From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 3/3] net: core: add IFLA_STATS64 support Date: Thu, 11 Mar 2010 12:26:39 -0800 (PST) Message-ID: <20100311.122639.258785986.davem@davemloft.net> References: <1268337450-6749-1-git-send-email-jengelh@medozas.de> <1268337450-6749-4-git-send-email-jengelh@medozas.de> <20100311121239.14944fd5@nehalam> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: jengelh@medozas.de, netdev@vger.kernel.org To: shemminger@vyatta.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:60334 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758145Ab0CKU0S (ORCPT ); Thu, 11 Mar 2010 15:26:18 -0500 In-Reply-To: <20100311121239.14944fd5@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: From: Stephen Hemminger Date: Thu, 11 Mar 2010 12:12:39 -0800 > On Thu, 11 Mar 2010 20:57:29 +0100 > Jan Engelhardt wrote: > >> `ip -s link` shows interface counters truncated to 32 bit. This is >> because interface statistics are transported only in 32-bit quantity >> to userspace. This commit adds a new IFLA_STATS64 attribute that >> exports them in full 64 bit. >> >> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html >> Signed-off-by: Jan Engelhardt >> > > What is the point since net_device_stats has only 32 bit counters. > The last time this came up the issue was is that is not possible > to atomically increment a 64 bit counter on most 32 bit platforms. On 64-bit it has 64-bit counters, yet we only report 32-bit counters to userspace via netlink even in that case. That's what Jan is fixing here.