From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ayaz Abdulla Subject: Re: [PATCH 10/12] forcedeth: tx max work Date: Fri, 19 Jan 2007 11:27:02 -0500 Message-ID: <45B0F156.4050504@nvidia.com> References: <45A3DF43.8030301@nvidia.com> <45B03271.5080802@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Manfred Spraul , Andrew Morton , netdev@vger.kernel.org Return-path: Received: from hqemgate02.nvidia.com ([216.228.112.143]:10172 "EHLO HQEMGATE02.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964932AbXASWCW (ORCPT ); Fri, 19 Jan 2007 17:02:22 -0500 To: Jeff Garzik In-Reply-To: <45B03271.5080802@pobox.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Jeff Garzik wrote: > Ayaz Abdulla wrote: > > This patch adds a limit to how much tx work can be done in each > > iteration of tx processing. > > > > Signed-Off-By: Ayaz Abdulla > > What about the "tail end" of the work, when the limit is reached? > > Remember that delaying the completion of TX's too long increases latency. > > It seems to me that this patch needs a timer or somesuch, to guarantee > that TX completions are not delayed too long in the worst case. Yes, you are right. There is a timer interrupt that fires in throughput mode every 10ms (in cpu mode it fires at approx every 130us). I can use that to clean out any uncompleted TXs. Let me know if 10ms is not too late for worst case tx completion. > > Jeff > > >