[net-next PATCH 4/5] net: Commonize busy polling code to focus on napi_id instead of socket

Alexander Duyck
2017-03-16T18:33:12Z

From: Sridhar Samudrala <sridhar.samudrala@intel.com>

Move the core functionality in sk_busy_loop() to napi_busy_loop() and
make it independent of sk.

This enables re-using this function in epoll busy loop implementation.

Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
include/net/busy_poll.h | 9 +++++++++
net/core/dev.c | 16 ++++++++--------
net/core/sock.c | 18 ++++++++++++++++++
3 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 67991635953e..24bc10d56b49 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -71,6 +71,9 @@ static inline bool busy_loop_timeout(unsigned long end_time)

bool sk_busy_loop(struct sock *sk, int nonblock);

+bool napi_busy_loop(unsigned int napi_id, unsigned long end_time, int nonblock,
+ bool (*loop_end)(void *), void *loop_end_arg);
+
/* used in the NIC receive handler to mark the skb */
static inline void skb_mark_napi_id(struct sk_buff *skb,
struct napi_struct *napi)
@@ -110,6 +113,12 @@ static inline bool sk_busy_loop(struct sock *sk, int nonblock)
return false;
}

+static inline bool napi_busy_loop(unsigned int napi_id, unsigned long end_time,
+ int nonblock, bool (*loop_end)(void *),
+ void *loop_end_arg)
+{
+ return false;
+}
#endif /* CONFIG_NET_RX_BUSY_POLL */

/* used in the protocol hanlder to propagate the napi_id to the socket */
diff --git a/net/core/dev.c b/net/core/dev.c
index 7869ae3837ca..4e55765c6998 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5060,9 +5060,9 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
do_softirq();
}

-bool sk_busy_loop(struct sock *sk, int nonblock)
+bool napi_busy_loop(unsigned int napi_id, unsigned long end_time, int nonblock,
+ bool (*loop_end)(void *), void *loop_end_arg)
{
- 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;
@@ -5074,7 +5074,7 @@ bool sk_busy_loop(struct sock *sk, int nonblock)

rcu_read_lock();

- napi = napi_by_id(sk->sk_napi_id);
+ napi = napi_by_id(napi_id);
if (!napi)
goto out;

@@ -5102,11 +5102,11 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
count:
if (rc > 0)
- __NET_ADD_STATS(sock_net(sk),
+ __NET_ADD_STATS(dev_net(napi->dev),
LINUX_MIB_BUSYPOLLRXPACKETS, rc);
local_bh_enable();

- if (nonblock || !skb_queue_empty(&sk->sk_receive_queue) ||
+ if (nonblock || loop_end(loop_end_arg) ||
busy_loop_timeout(end_time))
break;

@@ -5116,7 +5116,7 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
preempt_enable();
rcu_read_unlock();
cond_resched();
- rc = !skb_queue_empty(&sk->sk_receive_queue);
+ rc = loop_end(loop_end_arg);
if (rc || busy_loop_timeout(end_time))
return rc;
goto restart;
@@ -5126,12 +5126,12 @@ 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);
+ rc = loop_end(loop_end_arg);
out:
rcu_read_unlock();
return rc;
}
-EXPORT_SYMBOL(sk_busy_loop);
+EXPORT_SYMBOL(napi_busy_loop);

#endif /* CONFIG_NET_RX_BUSY_POLL */

diff --git a/net/core/sock.c b/net/core/sock.c
index 74288b2d4b3d..f606d89f044a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3205,3 +3205,21 @@ static int __init proto_init(void)
subsys_initcall(proto_init);

#endif /* PROC_FS */
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+static bool sk_napi_busy_loop_end(void *p)
+{
+ struct sock *sk = p;
+
+ return !skb_queue_empty(&sk->sk_receive_queue);
+}
+
+bool sk_busy_loop(struct sock *sk, int nonblock)
+{
+ unsigned long end_time = !nonblock ? sk_busy_loop_end_time(sk) : 0;
+
+ return napi_busy_loop(sk->sk_napi_id, end_time, nonblock,
+ sk_napi_busy_loop_end, sk);
+}
+EXPORT_SYMBOL(sk_busy_loop);
+#endif /* CONFIG_NET_RX_BUSY_POLL */