From d825da2ede50160e567e666ff43c89a403bf0193 Mon Sep 17 00:00:00 2001 From: Rick Jones Date: Mon, 10 Dec 2012 11:33:00 +0000 Subject: [PATCH] doc: Tighten-up and clarify description of tcp_fin_timeout The description for tcp_fin_timeout should be tigher and more clear. In addition to being tighter, we should make the spelling of the state name consistent with what utilities report, remove the now dated reference to 2.2 and put the default in the consistent place. Signed-off-by: Rick Jones Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 1b830cac4618..dd52d516cb89 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -224,15 +224,14 @@ tcp_fack - BOOLEAN The value is not used, if tcp_sack is not enabled. tcp_fin_timeout - INTEGER - Time to hold socket in state FIN-WAIT-2, if it was closed - by our side. Peer can be broken and never close its side, - or even died unexpectedly. Default value is 60sec. - Usual value used in 2.2 was 180 seconds, you may restore - it, but remember that if your machine is even underloaded WEB server, - you risk to overflow memory with kilotons of dead sockets, - FIN-WAIT-2 sockets are less dangerous than FIN-WAIT-1, - because they eat maximum 1.5K of memory, but they tend - to live longer. Cf. tcp_max_orphans. + The length of time an orphaned (no longer referenced by any + application) connection will remain in the FIN_WAIT_2 state + before it is aborted at the local end. While a perfectly + valid "receive only" state for an un-orphaned connection, an + orphaned connection in FIN_WAIT_2 state could otherwise wait + forever for the remote to close its end of the connection. + Cf. tcp_max_orphans + Default: 60 seconds tcp_frto - INTEGER Enables Forward RTO-Recovery (F-RTO) defined in RFC4138.