Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [RFC PATCH 15/30] net: Prepare [un]lock_sock_fast() for handling softirq mask | Date | Thu, 11 Oct 2018 01:12:02 +0200 |
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This pair of function is implemented on top of spin_lock_bh() that is going to handle a softirq mask in order to apply finegrained vector disablement. The lock function is going to return the previous vectors enabled mask prior to the last call to local_bh_disable(), following a similar model to that of local_irq_save/restore. Subsequent calls to local_bh_disable() and friends can then stack up:
bh = local_bh_disable(vec_mask); lock_sock_fast(&bh2) { *bh2 = spin_lock_bh(...) } ... unlock_sock_fast(bh2) { spin_unlock_bh(bh2, ...); } local_bh_enable(bh);
To prepare for that, make lock_sock_fast() able to return a saved vector enabled mask and pass it back to unlock_sock_fast(). We'll plug it to spin_lock_bh() in a subsequent patch.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David S. Miller <davem@davemloft.net> Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> --- include/net/sock.h | 5 +++-- net/core/datagram.c | 5 +++-- net/core/sock.c | 2 +- net/ipv4/tcp.c | 10 ++++++---- net/ipv4/udp.c | 11 +++++++---- 5 files changed, 20 insertions(+), 13 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h index 433f45f..7bba619 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1500,7 +1500,7 @@ void release_sock(struct sock *sk); SINGLE_DEPTH_NESTING) #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) -bool lock_sock_fast(struct sock *sk); +bool lock_sock_fast(struct sock *sk, unsigned int *bh); /** * unlock_sock_fast - complement of lock_sock_fast * @sk: socket @@ -1509,7 +1509,8 @@ bool lock_sock_fast(struct sock *sk); * fast unlock socket for user context. * If slow mode is on, we call regular release_sock() */ -static inline void unlock_sock_fast(struct sock *sk, bool slow) +static inline void unlock_sock_fast(struct sock *sk, bool slow, + unsigned int bh) { if (slow) release_sock(sk); diff --git a/net/core/datagram.c b/net/core/datagram.c index 9aac0d6..0cdee87 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -334,17 +334,18 @@ EXPORT_SYMBOL(skb_free_datagram); void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len) { bool slow; + unsigned int bh; if (!skb_unref(skb)) { sk_peek_offset_bwd(sk, len); return; } - slow = lock_sock_fast(sk); + slow = lock_sock_fast(sk, &bh); sk_peek_offset_bwd(sk, len); skb_orphan(skb); sk_mem_reclaim_partial(sk); - unlock_sock_fast(sk, slow); + unlock_sock_fast(sk, slow, bh); /* skb is now orphaned, can be freed outside of locked section */ __kfree_skb(skb); diff --git a/net/core/sock.c b/net/core/sock.c index 3730eb8..b886b86 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2874,7 +2874,7 @@ EXPORT_SYMBOL(release_sock); * * sk_lock.slock unlocked, owned = 1, BH enabled */ -bool lock_sock_fast(struct sock *sk) +bool lock_sock_fast(struct sock *sk, unsigned int *bh) { might_sleep(); spin_lock_bh(&sk->sk_lock.slock); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index dfd9bae..31b391a 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -605,6 +605,7 @@ EXPORT_SYMBOL(tcp_poll); int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) { struct tcp_sock *tp = tcp_sk(sk); + unsigned int bh; int answ; bool slow; @@ -613,9 +614,9 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) if (sk->sk_state == TCP_LISTEN) return -EINVAL; - slow = lock_sock_fast(sk); + slow = lock_sock_fast(sk, &bh); answ = tcp_inq(sk); - unlock_sock_fast(sk, slow); + unlock_sock_fast(sk, slow, bh); break; case SIOCATMARK: answ = tp->urg_data && tp->urg_seq == tp->copied_seq; @@ -3101,6 +3102,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) { const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ const struct inet_connection_sock *icsk = inet_csk(sk); + unsigned int bh; u32 now; u64 rate64; bool slow; @@ -3134,7 +3136,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) return; } - slow = lock_sock_fast(sk); + slow = lock_sock_fast(sk, &bh); info->tcpi_ca_state = icsk->icsk_ca_state; info->tcpi_retransmits = icsk->icsk_retransmits; @@ -3208,7 +3210,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) info->tcpi_bytes_retrans = tp->bytes_retrans; info->tcpi_dsack_dups = tp->dsack_dups; info->tcpi_reord_seen = tp->reord_seen; - unlock_sock_fast(sk, slow); + unlock_sock_fast(sk, slow, bh); } EXPORT_SYMBOL_GPL(tcp_get_info); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 7d69dd6..8148896 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1452,11 +1452,13 @@ EXPORT_SYMBOL_GPL(udp_init_sock); void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) { + unsigned int bh; + if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { - bool slow = lock_sock_fast(sk); + bool slow = lock_sock_fast(sk, &bh); sk_peek_offset_bwd(sk, len); - unlock_sock_fast(sk, slow); + unlock_sock_fast(sk, slow, bh); } if (!skb_unref(skb)) @@ -2378,10 +2380,11 @@ int udp_rcv(struct sk_buff *skb) void udp_destroy_sock(struct sock *sk) { + unsigned int bh; struct udp_sock *up = udp_sk(sk); - bool slow = lock_sock_fast(sk); + bool slow = lock_sock_fast(sk, &bh); udp_flush_pending_frames(sk); - unlock_sock_fast(sk, slow); + unlock_sock_fast(sk, slow, bh); if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) { void (*encap_destroy)(struct sock *sk); encap_destroy = READ_ONCE(up->encap_destroy); -- 2.7.4
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