diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-01-18 20:17:49 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-01-21 18:09:30 +0000 |
| commit | a54d51fb2dfb846aedf3751af501e9688db447f5 (patch) | |
| tree | a7caec9bea91b6523352babace79103a93c5b514 /net | |
| parent | e3f9bed9bee261e3347131764e42aeedf1ffea61 (diff) | |
udp: fix busy polling
Generic sk_busy_loop_end() only looks at sk->sk_receive_queue
for presence of packets.
Problem is that for UDP sockets after blamed commit, some packets
could be present in another queue: udp_sk(sk)->reader_queue
In some cases, a busy poller could spin until timeout expiration,
even if some packets are available in udp_sk(sk)->reader_queue.
v3: - make sk_busy_loop_end() nicer (Willem)
v2: - add a READ_ONCE(sk->sk_family) in sk_is_inet() to avoid KCSAN splats.
- add a sk_is_inet() check in sk_is_udp() (Willem feedback)
- add a sk_is_inet() check in sk_is_tcp().
Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/sock.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 158dbdebce6a..0a7f46c37f0c 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -107,6 +107,7 @@ #include <linux/interrupt.h> #include <linux/poll.h> #include <linux/tcp.h> +#include <linux/udp.h> #include <linux/init.h> #include <linux/highmem.h> #include <linux/user_namespace.h> @@ -4144,8 +4145,14 @@ bool sk_busy_loop_end(void *p, unsigned long start_time) { struct sock *sk = p; - return !skb_queue_empty_lockless(&sk->sk_receive_queue) || - sk_busy_loop_timeout(sk, start_time); + if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) + return true; + + if (sk_is_udp(sk) && + !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue)) + return true; + + return sk_busy_loop_timeout(sk, start_time); } EXPORT_SYMBOL(sk_busy_loop_end); #endif /* CONFIG_NET_RX_BUSY_POLL */ |