mlx4: reduce OOM risk on arches with large pages

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>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index d8ca6d1794ef60d7f57a3cb3724de6fa26cedf3c..4941b692e9479bc7800e92f9bfb13baf3ff7d0d4 100644 (file)
--- 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) */