Re: [RFC 4/5] vmx_balloon: update the NR_BALLOON_PAGES state

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Mar 11, 2025 at 06:06:59PM -0600, Nico Pache wrote:
> Update the NR_BALLOON_PAGES counter when pages are added to or
> removed from the VMware balloon.
> 
> Signed-off-by: Nico Pache <npache@redhat.com>
> ---
>  drivers/misc/vmw_balloon.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
> index c817d8c21641..2c70b08c6fb3 100644
> --- a/drivers/misc/vmw_balloon.c
> +++ b/drivers/misc/vmw_balloon.c
> @@ -673,6 +673,8 @@ static int vmballoon_alloc_page_list(struct vmballoon *b,
>  
>  			vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_ALLOC,
>  						 ctl->page_size);
> +			mod_node_page_state(page_pgdat(page), NR_BALLOON_PAGES,
> +				vmballoon_page_in_frames(ctl->page_size));


same issue as virtio I think - this counts frames not pages.

>  		}
>  
>  		if (page) {
> @@ -915,6 +917,8 @@ static void vmballoon_release_page_list(struct list_head *page_list,
>  	list_for_each_entry_safe(page, tmp, page_list, lru) {
>  		list_del(&page->lru);
>  		__free_pages(page, vmballoon_page_order(page_size));
> +		mod_node_page_state(page_pgdat(page), NR_BALLOON_PAGES,
> +			-vmballoon_page_in_frames(page_size));
>  	}
>  
>  	if (n_pages)
> @@ -1129,7 +1133,6 @@ static void vmballoon_inflate(struct vmballoon *b)
>  
>  		/* Update the balloon size */
>  		atomic64_add(ctl.n_pages * page_in_frames, &b->size);
> -


unrelated change

>  		vmballoon_enqueue_page_list(b, &ctl.pages, &ctl.n_pages,
>  					    ctl.page_size);
>  
> -- 
> 2.48.1