net: increase sk_[max_]ack_backlog
sk_ack_backlog & sk_max_ack_backlog were 16bit fields, meaning
listen() backlog was limited to 65535.
It is time to increase the width to allow much bigger backlog,
if admins change /proc/sys/net/core/somaxconn &
/proc/sys/net/ipv4/tcp_max_syn_backlog default values.
Tested:
echo 5000000 >/proc/sys/net/core/somaxconn
echo 5000000 >/proc/sys/net/ipv4/tcp_max_syn_backlog
Ran a SYNFLOOD test against a listener using listen(fd, 5000000)
myhost~# grep request_sock_TCP /proc/slabinfo
request_sock_TCP 4185642 4411940 304 13 1 : tunables 54 27 8 : slabdata 339380 339380 0
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed