From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Chan" Subject: Re: [Bugme-new] [Bug 10600] New: e1000 updates rx_bytes infrequently Date: Mon, 05 May 2008 18:55:49 -0700 Message-ID: <1210038949.7941.189.camel@dell> References: <20080505155502.3fb16590.akpm@linux-foundation.org> <20080505.161806.267621711.davem@davemloft.net> <481F9E64.6070606@acm.org> <1210036624.7941.183.camel@dell> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "Ben Liblit" , "David Miller" , akpm@linux-foundation.org, netdev , bugme-daemon@bugzilla.kernel.org, jesse.brandeburg@intel.com, john.ronciak@intel.com To: "Krzysztof Oledzki" Return-path: Received: from mms2.broadcom.com ([216.31.210.18]:4434 "EHLO mms2.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751989AbYEFAvY (ORCPT ); Mon, 5 May 2008 20:51:24 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2008-05-06 at 02:43 +0200, Krzysztof Oledzki wrote: > Hm... strange - I tested it on 2.6.23.17 with: > 03:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5708 > Gigabit Ethernet (rev 12) > > Setting both: > # ethtool -C eth0 stats-block-usecs 50 > and: > # ethtool -C eth0 stats-block-usecs 5000000 > gives exactly the same situation - statistics update frequency is > still ~1s. > > # ethtool -c eth1 |grep stats-block-usecs > stats-block-usecs: 999936 Unfortunately, 5708 has a bug in the statistics DMA engine that was reported here on netdev about 1 year ago. To work around it, we have to disable the statistics block DMA and rely on the driver's timer function which runs at a fixed 1 second interval. So only 0 and 999936 are allowed values on the 5708. Newer chips or the older 5706 do not have this problem.