tcp: adopt try_cmpxchg() in tcp_release_cb()

try_cmpxchg() is slighly more efficient (at least on x86),
and smp_load_acquire(&sk->sk_tsq_flags) could avoid a KCSAN report.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221110174829.3403442-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2022-11-10 17:48:29 +00:00 committed by Jakub Kicinski
parent 3e35f26d33
commit fac30731b9

View File

@ -1077,15 +1077,15 @@ static void tcp_tasklet_func(struct tasklet_struct *t)
*/
void tcp_release_cb(struct sock *sk)
{
unsigned long flags, nflags;
unsigned long flags = smp_load_acquire(&sk->sk_tsq_flags);
unsigned long nflags;
/* perform an atomic operation only if at least one flag is set */
do {
flags = sk->sk_tsq_flags;
if (!(flags & TCP_DEFERRED_ALL))
return;
nflags = flags & ~TCP_DEFERRED_ALL;
} while (cmpxchg(&sk->sk_tsq_flags, flags, nflags) != flags);
} while (!try_cmpxchg(&sk->sk_tsq_flags, &flags, nflags));
if (flags & TCPF_TSQ_DEFERRED) {
tcp_tsq_write(sk);