From: Alexander Duyck <alexander.h.du...@intel.com>
>From what I can tell there is only a couple spots where we are actually
checking the return value of sk_busy_loop. As there are only a few
consumers of that data, and the data being checked for can be replaced
with a check for !skb_queue_empty() we might as well just pull the code
out of sk_busy_loop and place it in the spots that actually need it.
Signed-off-by: Alexander Duyck <alexander.h.du...@intel.com>
---
include/net/busy_poll.h | 5 ++---
net/core/datagram.c | 8 ++++++--
net/core/dev.c | 26 ++++++++++++--------------
net/sctp/socket.c | 9 ++++++---
4 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index b82d6ba70a14..c55760f4820f 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -74,7 +74,7 @@ static inline bool busy_loop_timeout(unsigned long end_time)
return time_after(now, end_time);
}
-bool sk_busy_loop(struct sock *sk, int nonblock);
+void sk_busy_loop(struct sock *sk, int nonblock);
#else /* CONFIG_NET_RX_BUSY_POLL */
static inline unsigned long net_busy_loop_on(void)
@@ -97,9 +97,8 @@ static inline bool busy_loop_timeout(unsigned long end_time)
return true;
}
-static inline bool sk_busy_loop(struct sock *sk, int nonblock)
+static inline void sk_busy_loop(struct sock *sk, int nonblock)
{
- return false;
}
#endif /* CONFIG_NET_RX_BUSY_POLL */
diff --git a/net/core/datagram.c b/net/core/datagram.c
index ea633342ab0d..4608aa245410 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -256,8 +256,12 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
unsigned int flags,
}
spin_unlock_irqrestore(&queue->lock, cpu_flags);
- } while (sk_can_busy_loop(sk) &&
- sk_busy_loop(sk, flags & MSG_DONTWAIT));
+
+ if (!sk_can_busy_loop(sk))
+ break;
+
+ sk_busy_loop(sk, flags & MSG_DONTWAIT);
+ } while (!skb_queue_empty(&sk->sk_receive_queue));
error = -EAGAIN;
diff --git a/net/core/dev.c b/net/core/dev.c
index ab337bf5bbf4..6b0458b5afe0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5060,21 +5060,21 @@ static void busy_poll_stop(struct napi_struct *napi,
void *have_poll_lock)
do_softirq();
}
-bool sk_busy_loop(struct sock *sk, int nonblock)
+void 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);
void *have_poll_lock = NULL;
struct napi_struct *napi;
unsigned int napi_id;
- int rc;
+ int work;
restart:
napi_id = READ_ONCE(sk->sk_napi_id);
if (napi_id < MIN_NAPI_ID)
- return 0;
+ return;
- rc = false;
+ work = 0;
napi_poll = NULL;
rcu_read_lock();
@@ -5085,7 +5085,7 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
preempt_disable();
for (;;) {
- rc = 0;
+ work = 0;
local_bh_disable();
if (!napi_poll) {
unsigned long val = READ_ONCE(napi->state);
@@ -5103,12 +5103,12 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
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);
+ work = napi_poll(napi, BUSY_POLL_BUDGET);
+ trace_napi_poll(napi, work, BUSY_POLL_BUDGET);
count:
- if (rc > 0)
+ if (work > 0)
__NET_ADD_STATS(sock_net(sk),
- LINUX_MIB_BUSYPOLLRXPACKETS, rc);
+ LINUX_MIB_BUSYPOLLRXPACKETS, work);
local_bh_enable();
if (nonblock || !skb_queue_empty(&sk->sk_receive_queue) ||
@@ -5121,9 +5121,9 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
preempt_enable();
rcu_read_unlock();
cond_resched();
- rc = !skb_queue_empty(&sk->sk_receive_queue);
- if (rc || busy_loop_timeout(end_time))
- return rc;
+ if (!skb_queue_empty(&sk->sk_receive_queue) ||
+ busy_loop_timeout(end_time))
+ return;
goto restart;
}
cpu_relax();
@@ -5131,10 +5131,8 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
if (napi_poll)
busy_poll_stop(napi, have_poll_lock);
preempt_enable();
- rc = !skb_queue_empty(&sk->sk_receive_queue);
out:
rcu_read_unlock();
- return rc;
}
EXPORT_SYMBOL(sk_busy_loop);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 72cc3ecf6516..ccc08fc39722 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7518,9 +7518,12 @@ struct sk_buff *sctp_skb_recv_datagram(struct sock *sk,
int flags,
if (sk->sk_shutdown & RCV_SHUTDOWN)
break;
- if (sk_can_busy_loop(sk) &&
- sk_busy_loop(sk, noblock))
- continue;
+ if (sk_can_busy_loop(sk)) {
+ sk_busy_loop(sk, noblock);
+
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ continue;
+ }
/* User doesn't want to wait. */
error = -EAGAIN;
