Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261603AbTEUIiV (ORCPT ); Wed, 21 May 2003 04:38:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261702AbTEUIiV (ORCPT ); Wed, 21 May 2003 04:38:21 -0400 Received: from tag.witbe.net ([81.88.96.48]:51212 "EHLO tag.witbe.net") by vger.kernel.org with ESMTP id S261603AbTEUIiU (ORCPT ); Wed, 21 May 2003 04:38:20 -0400 From: "Paul Rolland" To: Cc: Subject: e100 latency, cpu cycle saver and e1000... Date: Wed, 21 May 2003 10:51:21 +0200 Message-ID: <00e701c31f76$26fea350$3f00a8c0@witbe> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1185 Lines: 38 Hello, A few days ago, there was a thread about e100 latency related to CPU Cycle Saver... Suggestion was to disabled it to return back to some "standard" latency. At the moment, I'm experiencing some strange behavior, not with an e100 but with an e1000 on a 2.4.20 kernel... Here are some traces, using Corey Minyard test application : [root@IP3 tmp]# ./test IP1 32000 10000 370 Average: 201us, Max: 631us, Min: 200us [root@IP3 tmp]# ./test IP2 32000 10000 370 Average: 422us, Max: 47581us, Min: 209us All three machines are using 2.4.20 and e1000 drivers, they are the same hardware. But, definitely, IP2 is exhibiting much higher max latency... Increasing the packet size up to 1200 bytes doesn't change the global behavior : IP2 is always much "latent" than IP1... The problem is that it seems there is no CPU Cycle Saver on e1000 NIC. Is there some equivalent ? Could someone give a guess on what's going on ? Regards, Paul - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/