Commit e048fc50 authored Jan 18, 2017 by Eric Dumazet Committed by David S. Miller Jan 20, 2017

net/mlx5e: Do not recycle pages from emergency reserve



A driver using dev_alloc_page() must not reuse a page allocated from
emergency memory reserve.

Otherwise all packets using this page will be immediately dropped,
unless for very specific sockets having SOCK_MEMALLOC bit set.

This issue might be hard to debug, because only a fraction of received
packets would be dropped.

Fixes: 4415a031 ("net/mlx5e: Implement RX mapped page cache for page recycle")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent cdb749ce

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -193,6 +193,9 @@ static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq,
		return false;
		}

		if (unlikely(page_is_pfmemalloc(dma_info->page)))
		return false;

		cache->page_cache[cache->tail] = *dma_info;
		cache->tail = tail_next;
		return true;