diff options
| author |   Eric Dumazet <edumazet@google.com> | 2016-05-02 21:49:25 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2016-05-04 12:44:36 -0400 |
| commit | d4011239f46ac6e407af61e3f74d1e3874fc9394 (patch) | |
| tree | 5091043fd26ab8871104ba087894d9842a399d10 /net/ipv4/tcp.c | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff) | |
| download | linux-dev-d4011239f46ac6e407af61e3f74d1e3874fc9394.tar.xz linux-dev-d4011239f46ac6e407af61e3f74d1e3874fc9394.zip | |
tcp: guarantee forward progress in tcp_sendmsg()
Under high rx pressure, it is possible tcp_sendmsg() never has a
chance to allocate an skb and loop forever as sk_flush_backlog()
would always return true.
Fix this by calling sk_flush_backlog() only if one skb had been
allocated and filled before last backlog check.
Fixes: d41a69f1d390 ("tcp: make tcp_sendmsg() aware of socket backlog")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index b945c2b046c5..5c7ed147449c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1084,6 +1084,7 @@ int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) struct sockcm_cookie sockc; int flags, err, copied = 0; int mss_now = 0, size_goal, copied_syn = 0; + bool process_backlog = false; bool sg; long timeo; @@ -1167,9 +1168,10 @@ new_segment: if (!sk_stream_memory_free(sk)) goto wait_for_sndbuf; - if (sk_flush_backlog(sk)) + if (process_backlog && sk_flush_backlog(sk)) { + process_backlog = false; goto restart; - + } skb = sk_stream_alloc_skb(sk, select_size(sk, sg), sk->sk_allocation, @@ -1177,6 +1179,7 @@ new_segment: if (!skb) goto wait_for_memory; + process_backlog = true; /* * Check whether we can use HW checksum. */ |