FAILED: patch "[PATCH] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 0da2ba35c0d532ca0fe7af698b17d74c4d084b9a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026010548-hacked-transfer-1f00@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0da2ba35c0d532ca0fe7af698b17d74c4d084b9a Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@kernel.org>
Date: Tue, 21 Oct 2025 12:06:06 +0200
Subject: [PATCH] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating
 pages

Let's properly adjust BALLOON_MIGRATE like the other drivers.

Note that the INFLATE/DEFLATE events are triggered from the core when
enqueueing/dequeueing pages.

This was found by code inspection.

Link: https://lkml.kernel.org/r/20251021100606.148294-3-david@redhat.com
Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 688f5fa1c724..310dab4bc867 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -532,6 +532,7 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 
 	spin_lock_irqsave(&b_dev_info->pages_lock, flags);
 	balloon_page_insert(b_dev_info, newpage);
+	__count_vm_event(BALLOON_MIGRATE);
 	b_dev_info->isolated_pages--;
 	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
 

[PATCH 5.10.y 1/4] mm/balloon_compaction: make balloon page compaction callbacks static

[Sasha Levin]

From: Miaohe Lin <linmiaohe@huawei.com>

[ Upstream commit 504c1cabe325df65c18ef38365ddd1a41c6b591b ]

Since commit b1123ea6d3b3 ("mm: balloon: use general non-lru movable page
feature"), these functions are called via balloon_aops callbacks. They're
not called directly outside this file. So make them static and clean up
the relevant code.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Link: https://lore.kernel.org/r/20220125132221.2220-1-linmiaohe@huawei.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/balloon_compaction.h | 22 ----------------------
 mm/balloon_compaction.c            |  6 +++---
 2 files changed, 3 insertions(+), 25 deletions(-)

diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
index 338aa27e4773..edb7f6d41faa 100644
--- a/include/linux/balloon_compaction.h
+++ b/include/linux/balloon_compaction.h
@@ -80,12 +80,6 @@ static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
 
 #ifdef CONFIG_BALLOON_COMPACTION
 extern const struct address_space_operations balloon_aops;
-extern bool balloon_page_isolate(struct page *page,
-				isolate_mode_t mode);
-extern void balloon_page_putback(struct page *page);
-extern int balloon_page_migrate(struct address_space *mapping,
-				struct page *newpage,
-				struct page *page, enum migrate_mode mode);
 
 /*
  * balloon_page_insert - insert a page into the balloon's page list and make
@@ -155,22 +149,6 @@ static inline void balloon_page_delete(struct page *page)
 	list_del(&page->lru);
 }
 
-static inline bool balloon_page_isolate(struct page *page)
-{
-	return false;
-}
-
-static inline void balloon_page_putback(struct page *page)
-{
-	return;
-}
-
-static inline int balloon_page_migrate(struct page *newpage,
-				struct page *page, enum migrate_mode mode)
-{
-	return 0;
-}
-
 static inline gfp_t balloon_mapping_gfp_mask(void)
 {
 	return GFP_HIGHUSER;
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 26de020aae7b..829874221410 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -203,7 +203,7 @@ EXPORT_SYMBOL_GPL(balloon_page_dequeue);
 
 #ifdef CONFIG_BALLOON_COMPACTION
 
-bool balloon_page_isolate(struct page *page, isolate_mode_t mode)
+static bool balloon_page_isolate(struct page *page, isolate_mode_t mode)
 
 {
 	struct balloon_dev_info *b_dev_info = balloon_page_device(page);
@@ -217,7 +217,7 @@ bool balloon_page_isolate(struct page *page, isolate_mode_t mode)
 	return true;
 }
 
-void balloon_page_putback(struct page *page)
+static void balloon_page_putback(struct page *page)
 {
 	struct balloon_dev_info *b_dev_info = balloon_page_device(page);
 	unsigned long flags;
@@ -230,7 +230,7 @@ void balloon_page_putback(struct page *page)
 
 
 /* move_to_new_page() counterpart for a ballooned page */
-int balloon_page_migrate(struct address_space *mapping,
+static int balloon_page_migrate(struct address_space *mapping,
 		struct page *newpage, struct page *page,
 		enum migrate_mode mode)
 {
-- 
2.51.0

[PATCH 5.10.y 2/4] mm/balloon_compaction: we cannot have isolated pages in the balloon list

[Sasha Levin]

From: David Hildenbrand <david@redhat.com>

[ Upstream commit fb05f992b6bbb4702307d96f00703ee637b24dbf ]

Patch series "mm/migration: rework movable_ops page migration (part 1)",
v2.

In the future, as we decouple "struct page" from "struct folio", pages
that support "non-lru page migration" -- movable_ops page migration such
as memory balloons and zsmalloc -- will no longer be folios.  They will
not have ->mapping, ->lru, and likely no refcount and no page lock.  But
they will have a type and flags 🙂

This is the first part (other parts not written yet) of decoupling
movable_ops page migration from folio migration.

In this series, we get rid of the ->mapping usage, and start cleaning up
the code + separating it from folio migration.

Migration core will have to be further reworked to not treat movable_ops
pages like folios.  This is the first step into that direction.

This patch (of 29):

The core will set PG_isolated only after mops->isolate_page() was called.
In case of the balloon, that is where we will remove it from the balloon
list.  So we cannot have isolated pages in the balloon list.

Let's drop this unnecessary check.

Link: https://lkml.kernel.org/r/20250704102524.326966-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pé rez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/balloon_compaction.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 829874221410..02bcc22a6e77 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -93,12 +93,6 @@ size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
 		if (!trylock_page(page))
 			continue;
 
-		if (IS_ENABLED(CONFIG_BALLOON_COMPACTION) &&
-		    PageIsolated(page)) {
-			/* raced with isolation */
-			unlock_page(page);
-			continue;
-		}
 		balloon_page_delete(page);
 		__count_vm_event(BALLOON_DEFLATE);
 		list_add(&page->lru, pages);
-- 
2.51.0

[PATCH 5.10.y 3/4] mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

[Sasha Levin]

From: David Hildenbrand <david@redhat.com>

[ Upstream commit 15504b1163007bbfbd9a63460d5c14737c16e96d ]

Let's move the removal of the page from the balloon list into the single
caller, to remove the dependency on the PG_isolated flag and clarify
locking requirements.

Note that for now, balloon_page_delete() was used on two paths:

(1) Removing a page from the balloon for deflation through
    balloon_page_list_dequeue()
(2) Removing an isolated page from the balloon for migration in the
    per-driver migration handlers. Isolated pages were already removed from
    the balloon list during isolation.

So instead of relying on the flag, we can just distinguish both cases
directly and handle it accordingly in the caller.

We'll shuffle the operations a bit such that they logically make more
sense (e.g., remove from the list before clearing flags).

In balloon migration functions we can now move the balloon_page_finalize()
out of the balloon lock and perform the finalization just before dropping
the balloon reference.

Document that the page lock is currently required when modifying the
movability aspects of a page; hopefully we can soon decouple this from the
page lock.

Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pé rez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/pseries/cmm.c |  2 +-
 drivers/misc/vmw_balloon.c           |  3 +-
 drivers/virtio/virtio_balloon.c      |  4 +--
 include/linux/balloon_compaction.h   | 43 +++++++++++-----------------
 mm/balloon_compaction.c              |  3 +-
 5 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 45a3a3022a85..0507d3874c45 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -550,7 +550,6 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 
 	spin_lock_irqsave(&b_dev_info->pages_lock, flags);
 	balloon_page_insert(b_dev_info, newpage);
-	balloon_page_delete(page);
 	b_dev_info->isolated_pages--;
 	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
 
@@ -560,6 +559,7 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 	 */
 	plpar_page_set_active(page);
 
+	balloon_page_finalize(page);
 	/* balloon page list reference */
 	put_page(page);
 
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index b837e7eba5f7..be1004a31664 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -1810,8 +1810,7 @@ static int vmballoon_migratepage(struct balloon_dev_info *b_dev_info,
 	 * @pages_lock . We keep holding @comm_lock since we will need it in a
 	 * second.
 	 */
-	balloon_page_delete(page);
-
+	balloon_page_finalize(page);
 	put_page(page);
 
 	/* Inflate */
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 935ea2f3dac7..98e9d77911bc 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -796,15 +796,13 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,
 	tell_host(vb, vb->inflate_vq);
 
 	/* balloon's page migration 2nd step -- deflate "page" */
-	spin_lock_irqsave(&vb_dev_info->pages_lock, flags);
-	balloon_page_delete(page);
-	spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags);
 	vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE;
 	set_page_pfns(vb, vb->pfns, page);
 	tell_host(vb, vb->deflate_vq);
 
 	mutex_unlock(&vb->balloon_lock);
 
+	balloon_page_finalize(page);
 	put_page(page); /* balloon reference */
 
 	return MIGRATEPAGE_SUCCESS;
diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
index edb7f6d41faa..ee30fb134478 100644
--- a/include/linux/balloon_compaction.h
+++ b/include/linux/balloon_compaction.h
@@ -99,27 +99,6 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon,
 	list_add(&page->lru, &balloon->pages);
 }
 
-/*
- * balloon_page_delete - delete a page from balloon's page list and clear
- *			 the page->private assignement accordingly.
- * @page    : page to be released from balloon's page list
- *
- * Caller must ensure the page is locked and the spin_lock protecting balloon
- * pages list is held before deleting a page from the balloon device.
- */
-static inline void balloon_page_delete(struct page *page)
-{
-	__ClearPageOffline(page);
-	__ClearPageMovable(page);
-	set_page_private(page, 0);
-	/*
-	 * No touch page.lru field once @page has been isolated
-	 * because VM is using the field.
-	 */
-	if (!PageIsolated(page))
-		list_del(&page->lru);
-}
-
 /*
  * balloon_page_device - get the b_dev_info descriptor for the balloon device
  *			 that enqueues the given page.
@@ -143,12 +122,6 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon,
 	list_add(&page->lru, &balloon->pages);
 }
 
-static inline void balloon_page_delete(struct page *page)
-{
-	__ClearPageOffline(page);
-	list_del(&page->lru);
-}
-
 static inline gfp_t balloon_mapping_gfp_mask(void)
 {
 	return GFP_HIGHUSER;
@@ -156,6 +129,22 @@ static inline gfp_t balloon_mapping_gfp_mask(void)
 
 #endif /* CONFIG_BALLOON_COMPACTION */
 
+/*
+ * balloon_page_finalize - prepare a balloon page that was removed from the
+ *			   balloon list for release to the page allocator
+ * @page: page to be released to the page allocator
+ *
+ * Caller must ensure that the page is locked.
+ */
+static inline void balloon_page_finalize(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) {
+		__ClearPageMovable(page);
+		set_page_private(page, 0);
+	}
+	__ClearPageOffline(page);
+}
+
 /*
  * balloon_page_push - insert a page into a page list.
  * @head : pointer to list
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 02bcc22a6e77..c187b708477b 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -93,7 +93,8 @@ size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
 		if (!trylock_page(page))
 			continue;
 
-		balloon_page_delete(page);
+		list_del(&page->lru);
+		balloon_page_finalize(page);
 		__count_vm_event(BALLOON_DEFLATE);
 		list_add(&page->lru, pages);
 		unlock_page(page);
-- 
2.51.0

[PATCH 5.10.y 4/4] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages

[Sasha Levin]

From: David Hildenbrand <david@redhat.com>

[ Upstream commit 0da2ba35c0d532ca0fe7af698b17d74c4d084b9a ]

Let's properly adjust BALLOON_MIGRATE like the other drivers.

Note that the INFLATE/DEFLATE events are triggered from the core when
enqueueing/dequeueing pages.

This was found by code inspection.

Link: https://lkml.kernel.org/r/20251021100606.148294-3-david@redhat.com
Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/pseries/cmm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 0507d3874c45..de93f31768d3 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -550,6 +550,7 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 
 	spin_lock_irqsave(&b_dev_info->pages_lock, flags);
 	balloon_page_insert(b_dev_info, newpage);
+	__count_vm_event(BALLOON_MIGRATE);
 	b_dev_info->isolated_pages--;
 	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
 
-- 
2.51.0