From 7ae92ae588c9f78006c106bb3398d50274c5d7de Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 18 Nov 2015 06:30:55 -0800 Subject: [PATCH] mlx5: add busy polling support It is now easy to add busy polling support to a NAPI driver, with very little impact on normal input path. This patch serves as a reference implementation. Note: A followup patch will add proper napi_complete_done() in mlx5, so that LINUX_MIB_BUSYPOLLRXPACKETS snmp counter is properly handled. Tested: Normal TCP_RR results without busy polling : lpk51:~# echo 0 >/proc/sys/net/core/busy_read lpk52:~# echo 0 >/proc/sys/net/core/busy_read lpk51:~# ./netperf -H 192.168.4.52 -t TCP_RR -l 10 MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.4.52 () port 0 AF_INET : first burst 0 Local /Remote Socket Size Request Resp. Elapsed Trans. Send Recv Size Size Time Rate bytes Bytes bytes bytes secs. per sec 16384 87380 1 1 10.00 53509.49 16384 87380 Now enable busy polling : lpk51:~# echo 70 >/proc/sys/net/core/busy_read lpk52:~# echo 70 >/proc/sys/net/core/busy_read lpk51:~# ./netperf -H 192.168.4.52 -t TCP_RR -l 10 MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.4.52 () port 0 AF_INET : first burst 0 Local /Remote Socket Size Request Resp. Elapsed Trans. Send Recv Size Size Time Rate bytes Bytes bytes bytes secs. per sec 16384 87380 1 1 10.00 97530.92 16384 87380 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 6 ++++++ drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 2 ++ 2 files changed, 8 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 1e52db32c73d..ffb1f9c1b973 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -982,6 +982,7 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix, mlx5e_build_channeltc_to_txq_map(priv, ix); netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64); + napi_hash_add(&c->napi); err = mlx5e_open_tx_cqs(c, cparam); if (err) @@ -1020,6 +1021,7 @@ err_close_tx_cqs: err_napi_del: netif_napi_del(&c->napi); + napi_hash_del(&c->napi); kfree(c); return err; @@ -1033,6 +1035,10 @@ static void mlx5e_close_channel(struct mlx5e_channel *c) mlx5e_close_cq(&c->rq.cq); mlx5e_close_tx_cqs(c); netif_napi_del(&c->napi); + + napi_hash_del(&c->napi); + synchronize_rcu(); + kfree(c); } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index cf0098596e85..54800c61a563 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -33,6 +33,7 @@ #include #include #include +#include #include "en.h" static inline int mlx5e_alloc_rx_wqe(struct mlx5e_rq *rq, @@ -242,6 +243,7 @@ bool mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget) wqe = mlx5_wq_ll_get_wqe(&rq->wq, wqe_counter); skb = rq->skb[wqe_counter]; prefetch(skb->data); + skb_mark_napi_id(skb, cq->napi); rq->skb[wqe_counter] = NULL; dma_unmap_single(rq->pdev, -- 2.20.1