[v2,2/4] balloon_compaction: update the NR_BALLOON_PAGES state

Commit Message

Nico Pache March 14, 2025, 9:37 p.m. UTC

Update the NR_BALLOON_PAGES counter when pages are added or removed using
the balloon compaction interface.

The virtio, Vmware, and pseries-cmm balloon drivers utilize the
balloon_compaction interface to allocate and free balloon pages. Other
balloon drivers will have to maintain this counter manually.

Signed-off-by: Nico Pache <[e-mail]>
---
 mm/balloon_compaction.c | 2 ++
 1 file changed, 2 insertions(+)

Patch

diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 6597ebea8ae2..d3e00731e262 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -24,6 +24,7 @@  static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info,
 	balloon_page_insert(b_dev_info, page);
 	unlock_page(page);
 	__count_vm_event(BALLOON_INFLATE);
+	inc_node_page_state(page, NR_BALLOON_PAGES);
 }
 
 /**
@@ -103,6 +104,7 @@  size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
 		__count_vm_event(BALLOON_DEFLATE);
 		list_add(&page->lru, pages);
 		unlock_page(page);
+		dec_node_page_state(page, NR_BALLOON_PAGES);
 		n_pages++;
 	}
 	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);