From dca145ffaa8d39ea1904491ac81b92b7049372c0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 27 Oct 2014 21:45:24 -0700 Subject: tcp: allow for bigger reordering level While testing upcoming Yaogong patch (converting out of order queue into an RB tree), I hit the max reordering level of linux TCP stack. Reordering level was limited to 127 for no good reason, and some network setups [1] can easily reach this limit and get limited throughput. Allow a new max limit of 300, and add a sysctl to allow admins to even allow bigger (or lower) values if needed. [1] Aggregation of links, per packet load balancing, fabrics not doing deep packet inspections, alternative TCP congestion modules... Signed-off-by: Eric Dumazet Cc: Yaogong Wang Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a12b455928e5..9a18cdd633f3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -81,6 +81,7 @@ int sysctl_tcp_window_scaling __read_mostly = 1; int sysctl_tcp_sack __read_mostly = 1; int sysctl_tcp_fack __read_mostly = 1; int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH; +int sysctl_tcp_max_reordering __read_mostly = 300; EXPORT_SYMBOL(sysctl_tcp_reordering); int sysctl_tcp_dsack __read_mostly = 1; int sysctl_tcp_app_win __read_mostly = 31; @@ -833,7 +834,7 @@ static void tcp_update_reordering(struct sock *sk, const int metric, if (metric > tp->reordering) { int mib_idx; - tp->reordering = min(TCP_MAX_REORDERING, metric); + tp->reordering = min(sysctl_tcp_max_reordering, metric); /* This exciting event is worth to be remembered. 8) */ if (ts) -- cgit