From mboxrd@z Thu Jan 1 00:00:00 1970 From: David L Stevens Subject: Re: [PATCHv8 net-next 2/4] sunvnet: make transmit path zero-copy in the kernel Date: Mon, 29 Sep 2014 16:44:08 -0400 Message-ID: <5429C498.1000705@oracle.com> References: <5429B8E2.40204@oracle.com> <20140929.162950.1960056644564225055.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, sowmini.varadhan@oracle.com, raghuram.kothakota@oracle.com To: David Miller Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:36554 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753768AbaI2Unj (ORCPT ); Mon, 29 Sep 2014 16:43:39 -0400 In-Reply-To: <20140929.162950.1960056644564225055.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 09/29/2014 04:29 PM, David Miller wrote: > > It doesn't work to liberate SKBs in the TX ring purely from the > ->ndo_start_xmit() method. > > All SKBs given to a device must be liberated in a finite, short, > amount of time. I did consider putting a garbage-collector via timer on them, since we got such a boost from not ACKing every packet. I guess the question is "how short?" For example, I could leave the "normal" path like this and just start/mod a timer to do it after 1 sec if we haven't done it through start_xmit. Do you think that's sufficiently short? +-DLS