Big servers have bloated bind table, making very hard to succeed ephemeral port allocations, without special containers/namespace tricks.
This patch series extends the strategy added in commit 07f4c90062f8 ("tcp/dccp: try to not exhaust ip_local_port_range in connect()"). Since ports used by connect() are much likely to be shared among them, we give a hint to both bind() and connect() to keep the crowds separated if possible. Of course, if on a specific host an application needs to allocate ~30000 ports using bind(), it will still be able to do so. Same for ~30000 connect() to a unique 2-tuple (dst addr, dst port) New implemetation is also more friendly to softirqs and reschedules. Eric Dumazet (2): tcp/dccp: better use of ephemeral ports in connect() tcp/dccp: better use of ephemeral ports in bind() net/ipv4/inet_connection_sock.c | 231 +++++++++++++++++++--------------------- net/ipv4/inet_hashtables.c | 170 ++++++++++++++--------------- 2 files changed, 195 insertions(+), 206 deletions(-) -- 2.7.0.rc3.207.g0ac5344