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

[Lorenzo Stoakes <lorenzo.stoakes@oracle.com>]

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
>