From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: How I can reset TCP sockets after long suspend/resume cyscle Date: Thu, 05 Jun 2008 14:50:39 -0700 Message-ID: <48485FAF.6010801@hp.com> References: <200806011515.14103.maximlevitsky@gmail.com> <20080604141533.35eb6df0@extreme> <484707D9.3040900@hp.com> <200806060031.16827.maximlevitsky@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , Adam Langley , netdev@vger.kernel.org To: Maxim Levitsky Return-path: Received: from g1t0026.austin.hp.com ([15.216.28.33]:33185 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751539AbYFEVum (ORCPT ); Thu, 5 Jun 2008 17:50:42 -0400 In-Reply-To: <200806060031.16827.maximlevitsky@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Maxim Levitsky wrote: > On Thursday, 5 June 2008 00:23:37 Rick Jones wrote: >>Would you have it done even for those endpoints on which SO_KEEPALIVE >>wasn't set? > > > Why not? Apart from just general paranoia? Nothing besides perhaps spite for having to cover the backside of an application which on the surface at least does not appear to have attempted to make itself suspend/resume friendly :) Although how TCP could tell an application with its own keepalive vs one that simply didn't bother I'm not at all sure. > This seems the right solution, if this is possible, why not to check > for stuck TCP connections on resume? The prospect is perhaps far-fetched, but the application could be in communication with another laptop, also in a long suspend, and initiating keepalive when the application did not request it could trigger a connection drop it was not otherwise expecting after the N keepalive probes were not answered (because the other end was suspended). Of course, ostensibly such a connection should already be dealing with connection drop but still... rick jones