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

[Fabian Druschke]

Ahoy! Thanks for clarification! Didn't know it was intended behaviour.

We've encountered this issue specifically with this Realtek NIC on 
ShredOS due to lack of mlx5, mlx4 etc.

For NICs like ixgbe we didn't encounter this issue so i was thinking 
about a bug.

Thanks though!


BR,


On 16/02/2026 21:13, Andrew Lunn wrote:
> 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