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Message-Id: <1447768624-14962-10-git-send-email-edumazet@google.com>
Date: Tue, 17 Nov 2015 05:57:04 -0800
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>
Cc: netdev <netdev@...r.kernel.org>, Eli Cohen <eli@...lanox.com>,
Amir Vadai <amirv@...lanox.com>,
Ariel Elior <ariel.elior@...gic.com>,
Willem de Bruijn <willemb@...gle.com>,
Rida Assaf <rida@...gle.com>,
Eric Dumazet <edumazet@...gle.com>,
Eric Dumazet <eric.dumazet@...il.com>
Subject: [PATCH net-next 9/9] mlx4: remove mlx4_en_low_latency_recv()
Busy polling can now be handled in generic NAPI poll infrastructure.
This removes complexity and fast path overhead :
mlx4 used two spin_lock()/spin_unlock() pair per napi->poll() call
in mlx4_en_cq_lock_napi()/mlx4_en_cq_unlock_napi()
Tested:
Without busy polling :
lpaa23:~# echo 0 >/proc/sys/net/core/busy_read
lpaa24:~# echo 0 >/proc/sys/net/core/busy_read
lpaa23:~# ./netperf -H lpaa24 -t TCP_RR
MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to lpaa24.prod.google.com () 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 47330.78
With busy polling :
lpaa23:~# echo 70 >/proc/sys/net/core/busy_read
lpaa24:~# echo 70 >/proc/sys/net/core/busy_read
lpaa23:~# ./netperf -H lpaa24 -t TCP_RR
MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to lpaa24.prod.google.com () 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 97643.55
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
drivers/net/ethernet/mellanox/mlx4/en_ethtool.c | 17 ----
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 40 --------
drivers/net/ethernet/mellanox/mlx4/en_rx.c | 15 +--
drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 128 ------------------------
4 files changed, 2 insertions(+), 198 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index ddb5541882f5..dd84cabb2a51 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -337,11 +337,7 @@ static int mlx4_en_get_sset_count(struct net_device *dev, int sset)
case ETH_SS_STATS:
return bitmap_iterator_count(&it) +
(priv->tx_ring_num * 2) +
-#ifdef CONFIG_NET_RX_BUSY_POLL
- (priv->rx_ring_num * 5);
-#else
(priv->rx_ring_num * 2);
-#endif
case ETH_SS_TEST:
return MLX4_EN_NUM_SELF_TEST - !(priv->mdev->dev->caps.flags
& MLX4_DEV_CAP_FLAG_UC_LOOPBACK) * 2;
@@ -408,11 +404,6 @@ static void mlx4_en_get_ethtool_stats(struct net_device *dev,
for (i = 0; i < priv->rx_ring_num; i++) {
data[index++] = priv->rx_ring[i]->packets;
data[index++] = priv->rx_ring[i]->bytes;
-#ifdef CONFIG_NET_RX_BUSY_POLL
- data[index++] = priv->rx_ring[i]->yields;
- data[index++] = priv->rx_ring[i]->misses;
- data[index++] = priv->rx_ring[i]->cleaned;
-#endif
}
spin_unlock_bh(&priv->stats_lock);
@@ -486,14 +477,6 @@ static void mlx4_en_get_strings(struct net_device *dev,
"rx%d_packets", i);
sprintf(data + (index++) * ETH_GSTRING_LEN,
"rx%d_bytes", i);
-#ifdef CONFIG_NET_RX_BUSY_POLL
- sprintf(data + (index++) * ETH_GSTRING_LEN,
- "rx%d_napi_yield", i);
- sprintf(data + (index++) * ETH_GSTRING_LEN,
- "rx%d_misses", i);
- sprintf(data + (index++) * ETH_GSTRING_LEN,
- "rx%d_cleaned", i);
-#endif
}
break;
case ETH_SS_PRIV_FLAGS:
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 886e1bc86374..659209ff7af6 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -69,34 +69,6 @@ int mlx4_en_setup_tc(struct net_device *dev, u8 up)
return 0;
}
-#ifdef CONFIG_NET_RX_BUSY_POLL
-/* must be called with local_bh_disable()d */
-static int mlx4_en_low_latency_recv(struct napi_struct *napi)
-{
- struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
- struct net_device *dev = cq->dev;
- struct mlx4_en_priv *priv = netdev_priv(dev);
- struct mlx4_en_rx_ring *rx_ring = priv->rx_ring[cq->ring];
- int done;
-
- if (!priv->port_up)
- return LL_FLUSH_FAILED;
-
- if (!mlx4_en_cq_lock_poll(cq))
- return LL_FLUSH_BUSY;
-
- done = mlx4_en_process_rx_cq(dev, cq, 4);
- if (likely(done))
- rx_ring->cleaned += done;
- else
- rx_ring->misses++;
-
- mlx4_en_cq_unlock_poll(cq);
-
- return done;
-}
-#endif /* CONFIG_NET_RX_BUSY_POLL */
-
#ifdef CONFIG_RFS_ACCEL
struct mlx4_en_filter {
@@ -1561,8 +1533,6 @@ int mlx4_en_start_port(struct net_device *dev)
for (i = 0; i < priv->rx_ring_num; i++) {
cq = priv->rx_cq[i];
- mlx4_en_cq_init_lock(cq);
-
err = mlx4_en_init_affinity_hint(priv, i);
if (err) {
en_err(priv, "Failed preparing IRQ affinity hint\n");
@@ -1859,13 +1829,6 @@ void mlx4_en_stop_port(struct net_device *dev, int detach)
for (i = 0; i < priv->rx_ring_num; i++) {
struct mlx4_en_cq *cq = priv->rx_cq[i];
- local_bh_disable();
- while (!mlx4_en_cq_lock_napi(cq)) {
- pr_info("CQ %d locked\n", i);
- mdelay(1);
- }
- local_bh_enable();
-
napi_synchronize(&cq->napi);
mlx4_en_deactivate_rx_ring(priv, priv->rx_ring[i]);
mlx4_en_deactivate_cq(priv, cq);
@@ -2504,9 +2467,6 @@ static const struct net_device_ops mlx4_netdev_ops = {
#ifdef CONFIG_RFS_ACCEL
.ndo_rx_flow_steer = mlx4_en_filter_rfs,
#endif
-#ifdef CONFIG_NET_RX_BUSY_POLL
- .ndo_busy_poll = mlx4_en_low_latency_recv,
-#endif
.ndo_get_phys_port_id = mlx4_en_get_phys_port_id,
#ifdef CONFIG_MLX4_EN_VXLAN
.ndo_add_vxlan_port = mlx4_en_add_vxlan_port,
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index e7a5000aa12c..1feead34093b 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -873,10 +873,8 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
* - TCP/IP (v4)
* - without IP options
* - not an IP fragment
- * - no LLS polling in progress
*/
- if (!mlx4_en_cq_busy_polling(cq) &&
- (dev->features & NETIF_F_GRO)) {
+ if (dev->features & NETIF_F_GRO) {
struct sk_buff *gro_skb = napi_get_frags(&cq->napi);
if (!gro_skb)
goto next;
@@ -992,11 +990,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
skb_mark_napi_id(skb, &cq->napi);
- if (!mlx4_en_cq_busy_polling(cq))
- napi_gro_receive(&cq->napi, skb);
- else
- netif_receive_skb(skb);
-
+ napi_gro_receive(&cq->napi, skb);
next:
for (nr = 0; nr < priv->num_frags; nr++)
mlx4_en_free_frag(priv, frags, nr);
@@ -1038,13 +1032,8 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
struct mlx4_en_priv *priv = netdev_priv(dev);
int done;
- if (!mlx4_en_cq_lock_napi(cq))
- return budget;
-
done = mlx4_en_process_rx_cq(dev, cq, budget);
- mlx4_en_cq_unlock_napi(cq);
-
/* If we used up all the quota - we're probably not done yet... */
if (done == budget) {
const struct cpumask *aff;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 965c8f016ac4..35de7d2e6b34 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -320,11 +320,6 @@ struct mlx4_en_rx_ring {
void *rx_info;
unsigned long bytes;
unsigned long packets;
-#ifdef CONFIG_NET_RX_BUSY_POLL
- unsigned long yields;
- unsigned long misses;
- unsigned long cleaned;
-#endif
unsigned long csum_ok;
unsigned long csum_none;
unsigned long csum_complete;
@@ -347,18 +342,6 @@ struct mlx4_en_cq {
struct mlx4_cqe *buf;
#define MLX4_EN_OPCODE_ERROR 0x1e
-#ifdef CONFIG_NET_RX_BUSY_POLL
- unsigned int state;
-#define MLX4_EN_CQ_STATE_IDLE 0
-#define MLX4_EN_CQ_STATE_NAPI 1 /* NAPI owns this CQ */
-#define MLX4_EN_CQ_STATE_POLL 2 /* poll owns this CQ */
-#define MLX4_CQ_LOCKED (MLX4_EN_CQ_STATE_NAPI | MLX4_EN_CQ_STATE_POLL)
-#define MLX4_EN_CQ_STATE_NAPI_YIELD 4 /* NAPI yielded this CQ */
-#define MLX4_EN_CQ_STATE_POLL_YIELD 8 /* poll yielded this CQ */
-#define CQ_YIELD (MLX4_EN_CQ_STATE_NAPI_YIELD | MLX4_EN_CQ_STATE_POLL_YIELD)
-#define CQ_USER_PEND (MLX4_EN_CQ_STATE_POLL | MLX4_EN_CQ_STATE_POLL_YIELD)
- spinlock_t poll_lock; /* protects from LLS/napi conflicts */
-#endif /* CONFIG_NET_RX_BUSY_POLL */
struct irq_desc *irq_desc;
};
@@ -622,117 +605,6 @@ static inline struct mlx4_cqe *mlx4_en_get_cqe(void *buf, int idx, int cqe_sz)
return buf + idx * cqe_sz;
}
-#ifdef CONFIG_NET_RX_BUSY_POLL
-static inline void mlx4_en_cq_init_lock(struct mlx4_en_cq *cq)
-{
- spin_lock_init(&cq->poll_lock);
- cq->state = MLX4_EN_CQ_STATE_IDLE;
-}
-
-/* called from the device poll rutine to get ownership of a cq */
-static inline bool mlx4_en_cq_lock_napi(struct mlx4_en_cq *cq)
-{
- int rc = true;
- spin_lock(&cq->poll_lock);
- if (cq->state & MLX4_CQ_LOCKED) {
- WARN_ON(cq->state & MLX4_EN_CQ_STATE_NAPI);
- cq->state |= MLX4_EN_CQ_STATE_NAPI_YIELD;
- rc = false;
- } else
- /* we don't care if someone yielded */
- cq->state = MLX4_EN_CQ_STATE_NAPI;
- spin_unlock(&cq->poll_lock);
- return rc;
-}
-
-/* returns true is someone tried to get the cq while napi had it */
-static inline bool mlx4_en_cq_unlock_napi(struct mlx4_en_cq *cq)
-{
- int rc = false;
- spin_lock(&cq->poll_lock);
- WARN_ON(cq->state & (MLX4_EN_CQ_STATE_POLL |
- MLX4_EN_CQ_STATE_NAPI_YIELD));
-
- if (cq->state & MLX4_EN_CQ_STATE_POLL_YIELD)
- rc = true;
- cq->state = MLX4_EN_CQ_STATE_IDLE;
- spin_unlock(&cq->poll_lock);
- return rc;
-}
-
-/* called from mlx4_en_low_latency_recv(), BH are disabled */
-static inline bool mlx4_en_cq_lock_poll(struct mlx4_en_cq *cq)
-{
- int rc = true;
-
- spin_lock(&cq->poll_lock);
- if ((cq->state & MLX4_CQ_LOCKED)) {
- struct net_device *dev = cq->dev;
- struct mlx4_en_priv *priv = netdev_priv(dev);
- struct mlx4_en_rx_ring *rx_ring = priv->rx_ring[cq->ring];
-
- cq->state |= MLX4_EN_CQ_STATE_POLL_YIELD;
- rc = false;
- rx_ring->yields++;
- } else
- /* preserve yield marks */
- cq->state |= MLX4_EN_CQ_STATE_POLL;
- spin_unlock(&cq->poll_lock);
- return rc;
-}
-
-/* returns true if someone tried to get the cq while it was locked */
-static inline bool mlx4_en_cq_unlock_poll(struct mlx4_en_cq *cq)
-{
- int rc = false;
-
- spin_lock(&cq->poll_lock);
- WARN_ON(cq->state & (MLX4_EN_CQ_STATE_NAPI));
-
- if (cq->state & MLX4_EN_CQ_STATE_POLL_YIELD)
- rc = true;
- cq->state = MLX4_EN_CQ_STATE_IDLE;
- spin_unlock(&cq->poll_lock);
- return rc;
-}
-
-/* true if a socket is polling, even if it did not get the lock */
-static inline bool mlx4_en_cq_busy_polling(struct mlx4_en_cq *cq)
-{
- WARN_ON(!(cq->state & MLX4_CQ_LOCKED));
- return cq->state & CQ_USER_PEND;
-}
-#else
-static inline void mlx4_en_cq_init_lock(struct mlx4_en_cq *cq)
-{
-}
-
-static inline bool mlx4_en_cq_lock_napi(struct mlx4_en_cq *cq)
-{
- return true;
-}
-
-static inline bool mlx4_en_cq_unlock_napi(struct mlx4_en_cq *cq)
-{
- return false;
-}
-
-static inline bool mlx4_en_cq_lock_poll(struct mlx4_en_cq *cq)
-{
- return false;
-}
-
-static inline bool mlx4_en_cq_unlock_poll(struct mlx4_en_cq *cq)
-{
- return false;
-}
-
-static inline bool mlx4_en_cq_busy_polling(struct mlx4_en_cq *cq)
-{
- return false;
-}
-#endif /* CONFIG_NET_RX_BUSY_POLL */
-
#define MLX4_EN_WOL_DO_MODIFY (1ULL << 63)
void mlx4_en_update_loopback_state(struct net_device *dev,
--
2.6.0.rc2.230.g3dd15c0
--
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