[PATCH net-next 0/3] net: tcp: support probing OOM

[menglong8.dong@gmail.com]

From: Menglong Dong <imagedong@tencent.com>

In this series, we make some small changes to make the tcp retransmission
become zero-window probes if the receiver drops the skb because of memory
pressure.

In the 1st patch, we reply a zero-window ACK if the skb is dropped
because out of memory, instead of dropping the skb silently.

In the 2nd patch, we allow a zero-window ACK to update the window.

In the 3rd patch, we check the timeout of a probing socket with
'(u32)icsk->icsk_timeout', instead of 'tcp_jiffies32'. This is more like
a bugfix.

After these changes, the tcp can probe the OOM of the receiver forever.

Menglong Dong (3):
  net: tcp: send zero-window ACK when no memory
  net: tcp: allow zero-window ACK update the window
  net: tcp: check timeout by icsk->icsk_timeout in
    tcp_retransmit_timer()

 include/net/inet_connection_sock.h |  3 ++-
 net/ipv4/tcp_input.c               |  6 +++---
 net/ipv4/tcp_output.c              | 14 +++++++++++---
 net/ipv4/tcp_timer.c               |  6 +++++-
 4 files changed, 21 insertions(+), 8 deletions(-)

-- 
2.40.1