proc/meminfo: expose per-node balloon pages in node meminfo

Commit 835de37603ef ("meminfo: add a per node counter for balloon
drivers") added NR_BALLOON_PAGES and exposed it in /proc/meminfo.
However, the per-node view at /sys/devices/system/node/nodeX/meminfo was
not updated, even though the counter is already tracked per-node.

Add it to node_read_meminfo() so users can see balloon usage per NUMA node
without having to parse the raw vmstat file.

Link: https://lore.kernel.org/20260509005631.17183-1-hao.ge@linux.dev
Signed-off-by: Hao Ge <hao.ge@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 126f66aa2c3e84a65db0d521ea2856ff37fc86c0..f4d9a21cc24e90aa62ce2c7586178dacb2e7496e 100644 (file)
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -523,6 +523,7 @@ static ssize_t node_read_meminfo(struct device *dev,
 #ifdef CONFIG_UNACCEPTED_MEMORY
                             "Node %d Unaccepted:     %8lu kB\n"
 #endif
+                            "Node %d Balloon:        %8lu kB\n"
                             "Node %d GPUActive:      %8lu kB\n"
                             "Node %d GPUReclaim:     %8lu kB\n"
                             ,
@@ -559,6 +560,7 @@ static ssize_t node_read_meminfo(struct device *dev,
                             nid, K(sum_zone_node_page_state(nid, NR_UNACCEPTED))
 #endif
                             ,
+                            nid, K(node_page_state(pgdat, NR_BALLOON_PAGES)),
                             nid, K(node_page_state(pgdat, NR_GPU_ACTIVE)),
                             nid, K(node_page_state(pgdat, NR_GPU_RECLAIM))
                            );