_MEMORY_BALLOON */
> +#endif /* CONFIG_BALLOON */
> #ifdef CONFIG_DEBUG_TLBFLUSH
> [I(NR_TLB_REMOTE_FLUSH)] = "nr_tlb_remote_flush",
> [I(NR_TLB_REMOTE_FLUSH_RECEIVED)] = "nr_tlb_remote_flush_received",
> --
> 2.52.0
>