From e8e7f018f1951b0359647ca0c1ff1be4f896b99f Mon Sep 17 00:00:00 2001 From: Ido Shamay Date: Tue, 3 Feb 2015 17:57:20 +0200 Subject: [PATCH] net/mlx4_en: Adjust RX frag strides to frag sizes This patch improves memory utilization and therefore the packets rate for special MTU's. Instead of setting the frag_stride to the maximal hard coded frag_size, use the actual frag_size that is set according to the MTU, when setting the stride of the last frag. So, for example, for MTU 1600, where the frag_size of the 2nd frag is 86, the frag_size is set to 128 instead of 4096. See below: Before: frag:0 - size:1536 prefix:0 stride:1536 frag:1 - size:86 prefix:1536 stride:4096 frag 0 allocator: - size:32768 frags:21 frag 1 allocator: - size:32768 frags:8 After: frag:0 - size:1536 prefix:0 stride:1536 frag:1 - size:86 prefix:1536 stride:128 frag 0 allocator: - size:32768 frags:21 frag 1 allocator: - size:32768 frags:256 Signed-off-by: Ido Shamay Signed-off-by: Amir Vadai Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 30a2203a7cd1..698d60de1255 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -1063,8 +1063,9 @@ void mlx4_en_calc_rx_buf(struct net_device *dev) (eff_mtu > buf_size + frag_sizes[i]) ? frag_sizes[i] : eff_mtu - buf_size; priv->frag_info[i].frag_prefix_size = buf_size; - priv->frag_info[i].frag_stride = ALIGN(frag_sizes[i], - SMP_CACHE_BYTES); + priv->frag_info[i].frag_stride = + ALIGN(priv->frag_info[i].frag_size, + SMP_CACHE_BYTES); buf_size += priv->frag_info[i].frag_size; i++; } -- 2.30.2