From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesse Brandeburg Subject: Re: [PATCH net] e1000e: Change wthresh to 1 to avoid possible Tx stalls. Date: Tue, 9 Oct 2012 10:36:29 -0700 Message-ID: <20121009103629.0000569a@unknown> References: <20120606174355.823e9aa7.shimoda.hiroaki@gmail.com> <1339030752.2075.1.camel@jtkirshe-mobl> <1339043085.26966.77.camel@edumazet-glaptop> <1339044752.2075.14.camel@jtkirshe-mobl> <1349762863.21172.3848.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Frank Reppin , , Jeff Kirsher , jesse.brandeburg@intel.com, e1000-devel@lists.sourceforge.net To: Eric Dumazet Return-path: Received: from mga09.intel.com ([134.134.136.24]:2933 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754998Ab2JIRgp (ORCPT ); Tue, 9 Oct 2012 13:36:45 -0400 In-Reply-To: <1349762863.21172.3848.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: > > > Jesse did not share any performance numbers with me, I am sure he can > > > give some background tomorrow when he is back online. > > > > > > I am working on an alternative patch now and should have something to > > > share tomorrow. > > Please allow me to ask if there's any progess here? > > > > I've tried 3.5.4 a couple of days ago on a SuperMicro X8SIE-LN4 (82574L) > > and could still observe severe latency (up to 3000ms) spikes. > > > > Applying Hiroakis suggested patch did fix this for me as well. > > [please note as well that I didn't had this issue in any 3.4.x kernel > > before - so +1 for fixing the regression] I'm not sure what went wrong internally here that this hasn't been fixed, and I'm personally embarrassed. I am working on it until I have a patch/solution. currently am trying to reproduce the issue, am in some weird how to use BQL limbo, the lack of documentation on user usage of BQL is slowing me down. Hints or clues (I'm trying to follow the repro steps mentioned in some related threads) are appreciated.