Re: [PATCH 2/2] mm: memcontrol: switch to native NR_VMALLOC vmstat counter

[Uladzislau Rezki <urezki@gmail.com>]

On Fri, Feb 20, 2026 at 02:10:35PM -0500, Johannes Weiner wrote:
> Eliminates the custom memcg counter and results in a single,
> consolidated accounting call in vmalloc code.
> 
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
> ---
>  include/linux/memcontrol.h |  1 -
>  mm/memcontrol.c            |  4 ++--
>  mm/vmalloc.c               | 16 ++++------------
>  3 files changed, 6 insertions(+), 15 deletions(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 67f154de10bc..c7cc4e50e59a 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -35,7 +35,6 @@ enum memcg_stat_item {
>  	MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
>  	MEMCG_SOCK,
>  	MEMCG_PERCPU_B,
> -	MEMCG_VMALLOC,
>  	MEMCG_KMEM,
>  	MEMCG_ZSWAP_B,
>  	MEMCG_ZSWAPPED,
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 129eed3ff5bb..fef5bdd887e0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -317,6 +317,7 @@ static const unsigned int memcg_node_stat_items[] = {
>  	NR_SHMEM_THPS,
>  	NR_FILE_THPS,
>  	NR_ANON_THPS,
> +	NR_VMALLOC,
>  	NR_KERNEL_STACK_KB,
>  	NR_PAGETABLE,
>  	NR_SECONDARY_PAGETABLE,
> @@ -339,7 +340,6 @@ static const unsigned int memcg_stat_items[] = {
>  	MEMCG_SWAP,
>  	MEMCG_SOCK,
>  	MEMCG_PERCPU_B,
> -	MEMCG_VMALLOC,
>  	MEMCG_KMEM,
>  	MEMCG_ZSWAP_B,
>  	MEMCG_ZSWAPPED,
> @@ -1359,7 +1359,7 @@ static const struct memory_stat memory_stats[] = {
>  	{ "sec_pagetables",		NR_SECONDARY_PAGETABLE		},
>  	{ "percpu",			MEMCG_PERCPU_B			},
>  	{ "sock",			MEMCG_SOCK			},
> -	{ "vmalloc",			MEMCG_VMALLOC			},
> +	{ "vmalloc",			NR_VMALLOC			},
>  	{ "shmem",			NR_SHMEM			},
>  #ifdef CONFIG_ZSWAP
>  	{ "zswap",			MEMCG_ZSWAP_B			},
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index a49a46de9c4f..8773bc0c4734 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -3446,9 +3446,6 @@ void vfree(const void *addr)
>  
>  	if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
>  		vm_reset_perms(vm);
> -	/* All pages of vm should be charged to same memcg, so use first one. */
> -	if (vm->nr_pages && !(vm->flags & VM_MAP_PUT_PAGES))
> -		mod_memcg_page_state(vm->pages[0], MEMCG_VMALLOC, -vm->nr_pages);
>  	for (i = 0; i < vm->nr_pages; i++) {
>  		struct page *page = vm->pages[i];
>  
> @@ -3458,7 +3455,7 @@ void vfree(const void *addr)
>  		 * can be freed as an array of order-0 allocations
>  		 */
>  		if (!(vm->flags & VM_MAP_PUT_PAGES))
> -			dec_node_page_state(page, NR_VMALLOC);
> +			mod_lruvec_page_state(page, NR_VMALLOC, -1);
>  		__free_page(page);
>  		cond_resched();
>  	}
> @@ -3649,7 +3646,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
>  			continue;
>  		}
>  
> -		mod_node_page_state(page, NR_VMALLOC, 1 << large_order);
> +		mod_lruvec_page_state(page, NR_VMALLOC, 1 << large_order);
>  
>  		split_page(page, large_order);
>  		for (i = 0; i < (1U << large_order); i++)
> @@ -3696,7 +3693,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
>  							pages + nr_allocated);
>  
>  			for (i = nr_allocated; i < nr_allocated + nr; i++)
> -				inc_node_page_state(pages[i], NR_VMALLOC);
> +				mod_lruvec_page_state(pages[i], NR_VMALLOC, 1);
>  
>  			nr_allocated += nr;
>  
> @@ -3722,7 +3719,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
>  		if (unlikely(!page))
>  			break;
>  
> -		mod_node_page_state(page, NR_VMALLOC, 1 << order);
> +		mod_lruvec_page_state(page, NR_VMALLOC, 1 << order);
>  
>  		/*
>  		 * High-order allocations must be able to be treated as
> @@ -3866,11 +3863,6 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
>  			vmalloc_gfp_adjust(gfp_mask, page_order), node,
>  			page_order, nr_small_pages, area->pages);
>  
> -	/* All pages of vm should be charged to same memcg, so use first one. */
> -	if (gfp_mask & __GFP_ACCOUNT && area->nr_pages)
> -		mod_memcg_page_state(area->pages[0], MEMCG_VMALLOC,
> -				     area->nr_pages);
> -
>  	/*
>  	 * If not enough pages were obtained to accomplish an
>  	 * allocation request, free them via vfree() if any.
> -- 
> 2.53.0
> 
LGTM:

Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>