From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [Bugme-new] [Bug 10600] New: e1000 updates rx_bytes infrequently Date: Mon, 05 May 2008 16:18:06 -0700 (PDT) Message-ID: <20080505.161806.267621711.davem@davemloft.net> References: <20080505155502.3fb16590.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, bugme-daemon@bugzilla.kernel.org, jesse.brandeburg@intel.com, john.ronciak@intel.com, liblit@acm.org To: akpm@linux-foundation.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:41135 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1763292AbYEEXSG (ORCPT ); Mon, 5 May 2008 19:18:06 -0400 In-Reply-To: <20080505155502.3fb16590.akpm@linux-foundation.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Andrew Morton Date: Mon, 5 May 2008 15:55:02 -0700 > I've noticed that when I'm downloading stuff at home, gkrellm will display > eth0 as consuming 0 kbytes/sec, then 400 kbytes/sec, then 0, then 400 ad > nauseum. I always assumed that gkrellm was busted. Perhaps wrongly... It's a tradeoff between excess DMA traffic updating the statistics, and having them updated more frequently. Actually, the thing that matters is when ->get_stats() is called. So if a driver can trigger a statistics DMA update at ->get_stats() time, that's probably what it should do. But this could get expensive and make the "do DMA less often" optimization less useful.