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net/mlx5e: Optimize mlx5e_select_queue

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This commit optimizes mlx5e_select_queue for HTB and PTP cases by
short-cutting some checks, without sacrificing performance of the common
non-HTB non-PTP flow.

1. The HTB flow uses the fact that num_tcs == 1 to drop these checks
(it's not possible to attach both mqprio and htb as the root qdisc).
It's also enough to calculate `txq_ix % num_channels` only once, instead
of twice.

2. The PTP flow drops the check for HTB and the second calculation of
`txq_ix % num_channels`.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
This commit is contained in:
Maxim Mikityanskiy 2022-01-25 12:52:57 +02:00 committed by Saeed Mahameed
parent ed5f9cf06b
commit 3c87aedd48
1 changed files with 44 additions and 18 deletions
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62
drivers/net/ethernet/mellanox/mlx5/core/en/selq.c
View File

@ -164,36 +164,62 @@ u16 mlx5e_select_queue(struct net_device *dev, struct sk_buff *skb,
if (unlikely(!selq))
return 0;
if (unlikely(selq->is_ptp || selq->is_htb)) {
if (unlikely(selq->is_htb)) {
txq_ix = mlx5e_select_htb_queue(priv, skb);
if (txq_ix > 0)
return txq_ix;
}
if (unlikely(selq->is_ptp && mlx5e_use_ptpsq(skb)))
return mlx5e_select_ptpsq(dev, skb, selq);
if (likely(!selq->is_ptp && !selq->is_htb)) {
/* No special queues, netdev_pick_tx returns one of the regular ones. */
txq_ix = netdev_pick_tx(dev, skb, NULL);
if (selq->num_tcs <= 1)
return txq_ix;
up = mlx5e_get_up(priv, skb);
/* Normalize any picked txq_ix to [0, num_channels),
* So we can return a txq_ix that matches the channel and
* packet UP.
*/
return txq_ix % selq->num_channels + up * selq->num_channels;
}
if (unlikely(selq->is_htb)) {
/* num_tcs == 1, shortcut for PTP */
txq_ix = mlx5e_select_htb_queue(priv, skb);
if (txq_ix > 0)
return txq_ix;
if (unlikely(selq->is_ptp && mlx5e_use_ptpsq(skb)))
return selq->num_channels;
txq_ix = netdev_pick_tx(dev, skb, NULL);
/* Fix netdev_pick_tx() not to choose ptp_channel and HTB txqs.
* If they are selected, switch to regular queues.
* Driver to select these queues only at mlx5e_select_ptpsq()
* and mlx5e_select_htb_queue().
*/
if (unlikely(txq_ix >= selq->num_regular_queues))
txq_ix %= selq->num_regular_queues;
} else {
txq_ix = netdev_pick_tx(dev, skb, NULL);
return txq_ix % selq->num_channels;
}
/* PTP is enabled */
if (mlx5e_use_ptpsq(skb))
return mlx5e_select_ptpsq(dev, skb, selq);
txq_ix = netdev_pick_tx(dev, skb, NULL);
/* Normalize any picked txq_ix to [0, num_channels). Queues in range
* [0, num_regular_queues) will be mapped to the corresponding channel
* index, so that we can apply the packet's UP (if num_tcs > 1).
* If netdev_pick_tx() picks ptp_channel, switch to a regular queue,
* because driver should select the PTP only at mlx5e_select_ptpsq().
*/
txq_ix %= selq->num_channels;
if (selq->num_tcs <= 1)
return txq_ix;
up = mlx5e_get_up(priv, skb);
/* Normalize any picked txq_ix to [0, num_channels),
* So we can return a txq_ix that matches the channel and
* packet UP.
*/
return txq_ix % selq->num_channels + up * selq->num_channels;
return txq_ix + up * selq->num_channels;
}