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-rw-r--r--include/linux/tcp.h12
-rw-r--r--include/net/sock.h51
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_ipv4.c2
-rw-r--r--net/ipv4/tcp_output.c91
-rw-r--r--net/ipv4/tcp_timer.c4
-rw-r--r--net/ipv6/tcp_ipv6.c2
7 files changed, 98 insertions, 68 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 734bab4c3bef..fc5848dad7a4 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -186,7 +186,6 @@ struct tcp_sock {
u32 tsoffset; /* timestamp offset */
struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
- unsigned long tsq_flags;
/* Data for direct copy to user */
struct {
@@ -364,7 +363,7 @@ struct tcp_sock {
u32 *saved_syn;
};
-enum tsq_flags {
+enum tsq_enum {
TSQ_THROTTLED,
TSQ_QUEUED,
TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */
@@ -375,6 +374,15 @@ enum tsq_flags {
*/
};
+enum tsq_flags {
+ TSQF_THROTTLED = (1UL << TSQ_THROTTLED),
+ TSQF_QUEUED = (1UL << TSQ_QUEUED),
+ TCPF_TSQ_DEFERRED = (1UL << TCP_TSQ_DEFERRED),
+ TCPF_WRITE_TIMER_DEFERRED = (1UL << TCP_WRITE_TIMER_DEFERRED),
+ TCPF_DELACK_TIMER_DEFERRED = (1UL << TCP_DELACK_TIMER_DEFERRED),
+ TCPF_MTU_REDUCED_DEFERRED = (1UL << TCP_MTU_REDUCED_DEFERRED),
+};
+
static inline struct tcp_sock *tcp_sk(const struct sock *sk)
{
return (struct tcp_sock *)sk;
diff --git a/include/net/sock.h b/include/net/sock.h
index 69afda6bea15..6dfe3aa22b97 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -343,6 +343,9 @@ struct sock {
#define sk_rxhash __sk_common.skc_rxhash
socket_lock_t sk_lock;
+ atomic_t sk_drops;
+ int sk_rcvlowat;
+ struct sk_buff_head sk_error_queue;
struct sk_buff_head sk_receive_queue;
/*
* The backlog queue is special, it is always used with
@@ -359,14 +362,13 @@ struct sock {
struct sk_buff *tail;
} sk_backlog;
#define sk_rmem_alloc sk_backlog.rmem_alloc
- int sk_forward_alloc;
- __u32 sk_txhash;
+ int sk_forward_alloc;
#ifdef CONFIG_NET_RX_BUSY_POLL
- unsigned int sk_napi_id;
unsigned int sk_ll_usec;
+ /* ===== mostly read cache line ===== */
+ unsigned int sk_napi_id;
#endif
- atomic_t sk_drops;
int sk_rcvbuf;
struct sk_filter __rcu *sk_filter;
@@ -379,11 +381,30 @@ struct sock {
#endif
struct dst_entry *sk_rx_dst;
struct dst_entry __rcu *sk_dst_cache;
- /* Note: 32bit hole on 64bit arches */
- atomic_t sk_wmem_alloc;
atomic_t sk_omem_alloc;
int sk_sndbuf;
+
+ /* ===== cache line for TX ===== */
+ int sk_wmem_queued;
+ atomic_t sk_wmem_alloc;
+ unsigned long sk_tsq_flags;
+ struct sk_buff *sk_send_head;
struct sk_buff_head sk_write_queue;
+ __s32 sk_peek_off;
+ int sk_write_pending;
+ long sk_sndtimeo;
+ struct timer_list sk_timer;
+ __u32 sk_priority;
+ __u32 sk_mark;
+ u32 sk_pacing_rate; /* bytes per second */
+ u32 sk_max_pacing_rate;
+ struct page_frag sk_frag;
+ netdev_features_t sk_route_caps;
+ netdev_features_t sk_route_nocaps;
+ int sk_gso_type;
+ unsigned int sk_gso_max_size;
+ gfp_t sk_allocation;
+ __u32 sk_txhash;
/*
* Because of non atomicity rules, all
@@ -414,42 +435,24 @@ struct sock {
#define SK_PROTOCOL_MAX U8_MAX
kmemcheck_bitfield_end(flags);
- int sk_wmem_queued;
- gfp_t sk_allocation;
- u32 sk_pacing_rate; /* bytes per second */
- u32 sk_max_pacing_rate;
- netdev_features_t sk_route_caps;
- netdev_features_t sk_route_nocaps;
- int sk_gso_type;
- unsigned int sk_gso_max_size;
u16 sk_gso_max_segs;
- int sk_rcvlowat;
unsigned long sk_lingertime;
- struct sk_buff_head sk_error_queue;
struct proto *sk_prot_creator;
rwlock_t sk_callback_lock;
int sk_err,
sk_err_soft;
u32 sk_ack_backlog;
u32 sk_max_ack_backlog;
- __u32 sk_priority;
- __u32 sk_mark;
kuid_t sk_uid;
struct pid *sk_peer_pid;
const struct cred *sk_peer_cred;
long sk_rcvtimeo;
- long sk_sndtimeo;
- struct timer_list sk_timer;
ktime_t sk_stamp;
u16 sk_tsflags;
u8 sk_shutdown;
u32 sk_tskey;
struct socket *sk_socket;
void *sk_user_data;
- struct page_frag sk_frag;
- struct sk_buff *sk_send_head;
- __s32 sk_peek_off;
- int sk_write_pending;
#ifdef CONFIG_SECURITY
void *sk_security;
#endif
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1149b48700a1..1ef3165114ba 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -663,9 +663,9 @@ static void tcp_push(struct sock *sk, int flags, int mss_now,
if (tcp_should_autocork(sk, skb, size_goal)) {
/* avoid atomic op if TSQ_THROTTLED bit is already set */
- if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) {
+ if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
- set_bit(TSQ_THROTTLED, &tp->tsq_flags);
+ set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
}
/* It is possible TX completion already happened
* before we set TSQ_THROTTLED.
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index b50f05905ced..30d81f533ada 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -443,7 +443,7 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
if (!sock_owned_by_user(sk)) {
tcp_v4_mtu_reduced(sk);
} else {
- if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags))
+ if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &sk->sk_tsq_flags))
sock_hold(sk);
}
goto out;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index c7adcb57654e..b45101f3d2bd 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -769,25 +769,26 @@ static void tcp_tasklet_func(unsigned long data)
list_del(&tp->tsq_node);
sk = (struct sock *)tp;
- bh_lock_sock(sk);
-
- if (!sock_owned_by_user(sk)) {
- tcp_tsq_handler(sk);
- } else {
- /* defer the work to tcp_release_cb() */
- set_bit(TCP_TSQ_DEFERRED, &tp->tsq_flags);
+ clear_bit(TSQ_QUEUED, &sk->sk_tsq_flags);
+
+ if (!sk->sk_lock.owned &&
+ test_bit(TCP_TSQ_DEFERRED, &sk->sk_tsq_flags)) {
+ bh_lock_sock(sk);
+ if (!sock_owned_by_user(sk)) {
+ clear_bit(TCP_TSQ_DEFERRED, &sk->sk_tsq_flags);
+ tcp_tsq_handler(sk);
+ }
+ bh_unlock_sock(sk);
}
- bh_unlock_sock(sk);
- clear_bit(TSQ_QUEUED, &tp->tsq_flags);
sk_free(sk);
}
}
-#define TCP_DEFERRED_ALL ((1UL << TCP_TSQ_DEFERRED) | \
- (1UL << TCP_WRITE_TIMER_DEFERRED) | \
- (1UL << TCP_DELACK_TIMER_DEFERRED) | \
- (1UL << TCP_MTU_REDUCED_DEFERRED))
+#define TCP_DEFERRED_ALL (TCPF_TSQ_DEFERRED | \
+ TCPF_WRITE_TIMER_DEFERRED | \
+ TCPF_DELACK_TIMER_DEFERRED | \
+ TCPF_MTU_REDUCED_DEFERRED)
/**
* tcp_release_cb - tcp release_sock() callback
* @sk: socket
@@ -797,18 +798,17 @@ static void tcp_tasklet_func(unsigned long data)
*/
void tcp_release_cb(struct sock *sk)
{
- struct tcp_sock *tp = tcp_sk(sk);
unsigned long flags, nflags;
/* perform an atomic operation only if at least one flag is set */
do {
- flags = tp->tsq_flags;
+ flags = sk->sk_tsq_flags;
if (!(flags & TCP_DEFERRED_ALL))
return;
nflags = flags & ~TCP_DEFERRED_ALL;
- } while (cmpxchg(&tp->tsq_flags, flags, nflags) != flags);
+ } while (cmpxchg(&sk->sk_tsq_flags, flags, nflags) != flags);
- if (flags & (1UL << TCP_TSQ_DEFERRED))
+ if (flags & TCPF_TSQ_DEFERRED)
tcp_tsq_handler(sk);
/* Here begins the tricky part :
@@ -822,15 +822,15 @@ void tcp_release_cb(struct sock *sk)
*/
sock_release_ownership(sk);
- if (flags & (1UL << TCP_WRITE_TIMER_DEFERRED)) {
+ if (flags & TCPF_WRITE_TIMER_DEFERRED) {
tcp_write_timer_handler(sk);
__sock_put(sk);
}
- if (flags & (1UL << TCP_DELACK_TIMER_DEFERRED)) {
+ if (flags & TCPF_DELACK_TIMER_DEFERRED) {
tcp_delack_timer_handler(sk);
__sock_put(sk);
}
- if (flags & (1UL << TCP_MTU_REDUCED_DEFERRED)) {
+ if (flags & TCPF_MTU_REDUCED_DEFERRED) {
inet_csk(sk)->icsk_af_ops->mtu_reduced(sk);
__sock_put(sk);
}
@@ -860,6 +860,7 @@ void tcp_wfree(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
struct tcp_sock *tp = tcp_sk(sk);
+ unsigned long flags, nval, oval;
int wmem;
/* Keep one reference on sk_wmem_alloc.
@@ -877,16 +878,25 @@ void tcp_wfree(struct sk_buff *skb)
if (wmem >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current)
goto out;
- if (test_and_clear_bit(TSQ_THROTTLED, &tp->tsq_flags) &&
- !test_and_set_bit(TSQ_QUEUED, &tp->tsq_flags)) {
- unsigned long flags;
+ for (oval = READ_ONCE(sk->sk_tsq_flags);; oval = nval) {
struct tsq_tasklet *tsq;
+ bool empty;
+
+ if (!(oval & TSQF_THROTTLED) || (oval & TSQF_QUEUED))
+ goto out;
+
+ nval = (oval & ~TSQF_THROTTLED) | TSQF_QUEUED | TCPF_TSQ_DEFERRED;
+ nval = cmpxchg(&sk->sk_tsq_flags, oval, nval);
+ if (nval != oval)
+ continue;
/* queue this socket to tasklet queue */
local_irq_save(flags);
tsq = this_cpu_ptr(&tsq_tasklet);
+ empty = list_empty(&tsq->head);
list_add(&tp->tsq_node, &tsq->head);
- tasklet_schedule(&tsq->tasklet);
+ if (empty)
+ tasklet_schedule(&tsq->tasklet);
local_irq_restore(flags);
return;
}
@@ -1922,26 +1932,26 @@ static inline void tcp_mtu_check_reprobe(struct sock *sk)
*/
static int tcp_mtu_probe(struct sock *sk)
{
- struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb, *nskb, *next;
struct net *net = sock_net(sk);
- int len;
int probe_size;
int size_needed;
- int copy;
+ int copy, len;
int mss_now;
int interval;
/* Not currently probing/verifying,
* not in recovery,
* have enough cwnd, and
- * not SACKing (the variable headers throw things off) */
- if (!icsk->icsk_mtup.enabled ||
- icsk->icsk_mtup.probe_size ||
- inet_csk(sk)->icsk_ca_state != TCP_CA_Open ||
- tp->snd_cwnd < 11 ||
- tp->rx_opt.num_sacks || tp->rx_opt.dsack)
+ * not SACKing (the variable headers throw things off)
+ */
+ if (likely(!icsk->icsk_mtup.enabled ||
+ icsk->icsk_mtup.probe_size ||
+ inet_csk(sk)->icsk_ca_state != TCP_CA_Open ||
+ tp->snd_cwnd < 11 ||
+ tp->rx_opt.num_sacks || tp->rx_opt.dsack))
return -1;
/* Use binary search for probe_size between tcp_mss_base,
@@ -2081,7 +2091,16 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
limit <<= factor;
if (atomic_read(&sk->sk_wmem_alloc) > limit) {
- set_bit(TSQ_THROTTLED, &tcp_sk(sk)->tsq_flags);
+ /* Always send the 1st or 2nd skb in write queue.
+ * No need to wait for TX completion to call us back,
+ * after softirq/tasklet schedule.
+ * This helps when TX completions are delayed too much.
+ */
+ if (skb == sk->sk_write_queue.next ||
+ skb->prev == sk->sk_write_queue.next)
+ return false;
+
+ set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
/* It is possible TX completion already happened
* before we set TSQ_THROTTLED, so we must
* test again the condition.
@@ -2222,6 +2241,8 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
break;
+ if (test_bit(TCP_TSQ_DEFERRED, &sk->sk_tsq_flags))
+ clear_bit(TCP_TSQ_DEFERRED, &sk->sk_tsq_flags);
if (tcp_small_queue_check(sk, skb, 0))
break;
@@ -3524,8 +3545,6 @@ void tcp_send_ack(struct sock *sk)
/* We do not want pure acks influencing TCP Small Queues or fq/pacing
* too much.
* SKB_TRUESIZE(max(1 .. 66, MAX_TCP_HEADER)) is unfortunately ~784
- * We also avoid tcp_wfree() overhead (cache line miss accessing
- * tp->tsq_flags) by using regular sock_wfree()
*/
skb_set_tcp_pure_ack(buff);
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 3ea1cf804748..3705075f42c3 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -310,7 +310,7 @@ static void tcp_delack_timer(unsigned long data)
inet_csk(sk)->icsk_ack.blocked = 1;
__NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
/* deleguate our work to tcp_release_cb() */
- if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
+ if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &sk->sk_tsq_flags))
sock_hold(sk);
}
bh_unlock_sock(sk);
@@ -592,7 +592,7 @@ static void tcp_write_timer(unsigned long data)
tcp_write_timer_handler(sk);
} else {
/* delegate our work to tcp_release_cb() */
- if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
+ if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &sk->sk_tsq_flags))
sock_hold(sk);
}
bh_unlock_sock(sk);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index a2185a214abc..73bc8fc68acd 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -399,7 +399,7 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
if (!sock_owned_by_user(sk))
tcp_v6_mtu_reduced(sk);
else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
- &tp->tsq_flags))
+ &sk->sk_tsq_flags))
sock_hold(sk);
goto out;
}