mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 18:39:59 +00:00
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>
This commit is contained in:
parent
39f17b44aa
commit
46afd0fb01
2 changed files with 6 additions and 13 deletions
|
@ -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",
|
||||
|
|
|
@ -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
|
||||
|
||||
|
|
Loading…
Reference in a new issue