Patch "net/mlx5e: Added BW check for DIM decision mechanism" has been added to the 4.11-stable tree

This is a note to let you know that I've just added the patch titled

net/mlx5e: Added BW check for DIM decision mechanism

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-mlx5e-added-bw-check-for-dim-decision-mechanism.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Tal Gilboa <[email protected]>
Date: Mon, 15 May 2017 14:13:16 +0300
Subject: net/mlx5e: Added BW check for DIM decision mechanism

From: Tal Gilboa <[email protected]>

[ Upstream commit c3164d2fc48fd4fa0477ab658b644559c3fe9073 ]

DIM (Dynamically-tuned Interrupt Moderation) is a mechanism designed for changing the channel interrupt moderation values in order to reduce CPU overhead for all traffic types.
Until now only interrupt and packet rate were sampled.
We found a scenario on which we get a false indication since a change in DIM caused more aggregation and reduced packet rate while increasing BW.

We now regard a change as succesfull iff:
current_BW > (prev_BW + threshold) or
current_BW ~= prev_BW and current_PR > (prev_PR + threshold) or current_BW ~= prev_BW and current_PR ~= prev_PR and
current_IR < (prev_IR - threshold)
Where BW = Bandwidth, PR = Packet rate and IR = Interrupt rate

Improvements (ConnectX-4Lx 25GbE, single RX queue, LRO off)

    --------------------------------------------------
    packet size | before[Mb/s] | after[Mb/s] | gain  |
    2B          | 343.4        | 359.4       |  4.5% |
    16B         | 2739.7       | 2814.8      |  2.7% |
    64B         | 9739         | 10185.3     |  4.5% |

---
 drivers/net/ethernet/mellanox/mlx5/core/en.h       |    2 +
 drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c |   41 +++++++++++----------
 2 files changed, 24 insertions(+), 19 deletions(-)

@@ -313,12 +313,14 @@ struct mlx5e_dma_info {
 
 struct mlx5e_rx_am_stats {
 	int ppms; /* packets per msec */
+	int bpms; /* bytes per msec */
 	int epms; /* events per msec */
 };
 
 struct mlx5e_rx_am_sample {
 	ktime_t		time;
 	unsigned int	pkt_ctr;
+	unsigned int    byte_ctr;
 	u16		event_ctr;
 };
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/net-mlx5e-added-bw-check-for-dim-decision-mechanism.patch queue-4.11/net-mlx5e-fix-wrong-indications-in-dim-due-to-counter-wraparound.patch