This is a note to let you know that I've just added the patch titled
net/mlx5e: Fix fixpoint divide exception in mlx5e_am_stats_compare
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: net-mlx5e-fix-fixpoint-divide-exception-in-mlx5e_am_stats_compare.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Sun Jan 28 17:35:08 CET 2018
From: Talat Batheesh talatb@mellanox.com Date: Sun, 21 Jan 2018 05:30:42 +0200 Subject: net/mlx5e: Fix fixpoint divide exception in mlx5e_am_stats_compare
From: Talat Batheesh talatb@mellanox.com
[ Upstream commit e58edaa4863583b54409444f11b4f80dff0af1cd ]
Helmut reported a bug about division by zero while running traffic and doing physical cable pull test.
When the cable unplugged the ppms become zero, so when dividing the current ppms by the previous ppms in the next dim iteration there is division by zero.
This patch prevent this division for both ppms and epms.
Fixes: c3164d2fc48f ("net/mlx5e: Added BW check for DIM decision mechanism") Reported-by: Helmut Grauer helmut.grauer@de.ibm.com Signed-off-by: Talat Batheesh talatb@mellanox.com Signed-off-by: Saeed Mahameed saeedm@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c @@ -197,9 +197,15 @@ static int mlx5e_am_stats_compare(struct return (curr->bpms > prev->bpms) ? MLX5E_AM_STATS_BETTER : MLX5E_AM_STATS_WORSE;
+ if (!prev->ppms) + return curr->ppms ? MLX5E_AM_STATS_BETTER : + MLX5E_AM_STATS_SAME; + if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms)) return (curr->ppms > prev->ppms) ? MLX5E_AM_STATS_BETTER : MLX5E_AM_STATS_WORSE; + if (!prev->epms) + return MLX5E_AM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms)) return (curr->epms < prev->epms) ? MLX5E_AM_STATS_BETTER :
Patches currently in stable-queue which might be from talatb@mellanox.com are
queue-4.14/net-mlx5e-fix-fixpoint-divide-exception-in-mlx5e_am_stats_compare.patch