mm: rename balloon_compaction.(c|h) to balloon.(c|h)

Even without CONFIG_BALLOON_COMPACTION this infrastructure implements
basic list and page management for a memory balloon.

Link: https://lkml.kernel.org/r/20260119230133.3551867-21-david@kernel.org
Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Documentation/core-api/mm-api.rst

@@ -130,5 +130,5 @@ More Memory Management Functions
 .. kernel-doc:: mm/vmscan.c
 .. kernel-doc:: mm/memory_hotplug.c
 .. kernel-doc:: mm/mmu_notifier.c
-.. kernel-doc:: mm/balloon_compaction.c
+.. kernel-doc:: mm/balloon.c
 .. kernel-doc:: mm/huge_memory.c

MAINTAINERS

@@ -27546,9 +27546,9 @@ M:	David Hildenbrand <david@kernel.org>
 L:	virtualization@lists.linux.dev
 S:	Maintained
 F:	drivers/virtio/virtio_balloon.c
-F:	include/linux/balloon_compaction.h
+F:	include/linux/balloon.h
 F:	include/uapi/linux/virtio_balloon.h
-F:	mm/balloon_compaction.c
+F:	mm/balloon.c
 
 VIRTIO BLOCK AND SCSI DRIVERS
 M:	"Michael S. Tsirkin" <mst@redhat.com>

arch/powerpc/platforms/pseries/cmm.c

@@ -19,7 +19,7 @@
 #include <linux/stringify.h>
 #include <linux/swap.h>
 #include <linux/device.h>
-#include <linux/balloon_compaction.h>
+#include <linux/balloon.h>
 #include <asm/firmware.h>
 #include <asm/hvcall.h>
 #include <asm/mmu.h>

drivers/misc/vmw_balloon.c

@@ -29,7 +29,7 @@
 #include <linux/rwsem.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
-#include <linux/balloon_compaction.h>
+#include <linux/balloon.h>
 #include <linux/vmw_vmci_defs.h>
 #include <linux/vmw_vmci_api.h>
 #include <asm/hypervisor.h>

drivers/virtio/virtio_balloon.c

@@ -13,7 +13,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/module.h>
-#include <linux/balloon_compaction.h>
+#include <linux/balloon.h>
 #include <linux/oom.h>
 #include <linux/wait.h>
 #include <linux/mm.h>

include/linux/balloon.h

@@ -1,8 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /*
- * include/linux/balloon_compaction.h
- *
- * Common interface definitions for making balloon pages movable by compaction.
+ * Common interface for implementing a memory balloon, including support
+ * for migration of pages inflated in a memory balloon.
  *
  * Balloon page migration makes use of the general "movable_ops page migration"
  * feature.
@@ -35,8 +34,8 @@
  *
  * Copyright (C) 2012, Red Hat, Inc.  Rafael Aquini <aquini@redhat.com>
  */
-#ifndef _LINUX_BALLOON_COMPACTION_H
-#define _LINUX_BALLOON_COMPACTION_H
+#ifndef _LINUX_BALLOON_H
+#define _LINUX_BALLOON_H
 #include <linux/pagemap.h>
 #include <linux/page-flags.h>
 #include <linux/migrate.h>
@@ -75,4 +74,4 @@ static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
 	balloon->migratepage = NULL;
 	balloon->adjust_managed_page_count = false;
 }
-#endif /* _LINUX_BALLOON_COMPACTION_H */
+#endif /* _LINUX_BALLOON_H */

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-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o
+obj-$(CONFIG_MEMORY_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

mm/balloon.c

@@ -1,15 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * mm/balloon_compaction.c
- *
- * Common interface for making balloon pages movable by compaction.
+ * Common interface for implementing a memory balloon, including support
+ * for migration of pages inflated in a memory balloon.
  *
  * Copyright (C) 2012, Red Hat, Inc.  Rafael Aquini <aquini@redhat.com>
  */
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/export.h>
-#include <linux/balloon_compaction.h>
+#include <linux/balloon.h>
 
 /*
  * Lock protecting the balloon_dev_info of all devices. We don't really