From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislav Meduna Subject: e1000e 82574L transmit latency? Date: Tue, 28 May 2013 14:45:43 +0200 Message-ID: <51A4A6F7.5090909@meduna.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: e1000-devel@lists.sourceforge.net To: "linux-rt-users@vger.kernel.org" Return-path: Received: from www.meduna.org ([92.240.244.38]:46350 "EHLO meduna.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759083Ab3E1Mpw (ORCPT ); Tue, 28 May 2013 08:45:52 -0400 Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi, anyone has experience / knows of bugs (not the ASPM one) causing high (at least 70 ms) latency on Intel 82574L using the e1000e driver? We have an instance of a connected device needing to be serviced each 100 ms reporting a timeout while our internal measurements show that the packets were given to the kernel max 30 ms apart. These are raw packets, there is no other traffic on that interface, no kernel messages, no errors in the /sys/class/net/eth1/statistics/* and it happened after 5 days of uptime :/ I am using kernel 3.4 with RT PREEMPT - I note that the driver version there is 1.9.5 while in 3.9 it is 2.2.14. Anyone knows if the network drivers are back-portable without much hassle that far or whether this is a complicated task? e1000-devel: please Cc: me when replying, I am not subscribed to the list. Thanks -- Stano