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Merge branch 'tcp-avoid-indirect-call-in-__sk_stream_memory_free' 

Eric Dumazet says:

====================
tcp: avoid indirect call in __sk_stream_memory_free()

Small improvement for CONFIG_RETPOLINE=y, when dealing with TCP sockets.
====================

Link: https://lore.kernel.org/r/20201113150809.3443527-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2020-11-14 16:09:59 -08:00
parent ae8cb93286 1c5f2ced13
commit 405ac7fd39
3 changed files with 21 additions and 14 deletions
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8
include/net/sock.h
View File

@ -60,7 +60,7 @@
#include <linux/rculist_nulls.h>
#include <linux/poll.h>
#include <linux/sockptr.h>
#include <linux/indirect_call_wrapper.h>
#include <linux/atomic.h>
#include <linux/refcount.h>
#include <net/dst.h>
@ -1264,13 +1264,17 @@ static inline void sk_refcnt_debug_release(const struct sock *sk)
#define sk_refcnt_debug_release(sk) do { } while (0)
#endif /* SOCK_REFCNT_DEBUG */
INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
{
if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
return false;
return sk->sk_prot->stream_memory_free ?
sk->sk_prot->stream_memory_free(sk, wake) : true;
INDIRECT_CALL_1(sk->sk_prot->stream_memory_free,
tcp_stream_memory_free,
sk, wake) : true;
}
static inline bool sk_stream_memory_free(const struct sock *sk)

13
include/net/tcp.h
View File

@ -1965,18 +1965,7 @@ static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp)
return tp->notsent_lowat ?: net->ipv4.sysctl_tcp_notsent_lowat;
}
/* @wake is one when sk_stream_write_space() calls us.
* This sends EPOLLOUT only if notsent_bytes is half the limit.
* This mimics the strategy used in sock_def_write_space().
*/
static inline bool tcp_stream_memory_free(const struct sock *sk, int wake)
{
const struct tcp_sock *tp = tcp_sk(sk);
u32 notsent_bytes = READ_ONCE(tp->write_seq) -
READ_ONCE(tp->snd_nxt);
return (notsent_bytes << wake) < tcp_notsent_lowat(tp);
}
bool tcp_stream_memory_free(const struct sock *sk, int wake);
#ifdef CONFIG_PROC_FS
int tcp4_proc_init(void);

14
net/ipv4/tcp_ipv4.c
View File

@ -2740,6 +2740,20 @@ void tcp4_proc_exit(void)
}
#endif /* CONFIG_PROC_FS */
/* @wake is one when sk_stream_write_space() calls us.
* This sends EPOLLOUT only if notsent_bytes is half the limit.
* This mimics the strategy used in sock_def_write_space().
*/
bool tcp_stream_memory_free(const struct sock *sk, int wake)
{
const struct tcp_sock *tp = tcp_sk(sk);
u32 notsent_bytes = READ_ONCE(tp->write_seq) -
READ_ONCE(tp->snd_nxt);
return (notsent_bytes << wake) < tcp_notsent_lowat(tp);
}
EXPORT_SYMBOL(tcp_stream_memory_free);
struct proto tcp_prot = {
.name = "TCP",
.owner = THIS_MODULE,