From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754844AbYFAUqf (ORCPT ); Sun, 1 Jun 2008 16:46:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751950AbYFAUqY (ORCPT ); Sun, 1 Jun 2008 16:46:24 -0400 Received: from elasmtp-spurfowl.atl.sa.earthlink.net ([209.86.89.66]:45940 "EHLO elasmtp-spurfowl.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751646AbYFAUqX (ORCPT ); Sun, 1 Jun 2008 16:46:23 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=mindspring.com; b=VISCHmW4V1Aib29JrROOP8TeBVBj01hGwLLKfPqB/Mm3pMU7xLsFCCMkZqLdHuxs; h=Received:Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-ELNK-Trace:X-Originating-IP; Date: Sun, 1 Jun 2008 16:46:14 -0400 From: Bill Fink To: Ben Hutchings Cc: Alan Cox , James Cammarata , Andrew Morton , linux-kernel@vger.kernel.org, Linux Netdev List Subject: Re: [PATCH] net: add ability to clear stats via ethtool - e1000/pcnet32 Message-Id: <20080601164614.012fe1f6.billfink@mindspring.com> In-Reply-To: <20080601014620.GG30769@solarflare.com> References: <482F610D.2080108@sngx.net> <20080518003104.GK28241@solarflare.com> <482FBA09.80201@sngx.net> <483E0AAE.2020107@sngx.net> <20080528221118.63da4092.akpm@linux-foundation.org> <483EA2D1.8050603@sngx.net> <20080529154525.3916c7b5@core> <20080530151250.b44a119a.billfink@mindspring.com> <20080531131143.516ca56e@core> <20080531195702.0b879dd1.billfink@mindspring.com> <20080601014620.GG30769@solarflare.com> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.8.6; powerpc-yellowdog-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-ELNK-Trace: c598f748b88b6fd49c7f779228e2f6aeda0071232e20db4dac18abcc869161409d3132443b483de5350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 96.234.158.248 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 1 Jun 2008, Ben Hutchings wrote: > Bill Fink wrote: > > > Yes, every individual Linux network administrator can re-create the > > wheel by devising their own scripts, but it makes much more sense > > to me to implement a simple general kernel mechanism once that could > > be used generically, than to have hundreds (or thousands) of Linux > > network administrators each having to do it themselves (perhaps > > multiple times if they have a variety of types of systems and types > > of NICs). > > The ethtool interface is pretty generic, even if the names aren't. > Here's some Python code I just knocked up which demonstrates how > to get a set of named stats. It shouldn't be terribly hard to > extend this to saving and subtracting stat sets. I'm not sure what that proves. Your python code just basically gives the same info as running the "ethtool -S" command. But the question is how does one devise a generic script or tool that doesn't require any special knowledge of the specific NIC being used. For example, here's the "ethtool -S" info for my myri10ge NIC: [root@chance8 ~]# ethtool -S eth2 NIC statistics: rx_packets: 53243864310 tx_packets: 112826823797 rx_bytes: 301727733072710 tx_bytes: 716648208451198 rx_errors: 0 tx_errors: 0 rx_dropped: 0 tx_dropped: 0 multicast: 0 collisions: 0 rx_length_errors: 0 rx_over_errors: 0 rx_crc_errors: 0 rx_frame_errors: 0 rx_fifo_errors: 0 rx_missed_errors: 0 tx_aborted_errors: 0 tx_carrier_errors: 0 tx_fifo_errors: 0 tx_heartbeat_errors: 0 tx_window_errors: 0 tx_boundary: 4096 WC: 1 irq: 8413 MSI: 1 read_dma_bw_MBs: 1398 write_dma_bw_MBs: 1613 read_write_dma_bw_MBs: 2711 serial_number: 287046 tx_pkt_start: 1157674101 tx_pkt_done: 1157674101 tx_req: 188226127 tx_done: 188226127 rx_small_cnt: 3009560676 rx_big_cnt: 1726230729 wake_queue: 57969440 stop_queue: 57969440 watchdog_resets: 0 tx_linearized: 0 link_changes: 8 link_up: 1 dropped_link_overflow: 0 dropped_link_error_or_filtered: 26584 dropped_multicast_filtered: 2190912 dropped_runt: 0 dropped_overrun: 0 dropped_no_small_buffer: 0 dropped_no_big_buffer: 0 How does one know which of these reported values are counter stats that one wishes to zero/snapshot, and which are not? Another issue that occurred to me is if multiple people are working on troubleshooting a network problem, how do we insure that they all get a consistent view of the stats? If this is done via a kernel mechanism then there isn't an issue. But if it's done via user space, then you have to make sure that everyone zeros/snapshots the stats at the same time. Ideally, one should be able to do something like "ethtool -z ethX" to zero/snapshot the driver stats, and then "ethtool -S ethX" to get the stats since the last snapshot. You should be able to use the same tool ("ethtool") to do all of this, and not some other special tool or specially devised homegrown script. Why make users lives any more difficult than need be? -Bill