diff options
| author | Yevgeny Petrilin <yevgenyp@mellanox.co.il> | 2011-03-22 22:37:36 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-03-23 12:24:16 -0700 |
| commit | 46afd0fb01d62ee217f142ab9c26054304ab7454 (patch) | |
| tree | cce928161b2b291410f07a227dd944eac24f8b4a | |
| parent | 39f17b44aaaa6bc47ded0bbb17fc617ec6cf08bb (diff) | |
mlx4_en: optimize adaptive moderation algorithm for better latency
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/mlx4/en_netdev.c | 18 | ||||
| -rw-r--r-- | drivers/net/mlx4/mlx4_en.h | 1 |
2 files changed, 6 insertions, 13 deletions
diff --git a/drivers/net/mlx4/en_netdev.c b/drivers/net/mlx4/en_netdev.c index 56627c26d918..b1180dd5e173 100644 --- a/drivers/net/mlx4/en_netdev.c +++ b/drivers/net/mlx4/en_netdev.c @@ -417,7 +417,6 @@ static void mlx4_en_auto_moderation(struct mlx4_en_priv *priv) unsigned long avg_pkt_size; unsigned long rx_packets; unsigned long rx_bytes; - unsigned long rx_byte_diff; unsigned long tx_packets; unsigned long tx_pkt_diff; unsigned long rx_pkt_diff; @@ -441,25 +440,20 @@ static void mlx4_en_auto_moderation(struct mlx4_en_priv *priv) rx_pkt_diff = ((unsigned long) (rx_packets - priv->last_moder_packets)); packets = max(tx_pkt_diff, rx_pkt_diff); - rx_byte_diff = rx_bytes - priv->last_moder_bytes; - rx_byte_diff = rx_byte_diff ? rx_byte_diff : 1; rate = packets * HZ / period; avg_pkt_size = packets ? ((unsigned long) (rx_bytes - priv->last_moder_bytes)) / packets : 0; /* Apply auto-moderation only when packet rate exceeds a rate that * it matters */ - if (rate > MLX4_EN_RX_RATE_THRESH) { + if (rate > MLX4_EN_RX_RATE_THRESH && avg_pkt_size > MLX4_EN_AVG_PKT_SMALL) { /* If tx and rx packet rates are not balanced, assume that * traffic is mainly BW bound and apply maximum moderation. * Otherwise, moderate according to packet rate */ - if (2 * tx_pkt_diff > 3 * rx_pkt_diff && - rx_pkt_diff / rx_byte_diff < - MLX4_EN_SMALL_PKT_SIZE) - moder_time = priv->rx_usecs_low; - else if (2 * rx_pkt_diff > 3 * tx_pkt_diff) + if (2 * tx_pkt_diff > 3 * rx_pkt_diff || + 2 * rx_pkt_diff > 3 * tx_pkt_diff) { moder_time = priv->rx_usecs_high; - else { + } else { if (rate < priv->pkt_rate_low) moder_time = priv->rx_usecs_low; else if (rate > priv->pkt_rate_high) @@ -471,9 +465,7 @@ static void mlx4_en_auto_moderation(struct mlx4_en_priv *priv) priv->rx_usecs_low; } } else { - /* When packet rate is low, use default moderation rather than - * 0 to prevent interrupt storms if traffic suddenly increases */ - moder_time = priv->rx_usecs; + moder_time = priv->rx_usecs_low; } en_dbg(INTR, priv, "tx rate:%lu rx_rate:%lu\n", diff --git a/drivers/net/mlx4/mlx4_en.h b/drivers/net/mlx4/mlx4_en.h index dfed6a07c2d7..5387c4e9f295 100644 --- a/drivers/net/mlx4/mlx4_en.h +++ b/drivers/net/mlx4/mlx4_en.h @@ -124,6 +124,7 @@ enum { #define MLX4_EN_RX_SIZE_THRESH 1024 #define MLX4_EN_RX_RATE_THRESH (1000000 / MLX4_EN_RX_COAL_TIME_HIGH) #define MLX4_EN_SAMPLE_INTERVAL 0 +#define MLX4_EN_AVG_PKT_SMALL 256 #define MLX4_EN_AUTO_CONF 0xffff |