Re: [PATCH v2] mm/balloon: expose per-node balloon pages in node meminfo

[Andrew Morton <akpm@linux-foundation.org>]

On Fri,  8 May 2026 17:47:36 +0800 Hao Ge <hao.ge@linux.dev> wrote:

> 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.
> 
> ...
>
> --- 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"
>  			     ,
>  			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
>  			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
> @@ -556,6 +557,8 @@ 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))
>  			    );
>  	len += hugetlb_report_node_meminfo(buf, len, nid);
>  	return len;

This was prepared against a kernel whcih didn't have 2232ba9c7931 ("mm:
add gpu active/reclaim per-node stat counters (v2)").  Which was added
in February, btw.

Please check my fixings:

--- a/drivers/base/node.c~mm-balloon-expose-per-node-balloon-pages-in-node-meminfo
+++ a/drivers/base/node.c
@@ -525,6 +525,7 @@ static ssize_t node_read_meminfo(struct
 #endif
 			     "Node %d GPUActive:      %8lu kB\n"
 			     "Node %d GPUReclaim:     %8lu kB\n"
+			     "Node %d Balloon:        %8lu kB\n"
 			     ,
 			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
 			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
@@ -560,7 +561,8 @@ static ssize_t node_read_meminfo(struct
 #endif
 			     ,
 			     nid, K(node_page_state(pgdat, NR_GPU_ACTIVE)),
-			     nid, K(node_page_state(pgdat, NR_GPU_RECLAIM))
+			     nid, K(node_page_state(pgdat, NR_GPU_RECLAIM)),
+			     nid, K(node_page_state(pgdat, NR_BALLOON_PAGES))
 			    );
 	len += hugetlb_report_node_meminfo(buf, len, nid);
 	return len;
_