Re: [PATCH] r8169: avoid OOM when allocating RX buffers

[Andrew Lunn]

On Mon, Feb 16, 2026 at 07:52:45PM +0100, Fabian Druschke wrote:
> From: Fabian Druschke <fdruschke@xxxxxxxxxxx>
> 
> r8169 allocates order-2 pages for RX buffers during rtl_open(). Under heavy
> memory fragmentation this allocation may trigger the global OOM killer,
> causing unrelated user processes to be killed.
> 
> Use a GFP mask that avoids OOM killer invocation so the allocation can fail
> gracefully and rtl_open() returns -ENOMEM instead.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Fabian Druschke <fdruschke@xxxxxxxxxxx>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 3507c2e28110..3525e889ec1c 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -3952,7 +3952,8 @@ static struct page *rtl8169_alloc_rx_data(struct rtl8169_private *tp,
>  	dma_addr_t mapping;
>  	struct page *data;
>  
> -	data = alloc_pages_node(node, GFP_KERNEL, get_order(R8169_RX_BUF_SIZE));
> +	gfp_t gfp = GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
> +	data = alloc_pages_node(node, gfp, get_order(R8169_RX_BUF_SIZE));
>  	if (!data)
>  		return NULL;

~/linux/drivers/net$ grep -r alloc_pages_node
ethernet/chelsio/cxgb4/cxgb4_main.c:		newpage = alloc_pages_node(node, __GFP_NOWARN | GFP_KERNEL |
ethernet/chelsio/cxgb4/sge.c:		pg = alloc_pages_node(node, gfp | __GFP_COMP, s->fl_pg_order);
ethernet/chelsio/cxgb4/sge.c:		pg = alloc_pages_node(node, gfp, 0);
ethernet/amd/xgbe/xgbe-desc.c:		pages = alloc_pages_node(node, gfp, order);
ethernet/fungible/funcore/fun_queue.c:		rqinfo->page = alloc_pages_node(node, GFP_KERNEL, 0);
ethernet/fungible/funeth/funeth_rx.c:	p = __alloc_pages_node(node, gfp | __GFP_NOWARN, 0);
ethernet/mellanox/mlx5/core/pagealloc.c:	page = alloc_pages_node(nid, GFP_HIGHUSER, 0);
ethernet/mellanox/mlx5/core/en_main.c:		struct page *page = alloc_pages_node(node, GFP_KERNEL, 0);
ethernet/mellanox/mlx4/icm.c:	page = alloc_pages_node(node, gfp_mask, order);
ethernet/realtek/r8169_main.c:	data = alloc_pages_node(node, GFP_KERNEL, get_order(R8169_RX_BUF_SIZE));
ethernet/google/gve/gve_main.c:	*page = alloc_pages_node(priv->numa_node, gfp_flags, 0);
ethernet/google/gve/gve_rx.c:			struct page *page = alloc_pages_node(priv->numa_node,
ethernet/google/gve/gve_rx_dqo.c:	struct page *page = alloc_pages_node(rx->gve->numa_node, GFP_ATOMIC, 0);
ethernet/hisilicon/hns3/hns3_enet.c:	page = alloc_pages_node(dev_to_node(ring_to_dev(ring)),

:~/linux/drivers/net$ grep -r __GFP_RETRY_MAYFAIL
veth.c:			    GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);

What makes the r8169 special?

     Andrew