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net/tcp: use deferred jump label for TCP acked data hook

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User space can flip the clean_acked_data_enabled static branch
on and off with TLS offload when CONFIG_TLS_DEVICE is enabled.
jump_label.h suggests we use the delayed version in this case.

Deferred branches now also don't take the branch mutex on
decrement, so we avoid potential locking issues.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2019-05-08 16:46:14 -07:00 committed by David S. Miller
parent 70610c922b
commit 494bc1d281
3 changed files with 13 additions and 6 deletions
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2
include/net/tcp.h
View file

@ -2198,7 +2198,7 @@ extern struct static_key_false tcp_have_smc;
void clean_acked_data_enable(struct inet_connection_sock *icsk,
void (*cad)(struct sock *sk, u32 ack_seq));
void clean_acked_data_disable(struct inet_connection_sock *icsk);
void clean_acked_data_flush(void);
#endif
#endif /* _TCP_H */

16
net/ipv4/tcp_input.c
View file

@ -77,7 +77,7 @@
#include <asm/unaligned.h>
#include <linux/errqueue.h>
#include <trace/events/tcp.h>
#include <linux/static_key.h>
#include <linux/jump_label_ratelimit.h>
#include <net/busy_poll.h>
int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
@ -113,22 +113,28 @@ int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
#define REXMIT_NEW 2 /* FRTO-style transmit of unsent/new packets */
#if IS_ENABLED(CONFIG_TLS_DEVICE)
static DEFINE_STATIC_KEY_FALSE(clean_acked_data_enabled);
static DEFINE_STATIC_KEY_DEFERRED_FALSE(clean_acked_data_enabled, HZ);
void clean_acked_data_enable(struct inet_connection_sock *icsk,
void (*cad)(struct sock *sk, u32 ack_seq))
{
icsk->icsk_clean_acked = cad;
static_branch_inc(&clean_acked_data_enabled);
static_branch_inc(&clean_acked_data_enabled.key);
}
EXPORT_SYMBOL_GPL(clean_acked_data_enable);
void clean_acked_data_disable(struct inet_connection_sock *icsk)
{
static_branch_dec(&clean_acked_data_enabled);
static_branch_slow_dec_deferred(&clean_acked_data_enabled);
icsk->icsk_clean_acked = NULL;
}
EXPORT_SYMBOL_GPL(clean_acked_data_disable);
void clean_acked_data_flush(void)
{
static_key_deferred_flush(&clean_acked_data_enabled);
}
EXPORT_SYMBOL_GPL(clean_acked_data_flush);
#endif
static void tcp_gro_dev_warn(struct sock *sk, const struct sk_buff *skb,
@ -3598,7 +3604,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
icsk->icsk_retransmits = 0;
#if IS_ENABLED(CONFIG_TLS_DEVICE)
if (static_branch_unlikely(&clean_acked_data_enabled))
if (static_branch_unlikely(&clean_acked_data_enabled.key))
if (icsk->icsk_clean_acked)
icsk->icsk_clean_acked(sk, ack);
#endif

1
net/tls/tls_device.c
View file

@ -1036,4 +1036,5 @@ void __exit tls_device_cleanup(void)
{
unregister_netdevice_notifier(&tls_dev_notifier);
flush_work(&tls_device_gc_work);
clean_acked_data_flush();
}