于 2015年02月13日 20:31, Eric Dumazet 写道:

On Fri, 2015-02-13 at 16:16 +0800, Fan Du wrote:

quoted

quoted

As per RFC4821 7.3.  Selecting Probe Size, a probe timer should
be armed once probing has converged. Once this timer expired,
probing again to take advantage of any path PMTU change. The
recommended probing interval is 10 minutes per RFC1981.

Signed-off-by: Fan Du<redacted>
---
 include/net/inet_connection_sock.h |    2 ++
 include/net/netns/ipv4.h           |    1 +
 include/net/tcp.h                  |    3 +++
 net/ipv4/sysctl_net_ipv4.c         |    7 +++++++
 net/ipv4/tcp.c                     |    2 ++
 net/ipv4/tcp_ipv4.c                |    1 +
 net/ipv4/tcp_output.c              |   23 ++++++++++++++++++++++-
 7 files changed, 38 insertions(+), 1 deletions(-)

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index 3d0932e..e78e5ab 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h

@@ -126,6 +126,8 @@ struct inet_connection_sock {

 		int		  search_high_sav;
 		int		  search_low_sav;
+
+		struct timer_list probe_timer;

We certainly wont add yet another timer in tcp socket for such usage.

And a buggy one, since you forgot all the refcounting associated with
such timers.

oh, embarrassing...
Will place probe timer aside with icsk_delack_timer in struct inet_connection_sock,
and manipulate through sk_reset_timer.

Thanks for the reviewing.