summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c15
-rw-r--r--drivers/net/ethernet/mellanox/mlx4/en_rx.c4
-rw-r--r--include/linux/netdevice.h17
-rw-r--r--include/net/busy_poll.h5
-rw-r--r--net/core/dev.c110
5 files changed, 113 insertions, 38 deletions
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index ed42c1009685..3fd36b421d51 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -3248,13 +3248,14 @@ static int bnx2x_poll(struct napi_struct *napi, int budget)
rmb();
if (!(bnx2x_has_rx_work(fp) || bnx2x_has_tx_work(fp))) {
- napi_complete(napi);
- /* Re-enable interrupts */
- DP(NETIF_MSG_RX_STATUS,
- "Update index to %d\n", fp->fp_hc_idx);
- bnx2x_ack_sb(bp, fp->igu_sb_id, USTORM_ID,
- le16_to_cpu(fp->fp_hc_idx),
- IGU_INT_ENABLE, 1);
+ if (napi_complete_done(napi, rx_work_done)) {
+ /* Re-enable interrupts */
+ DP(NETIF_MSG_RX_STATUS,
+ "Update index to %d\n", fp->fp_hc_idx);
+ bnx2x_ack_sb(bp, fp->igu_sb_id, USTORM_ID,
+ le16_to_cpu(fp->fp_hc_idx),
+ IGU_INT_ENABLE, 1);
+ }
} else {
rx_work_done = budget;
}
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 2cc91002064f..22f08f9ef464 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -1137,8 +1137,8 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
done = 0;
}
/* Done for now */
- napi_complete_done(napi, done);
- mlx4_en_arm_cq(priv, cq);
+ if (napi_complete_done(napi, done))
+ mlx4_en_arm_cq(priv, cq);
return done;
}
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 86bacf6a64f0..bcddf951ccee 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -334,6 +334,16 @@ enum {
NAPI_STATE_NPSVC, /* Netpoll - don't dequeue from poll_list */
NAPI_STATE_HASHED, /* In NAPI hash (busy polling possible) */
NAPI_STATE_NO_BUSY_POLL,/* Do not add in napi_hash, no busy polling */
+ NAPI_STATE_IN_BUSY_POLL,/* sk_busy_loop() owns this NAPI */
+};
+
+enum {
+ NAPIF_STATE_SCHED = (1UL << NAPI_STATE_SCHED),
+ NAPIF_STATE_DISABLE = (1UL << NAPI_STATE_DISABLE),
+ NAPIF_STATE_NPSVC = (1UL << NAPI_STATE_NPSVC),
+ NAPIF_STATE_HASHED = (1UL << NAPI_STATE_HASHED),
+ NAPIF_STATE_NO_BUSY_POLL = (1UL << NAPI_STATE_NO_BUSY_POLL),
+ NAPIF_STATE_IN_BUSY_POLL = (1UL << NAPI_STATE_IN_BUSY_POLL),
};
enum gro_result {
@@ -453,16 +463,17 @@ static inline bool napi_reschedule(struct napi_struct *napi)
return false;
}
-void __napi_complete(struct napi_struct *n);
-void napi_complete_done(struct napi_struct *n, int work_done);
+bool __napi_complete(struct napi_struct *n);
+bool napi_complete_done(struct napi_struct *n, int work_done);
/**
* napi_complete - NAPI processing complete
* @n: NAPI context
*
* Mark NAPI processing as complete.
* Consider using napi_complete_done() instead.
+ * Return false if device should avoid rearming interrupts.
*/
-static inline void napi_complete(struct napi_struct *n)
+static inline bool napi_complete(struct napi_struct *n)
{
return napi_complete_done(n, 0);
}
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 2fbeb1313c0f..965e52b9b5a3 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -58,10 +58,9 @@ static inline unsigned long busy_loop_end_time(void)
return busy_loop_us_clock() + ACCESS_ONCE(sysctl_net_busy_poll);
}
-static inline bool sk_can_busy_loop(struct sock *sk)
+static inline bool sk_can_busy_loop(const struct sock *sk)
{
- return sk->sk_ll_usec && sk->sk_napi_id &&
- !need_resched() && !signal_pending(current);
+ return sk->sk_ll_usec && sk->sk_napi_id && !signal_pending(current);
}
diff --git a/net/core/dev.c b/net/core/dev.c
index 6deba68ad9e4..edba9efeb2e9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4898,26 +4898,36 @@ void __napi_schedule_irqoff(struct napi_struct *n)
}
EXPORT_SYMBOL(__napi_schedule_irqoff);
-void __napi_complete(struct napi_struct *n)
+bool __napi_complete(struct napi_struct *n)
{
BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
+ /* Some drivers call us directly, instead of calling
+ * napi_complete_done().
+ */
+ if (unlikely(test_bit(NAPI_STATE_IN_BUSY_POLL, &n->state)))
+ return false;
+
list_del_init(&n->poll_list);
smp_mb__before_atomic();
clear_bit(NAPI_STATE_SCHED, &n->state);
+ return true;
}
EXPORT_SYMBOL(__napi_complete);
-void napi_complete_done(struct napi_struct *n, int work_done)
+bool napi_complete_done(struct napi_struct *n, int work_done)
{
unsigned long flags;
/*
- * don't let napi dequeue from the cpu poll list
- * just in case its running on a different cpu
+ * 1) Don't let napi dequeue from the cpu poll list
+ * just in case its running on a different cpu.
+ * 2) If we are busy polling, do nothing here, we have
+ * the guarantee we will be called later.
*/
- if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
- return;
+ if (unlikely(n->state & (NAPIF_STATE_NPSVC |
+ NAPIF_STATE_IN_BUSY_POLL)))
+ return false;
if (n->gro_list) {
unsigned long timeout = 0;
@@ -4939,6 +4949,7 @@ void napi_complete_done(struct napi_struct *n, int work_done)
__napi_complete(n);
local_irq_restore(flags);
}
+ return true;
}
EXPORT_SYMBOL(napi_complete_done);
@@ -4956,13 +4967,41 @@ static struct napi_struct *napi_by_id(unsigned int napi_id)
}
#if defined(CONFIG_NET_RX_BUSY_POLL)
+
#define BUSY_POLL_BUDGET 8
+
+static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
+{
+ int rc;
+
+ clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
+
+ local_bh_disable();
+
+ /* All we really want here is to re-enable device interrupts.
+ * Ideally, a new ndo_busy_poll_stop() could avoid another round.
+ */
+ rc = napi->poll(napi, BUSY_POLL_BUDGET);
+ netpoll_poll_unlock(have_poll_lock);
+ if (rc == BUSY_POLL_BUDGET)
+ __napi_schedule(napi);
+ local_bh_enable();
+ if (local_softirq_pending())
+ do_softirq();
+}
+
bool sk_busy_loop(struct sock *sk, int nonblock)
{
unsigned long end_time = !nonblock ? sk_busy_loop_end_time(sk) : 0;
+ int (*napi_poll)(struct napi_struct *napi, int budget);
int (*busy_poll)(struct napi_struct *dev);
+ void *have_poll_lock = NULL;
struct napi_struct *napi;
- int rc = false;
+ int rc;
+
+restart:
+ rc = false;
+ napi_poll = NULL;
rcu_read_lock();
@@ -4973,24 +5012,33 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
/* Note: ndo_busy_poll method is optional in linux-4.5 */
busy_poll = napi->dev->netdev_ops->ndo_busy_poll;
- do {
+ preempt_disable();
+ for (;;) {
rc = 0;
local_bh_disable();
if (busy_poll) {
rc = busy_poll(napi);
- } else if (napi_schedule_prep(napi)) {
- void *have = netpoll_poll_lock(napi);
-
- if (test_bit(NAPI_STATE_SCHED, &napi->state)) {
- rc = napi->poll(napi, BUSY_POLL_BUDGET);
- trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
- if (rc == BUSY_POLL_BUDGET) {
- napi_complete_done(napi, rc);
- napi_schedule(napi);
- }
- }
- netpoll_poll_unlock(have);
+ goto count;
}
+ if (!napi_poll) {
+ unsigned long val = READ_ONCE(napi->state);
+
+ /* If multiple threads are competing for this napi,
+ * we avoid dirtying napi->state as much as we can.
+ */
+ if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
+ NAPIF_STATE_IN_BUSY_POLL))
+ goto count;
+ if (cmpxchg(&napi->state, val,
+ val | NAPIF_STATE_IN_BUSY_POLL |
+ NAPIF_STATE_SCHED) != val)
+ goto count;
+ have_poll_lock = netpoll_poll_lock(napi);
+ napi_poll = napi->poll;
+ }
+ rc = napi_poll(napi, BUSY_POLL_BUDGET);
+ trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
+count:
if (rc > 0)
__NET_ADD_STATS(sock_net(sk),
LINUX_MIB_BUSYPOLLRXPACKETS, rc);
@@ -4999,10 +5047,26 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
if (rc == LL_FLUSH_FAILED)
break; /* permanent failure */
- cpu_relax();
- } while (!nonblock && skb_queue_empty(&sk->sk_receive_queue) &&
- !need_resched() && !busy_loop_timeout(end_time));
+ if (nonblock || !skb_queue_empty(&sk->sk_receive_queue) ||
+ busy_loop_timeout(end_time))
+ break;
+ if (unlikely(need_resched())) {
+ if (napi_poll)
+ busy_poll_stop(napi, have_poll_lock);
+ preempt_enable();
+ rcu_read_unlock();
+ cond_resched();
+ rc = !skb_queue_empty(&sk->sk_receive_queue);
+ if (rc || busy_loop_timeout(end_time))
+ return rc;
+ goto restart;
+ }
+ cpu_relax_lowlatency();
+ }
+ if (napi_poll)
+ busy_poll_stop(napi, have_poll_lock);
+ preempt_enable();
rc = !skb_queue_empty(&sk->sk_receive_queue);
out:
rcu_read_unlock();
generated by cgit v1.2.3 (git 2.39.0) at 2025-12-16 11:04:14 +0300