[PATCH 15/36] net: refactor socket_poll

Christoph Hellwig
2018-01-22T20:13:39Z

Factor out two busy poll related helpers for late reuse, and remove
a command that isn't very helpful, especially with the __poll_t
annotations in place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/net/busy_poll.h | 15 +++++++++++++++
net/socket.c | 21 ++++-----------------
2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 71c72a939bf8..c5187438af38 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -121,6 +121,21 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock)
#endif
}

+static inline void sock_poll_busy_loop(struct socket *sock, __poll_t events)
+{
+ if (sk_can_busy_loop(sock->sk) &&
+ events && (events & POLL_BUSY_LOOP)) {
+ /* once, only if requested by syscall */
+ sk_busy_loop(sock->sk, 1);
+ }
+}
+
+/* if this socket can poll_ll, tell the system call */
+static inline __poll_t sock_poll_busy_flag(struct socket *sock)
+{
+ return sk_can_busy_loop(sock->sk) ? POLL_BUSY_LOOP : 0;
+}
+
/* 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)
diff --git a/net/socket.c b/net/socket.c
index 092baa464afc..db11e48a375b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1097,24 +1097,11 @@ EXPORT_SYMBOL(sock_create_lite);
/* No kernel lock held - perfect */
static __poll_t sock_poll(struct file *file, poll_table *wait)
{
- __poll_t busy_flag = 0;
- struct socket *sock;
-
- /*
- * We can't return errors to poll, so it's either yes or no.
- */
- sock = file->private_data;
-
- if (sk_can_busy_loop(sock->sk)) {
- /* this socket can poll_ll so tell the system call */
- busy_flag = POLL_BUSY_LOOP;
-
- /* once, only if requested by syscall */
- if (wait && (wait->_key & POLL_BUSY_LOOP))
- sk_busy_loop(sock->sk, 1);
- }
+ struct socket *sock = file->private_data;
+ __poll_t events = poll_requested_events(wait);

- return busy_flag | sock->ops->poll(file, sock, wait);
+ sock_poll_busy_loop(sock, events);
+ return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock);
}

static int sock_mmap(struct file *file, struct vm_area_struct *vma)
--
2.14.2