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

[Eric Dumazet]

On Mon, Feb 16, 2026 at 7:53 PM Fabian Druschke <fabian@druschke.network> 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;

Control path prefers to wait a bit so that the NIC can be setup, this
could be used for instance to enable swaping over the network.

Note that this is GFP_KERNEL here, not GFP_KERNEL_ACCOUNT , OOM seems
reasonable here.