Commit ee02c269 authored Jun 11, 2019 by Ido Schimmel Committed by David S. Miller Jun 12, 2019

mlxsw: spectrum: Use different seeds for ECMP and LAG hash



The same hash function and seed are used for both ECMP and LAG hash.
Therefore, when a LAG device is used as a nexthop device as part of an
ECMP group, hash polarization can occur and all the traffic will be
hashed to a single LAG slave.

Fix this by using a different seed for the LAG hash.

Fixes: fa73989f ("mlxsw: spectrum: Use a stable ECMP/LAG seed")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alex Veber <alexve@mellanox.com>
Tested-by: Alex Veber <alexve@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 648ee6ce

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -4280,13 +4280,16 @@ static void mlxsw_sp_traps_fini(struct mlxsw_sp *mlxsw_sp)
		}
		}

		#define MLXSW_SP_LAG_SEED_INIT 0xcafecafe

		static int mlxsw_sp_lag_init(struct mlxsw_sp *mlxsw_sp)
		{
		char slcr_pl[MLXSW_REG_SLCR_LEN];
		u32 seed;
		int err;

		seed = jhash(mlxsw_sp->base_mac, sizeof(mlxsw_sp->base_mac), 0);
		seed = jhash(mlxsw_sp->base_mac, sizeof(mlxsw_sp->base_mac),
		MLXSW_SP_LAG_SEED_INIT);
		mlxsw_reg_slcr_pack(slcr_pl, MLXSW_REG_SLCR_LAG_HASH_SMAC \|
		MLXSW_REG_SLCR_LAG_HASH_DMAC \|
		MLXSW_REG_SLCR_LAG_HASH_ETHERTYPE \|

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