Re: [PATCH net] mlx4: reduce OOM risk on arches with large pages
From: Tariq Toukan <hidden>
Date: 2017-02-20 08:44:22
On 18/02/2017 8:34 PM, Eric Dumazet wrote:
quoted hunk ↗ jump to hunk
From: Eric Dumazet <edumazet@google.com> Since mlx4 NIC are used on PowerPC with 64K pages, we need to adapt MLX4_EN_ALLOC_PREFER_ORDER definition. Otherwise, a fragment sitting in an out of order TCP queue can hold 0.5 Mbytes and it is a serious OOM risk. Fixes: 51151a16a60f ("mlx4: allow order-0 memory allocations in RX path") Signed-off-by: Eric Dumazet <edumazet@google.com> --- drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index cec59bc264c9ac197048fd7c98bcd5cf25de0efd..0f6d2f3b7d54f51de359d4ccde21f4585e6b7852 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h@@ -102,7 +102,8 @@ /* Use the maximum between 16384 and a single page */ #define MLX4_EN_ALLOC_SIZE PAGE_ALIGN(16384) -#define MLX4_EN_ALLOC_PREFER_ORDER PAGE_ALLOC_COSTLY_ORDER +#define MLX4_EN_ALLOC_PREFER_ORDER min_t(int, get_order(32768), \ + PAGE_ALLOC_COSTLY_ORDER) /* Receive fragment sizes; we use at most 3 fragments (for 9600 byte MTU * and 4K allocations) */
Reviewed-by: Tariq Toukan <redacted> Thanks Eric!