This is a note to let you know that I've just added the patch titled
IB/mlx5: Use cache line size to select CQE stride
to the 4.4-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:
ib-mlx5-use-cache-line-size-to-select-cqe-stride.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 16b0e0695a73b68d8ca40288c8f9614ef208917b Mon Sep 17 00:00:00 2001
From: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Date: Thu, 27 Oct 2016 16:36:41 +0300
Subject: IB/mlx5: Use cache line size to select CQE stride
From: Daniel Jurgens <danielj@xxxxxxxxxxxx>
commit 16b0e0695a73b68d8ca40288c8f9614ef208917b upstream.
When creating kernel CQs use 128B CQE stride if the
cache line size is 128B, 64B otherwise. This prevents
multiple CQEs from residing in a 128B cache line,
which can cause retries when there are concurrent
read and writes in one cache line.
Tested with IPoIB on PPC64, saw ~5% throughput
improvement.
Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters')
Signed-off-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/hw/mlx5/cq.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/infiniband/hw/mlx5/cq.c
+++ b/drivers/infiniband/hw/mlx5/cq.c
@@ -787,8 +787,7 @@ struct ib_cq *mlx5_ib_create_cq(struct i
if (err)
goto err_create;
} else {
- /* for now choose 64 bytes till we have a proper interface */
- cqe_size = 64;
+ cqe_size = cache_line_size() == 128 ? 128 : 64;
err = create_cq_kernel(dev, cq, entries, cqe_size, &cqb,
&index, &inlen);
if (err)
Patches currently in stable-queue which might be from danielj@xxxxxxxxxxxx are
queue-4.4/ib-mlx5-use-cache-line-size-to-select-cqe-stride.patch
queue-4.4/ib-mlx4-check-gid_index-return-value.patch
queue-4.4/ib-mlx4-fix-create-cq-error-flow.patch
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