From 3608b13ccc51d06e499dfe12b27f134de1286e28 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Sat, 18 Feb 2017 10:34:18 -0800
Subject: [PATCH] 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>
---
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 d8ca6d1794ef6..4941b692e9479 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) */
--
2.30.2