From mboxrd@z Thu Jan 1 00:00:00 1970 From: raj@tardy.usa.hp.com (Rick Jones) Subject: [PATCH net-next] doc: Tighten-up and clarify description of tcp_fin_timeout Date: Mon, 10 Dec 2012 13:33:00 -0800 (PST) Message-ID: <20121210213300.9D6BB29003EA@tardy> To: , Return-path: Received: from g4t0015.houston.hp.com ([15.201.24.18]:14925 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353Ab2LJVdG (ORCPT ); Mon, 10 Dec 2012 16:33:06 -0500 Sender: netdev-owner@vger.kernel.org List-ID: From: Rick Jones 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 diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 1b830ca..f486c86 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.