From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: Socket buffer sizes with autotuning Date: Tue, 06 May 2008 21:28:29 -0700 (PDT) Message-ID: <20080506.212829.213490532.davem@davemloft.net> References: <20080425.000547.152086801.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: hkchu@google.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:41688 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753042AbYEGE2e (ORCPT ); Wed, 7 May 2008 00:28:34 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: "Jerry Chu" Date: Tue, 6 May 2008 20:57:46 -0700 > It may be getting a copy (e.g., when GSO is on?) hence losing all > its connection to the original tp and any chance to have the pkt > properly accounted for as host_infligh by TCP. The skb may also be > cloned more than once (e.g., due to tcpdump)... It only gets a copy if the SKB is already cloned and that clone is alive somewhere (f.e. stuck in the device, a rare occurance by the time we retransmit). It is a clone %99.999999 of the time.