On 18.01.2017 07:14, Eric Dumazet wrote:
From: Eric Dumazet <[email protected]>Commit 04aeb56a1732 ("net/mlx4_en: allocate non 0-order pages for RX ring with __GFP_NOMEMALLOC") added code that appears to be not needed at that time, since mlx4 never used __GFP_MEMALLOC allocations anyway. As using memory reserves is a must in some situations (swap over NFS or iSCSI), this patch adds this flag.
AFAIK __GFP_MEMALLOC is used for TX, not for RX: for allocations which are required by memory reclaimer to free some pages. Allocation RX buffers with __GFP_MEMALLOC is a straight way to depleting all reserves by flood from network.
Note that this driver does not reuse pages (yet) so we do not have to add anything else. Signed-off-by: Eric Dumazet <[email protected]> Cc: Konstantin Khlebnikov <[email protected]> Cc: Tariq Toukan <[email protected]> --- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index eac527e25ec902c2a586e9952272b9e8e599e2c8..e362f99334d03c0df4d88320977670015870dd9c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -706,7 +706,8 @@ static bool mlx4_en_refill_rx_buffers(struct mlx4_en_priv *priv, do { if (mlx4_en_prepare_rx_desc(priv, ring, ring->prod & ring->size_mask, - GFP_ATOMIC | __GFP_COLD)) + GFP_ATOMIC | __GFP_COLD | + __GFP_MEMALLOC)) break; ring->prod++; } while (--missing);
-- Konstantin
