While looking at UDP receive performance, I saw sk_wake_async()
was no longer inlined.
This matters at least on AMD Zen1-4 platforms (see SRSO)
This might be because rcu_read_lock() and rcu_read_unlock()
are no longer nops in recent kernels ?
Add sk_wake_async_rcu() variant, which must be called from
contexts already holding rcu lock.
As SOCK_FASYNC is deprecated in modern days, use unlikely()
to give a hint to the compiler.
sk_wake_async_rcu() is properly inlined from
__udp_enqueue_schedule_skb() and sock_def_readable().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240328144032.1864988-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
EPOLLRDNORM |
EPOLLRDBAND);
- sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
EPOLLRDNORM |
EPOLLRDBAND);
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
rcu_read_unlock();
}
}
}
+static inline void sk_wake_async_rcu(const struct sock *sk, int how, int band)
+{
+ if (unlikely(sock_flag(sk, SOCK_FASYNC)))
+ sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
+}
+
/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
* need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
* Note: for send buffers, TCP works better if we can build two skbs at
if (skwq_has_sleeper(wq))
wake_up_interruptible(&wq->wait);
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
rcu_read_unlock();
wq = rcu_dereference(sk->sk_wq);
if (skwq_has_sleeper(wq))
wake_up_interruptible_poll(&wq->wait, EPOLLERR);
- sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
+ sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
rcu_read_unlock();
}
if (skwq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
EPOLLRDNORM | EPOLLRDBAND);
- sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
rcu_read_unlock();
}
EPOLLWRNORM | EPOLLWRBAND);
/* Should agree with poll, otherwise some programs break */
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
rcu_read_unlock();
EPOLLWRNORM | EPOLLWRBAND);
/* Should agree with poll, otherwise some programs break */
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
}
wake_up_interruptible(&wq->wait);
/* Should agree with poll, otherwise some programs break */
if (sock_writeable(sk))
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
rcu_read_unlock();
}
INDIRECT_CALL_1(sk->sk_data_ready,
sock_def_readable, sk);
else
- sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
}
busylock_release(busy);
return 0;
wq = rcu_dereference(sk->sk_wq);
if (skwq_has_sleeper(wq))
wake_up_interruptible_all(&wq->wait);
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
rcu_read_unlock();
}
if (skwq_has_sleeper(wq))
wake_up_interruptible(&wq->wait);
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
rcu_read_unlock();
}
if (skwq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
EPOLLRDNORM | EPOLLRDBAND);
- sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
rcu_read_unlock();
}
if (skwq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
EPOLLRDNORM | EPOLLRDBAND);
- sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
(sk->sk_state == SMC_CLOSED))
- sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
+ sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_HUP);
rcu_read_unlock();
}
if (skwq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait,
EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND);
- sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
rcu_read_unlock();
}