linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* socket poll related cleanups v2
@ 2018-07-30  7:42 Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 1/4] net: simplify sock_poll_wait Christoph Hellwig
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-07-30  7:42 UTC (permalink / raw)
  To: netdev; +Cc: linux-kernel

A couple of cleanups I stumbled upon when studying the networking
poll code.

Changes since v1:
 - drop a dispute patch from this series (to be sent separately)

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH 1/4] net: simplify sock_poll_wait
  2018-07-30  7:42 socket poll related cleanups v2 Christoph Hellwig
@ 2018-07-30  7:42 ` Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 2/4] net: don not detour through struct sock to find the poll waitqueue Christoph Hellwig
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-07-30  7:42 UTC (permalink / raw)
  To: netdev; +Cc: linux-kernel

The wait_address argument is always directly derived from the filp
argument, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 crypto/af_alg.c        |  2 +-
 include/net/sock.h     | 11 ++++++-----
 net/atm/common.c       |  2 +-
 net/caif/caif_socket.c |  2 +-
 net/core/datagram.c    |  2 +-
 net/dccp/proto.c       |  2 +-
 net/ipv4/tcp.c         |  2 +-
 net/iucv/af_iucv.c     |  2 +-
 net/nfc/llcp_sock.c    |  2 +-
 net/rxrpc/af_rxrpc.c   |  2 +-
 net/smc/af_smc.c       |  2 +-
 net/tipc/socket.c      |  2 +-
 net/unix/af_unix.c     |  4 ++--
 13 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index c166f424871c..b053179e0bc5 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -1071,7 +1071,7 @@ __poll_t af_alg_poll(struct file *file, struct socket *sock,
 	struct af_alg_ctx *ctx = ask->private;
 	__poll_t mask;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	if (!ctx->more || ctx->used)
diff --git a/include/net/sock.h b/include/net/sock.h
index b3b75419eafe..762069bb0d8c 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1994,16 +1994,17 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq)
 /**
  * sock_poll_wait - place memory barrier behind the poll_wait call.
  * @filp:           file
- * @wait_address:   socket wait queue
  * @p:              poll_table
  *
  * See the comments in the wq_has_sleeper function.
  */
-static inline void sock_poll_wait(struct file *filp,
-		wait_queue_head_t *wait_address, poll_table *p)
+static inline void sock_poll_wait(struct file *filp, poll_table *p)
 {
-	if (!poll_does_not_wait(p) && wait_address) {
-		poll_wait(filp, wait_address, p);
+	struct socket *sock = filp->private_data;
+	wait_queue_head_t *wq = sk_sleep(sock->sk);
+
+	if (!poll_does_not_wait(p) && wq) {
+		poll_wait(filp, wq, p);
 		/* We need to be sure we are in sync with the
 		 * socket flags modification.
 		 *
diff --git a/net/atm/common.c b/net/atm/common.c
index a7a68e509628..9f8cb0d2e71e 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -653,7 +653,7 @@ __poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait)
 	struct atm_vcc *vcc;
 	__poll_t mask;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	vcc = ATM_SD(sock);
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index a6fb1b3bcad9..d18965f3291f 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -941,7 +941,7 @@ static __poll_t caif_poll(struct file *file,
 	__poll_t mask;
 	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	/* exceptional events? */
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 9938952c5c78..9aac0d63d53e 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -837,7 +837,7 @@ __poll_t datagram_poll(struct file *file, struct socket *sock,
 	struct sock *sk = sock->sk;
 	__poll_t mask;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	/* exceptional events? */
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 0d56e36a6db7..875858c8b059 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -325,7 +325,7 @@ __poll_t dccp_poll(struct file *file, struct socket *sock,
 	__poll_t mask;
 	struct sock *sk = sock->sk;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	if (sk->sk_state == DCCP_LISTEN)
 		return inet_csk_listen_poll(sk);
 
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 4491faf83f4f..0b93290c9255 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -507,7 +507,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 	const struct tcp_sock *tp = tcp_sk(sk);
 	int state;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 
 	state = inet_sk_state_load(sk);
 	if (state == TCP_LISTEN)
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 893a022f9620..e7b93cd14b52 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1494,7 +1494,7 @@ __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
 	struct sock *sk = sock->sk;
 	__poll_t mask = 0;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 
 	if (sk->sk_state == IUCV_LISTEN)
 		return iucv_accept_poll(sk);
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index ea0c0c6f1874..dd4adf8b1167 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -556,7 +556,7 @@ static __poll_t llcp_sock_poll(struct file *file, struct socket *sock,
 
 	pr_debug("%p\n", sk);
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 
 	if (sk->sk_state == LLCP_LISTEN)
 		return llcp_accept_poll(sk);
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 2b463047dd7b..ac44d8afffb1 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -741,7 +741,7 @@ static __poll_t rxrpc_poll(struct file *file, struct socket *sock,
 	struct rxrpc_sock *rx = rxrpc_sk(sk);
 	__poll_t mask;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	/* the socket is readable if there are any messages waiting on the Rx
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 05e4ffe5aabd..09df79313f60 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1351,7 +1351,7 @@ static __poll_t smc_poll(struct file *file, struct socket *sock,
 			mask |= EPOLLERR;
 	} else {
 		if (sk->sk_state != SMC_CLOSED)
-			sock_poll_wait(file, sk_sleep(sk), wait);
+			sock_poll_wait(file, wait);
 		if (sk->sk_err)
 			mask |= EPOLLERR;
 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 930852c54d7a..9a9050131724 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -716,7 +716,7 @@ static __poll_t tipc_poll(struct file *file, struct socket *sock,
 	struct tipc_sock *tsk = tipc_sk(sk);
 	__poll_t revents = 0;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		revents |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e5473c03d667..1772a0e32665 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2635,7 +2635,7 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa
 	struct sock *sk = sock->sk;
 	__poll_t mask;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	/* exceptional events? */
@@ -2672,7 +2672,7 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock,
 	unsigned int writable;
 	__poll_t mask;
 
-	sock_poll_wait(file, sk_sleep(sk), wait);
+	sock_poll_wait(file, wait);
 	mask = 0;
 
 	/* exceptional events? */
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 2/4] net: don not detour through struct sock to find the poll waitqueue
  2018-07-30  7:42 socket poll related cleanups v2 Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 1/4] net: simplify sock_poll_wait Christoph Hellwig
@ 2018-07-30  7:42 ` Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 3/4] net: remove sock_poll_busy_loop Christoph Hellwig
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-07-30  7:42 UTC (permalink / raw)
  To: netdev; +Cc: linux-kernel

For any open socket file descriptor sock->sk->sk_wq->wait will always
point to sock->wq->wait.  That means we can do the shorter dereference
and removal a NULL check and don't have to not worry about any RCU
protection.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/net/sock.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 762069bb0d8c..7927541101a8 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2001,10 +2001,9 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq)
 static inline void sock_poll_wait(struct file *filp, poll_table *p)
 {
 	struct socket *sock = filp->private_data;
-	wait_queue_head_t *wq = sk_sleep(sock->sk);
 
-	if (!poll_does_not_wait(p) && wq) {
-		poll_wait(filp, wq, p);
+	if (!poll_does_not_wait(p)) {
+		poll_wait(filp, &sock->wq->wait, p);
 		/* We need to be sure we are in sync with the
 		 * socket flags modification.
 		 *
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 3/4] net: remove sock_poll_busy_loop
  2018-07-30  7:42 socket poll related cleanups v2 Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 1/4] net: simplify sock_poll_wait Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 2/4] net: don not detour through struct sock to find the poll waitqueue Christoph Hellwig
@ 2018-07-30  7:42 ` Christoph Hellwig
  2018-07-30  7:42 ` [PATCH 4/4] net: remove sock_poll_busy_flag Christoph Hellwig
  2018-07-30 16:13 ` socket poll related cleanups v2 David Miller
  4 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-07-30  7:42 UTC (permalink / raw)
  To: netdev; +Cc: linux-kernel

There is no point in hiding this logic in a helper.  Also remove the
useless events != 0 check and only busy loop once we know we actually
have a poll method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/net/busy_poll.h | 9 ---------
 net/socket.c            | 5 ++++-
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index c5187438af38..25d762cf47f2 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -121,15 +121,6 @@ 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)
 {
diff --git a/net/socket.c b/net/socket.c
index 85633622c94d..674434127b3a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1132,9 +1132,12 @@ static __poll_t sock_poll(struct file *file, poll_table *wait)
 	struct socket *sock = file->private_data;
 	__poll_t events = poll_requested_events(wait);
 
-	sock_poll_busy_loop(sock, events);
 	if (!sock->ops->poll)
 		return 0;
+
+	/* poll once if requested by the syscall */
+	if (sk_can_busy_loop(sock->sk) && (events & POLL_BUSY_LOOP))
+		sk_busy_loop(sock->sk, 1);
 	return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock);
 }
 
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 4/4] net: remove sock_poll_busy_flag
  2018-07-30  7:42 socket poll related cleanups v2 Christoph Hellwig
                   ` (2 preceding siblings ...)
  2018-07-30  7:42 ` [PATCH 3/4] net: remove sock_poll_busy_loop Christoph Hellwig
@ 2018-07-30  7:42 ` Christoph Hellwig
  2018-07-30 16:13 ` socket poll related cleanups v2 David Miller
  4 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-07-30  7:42 UTC (permalink / raw)
  To: netdev; +Cc: linux-kernel

Fold it into the only caller to make the code simpler and easier to read.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/net/busy_poll.h |  6 ------
 net/socket.c            | 16 +++++++++++-----
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 25d762cf47f2..71c72a939bf8 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -121,12 +121,6 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock)
 #endif
 }
 
-/* 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 674434127b3a..5b7df6695f4f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1130,15 +1130,21 @@ EXPORT_SYMBOL(sock_create_lite);
 static __poll_t sock_poll(struct file *file, poll_table *wait)
 {
 	struct socket *sock = file->private_data;
-	__poll_t events = poll_requested_events(wait);
+	__poll_t events = poll_requested_events(wait), flag = 0;
 
 	if (!sock->ops->poll)
 		return 0;
 
-	/* poll once if requested by the syscall */
-	if (sk_can_busy_loop(sock->sk) && (events & POLL_BUSY_LOOP))
-		sk_busy_loop(sock->sk, 1);
-	return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock);
+	if (sk_can_busy_loop(sock->sk)) {
+		/* poll once if requested by the syscall */
+		if (events & POLL_BUSY_LOOP)
+			sk_busy_loop(sock->sk, 1);
+
+		/* if this socket can poll_ll, tell the system call */
+		flag = POLL_BUSY_LOOP;
+	}
+
+	return sock->ops->poll(file, sock, wait) | flag;
 }
 
 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: socket poll related cleanups v2
  2018-07-30  7:42 socket poll related cleanups v2 Christoph Hellwig
                   ` (3 preceding siblings ...)
  2018-07-30  7:42 ` [PATCH 4/4] net: remove sock_poll_busy_flag Christoph Hellwig
@ 2018-07-30 16:13 ` David Miller
  4 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2018-07-30 16:13 UTC (permalink / raw)
  To: hch; +Cc: netdev, linux-kernel

From: Christoph Hellwig <hch@lst.de>
Date: Mon, 30 Jul 2018 09:42:09 +0200

> A couple of cleanups I stumbled upon when studying the networking
> poll code.
> 
> Changes since v1:
>  - drop a dispute patch from this series (to be sent separately)

Series applied, thanks!

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-07-30 16:13 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-30  7:42 socket poll related cleanups v2 Christoph Hellwig
2018-07-30  7:42 ` [PATCH 1/4] net: simplify sock_poll_wait Christoph Hellwig
2018-07-30  7:42 ` [PATCH 2/4] net: don not detour through struct sock to find the poll waitqueue Christoph Hellwig
2018-07-30  7:42 ` [PATCH 3/4] net: remove sock_poll_busy_loop Christoph Hellwig
2018-07-30  7:42 ` [PATCH 4/4] net: remove sock_poll_busy_flag Christoph Hellwig
2018-07-30 16:13 ` socket poll related cleanups v2 David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).