Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932658Ab3CLPy5 (ORCPT ); Tue, 12 Mar 2013 11:54:57 -0400 Received: from mercuryimc.plus.com ([80.229.200.144]:40044 "EHLO centos1.newflow.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754947Ab3CLPy4 (ORCPT ); Tue, 12 Mar 2013 11:54:56 -0400 Message-ID: <513F4FCE.5090109@mimc.co.uk> Date: Tue, 12 Mar 2013 15:54:54 +0000 From: Mark Jackson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130221 Thunderbird/17.0.3 MIME-Version: 1.0 To: "linux-omap@vger.kernel.org" , lkml Subject: Re: Excessive ethernet interrupts on AM335x board References: <513F4B58.1000204@mimc.co.uk> In-Reply-To: <513F4B58.1000204@mimc.co.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2616 Lines: 67 On 12/03/13 15:35, Mark Jackson wrote: > I'm just fighting an issue with ethernet on our custom AM335x board:- > > # uname -a > Linux nanobone 3.9.0-rc2-00113-gd60f039 #139 Tue Mar 12 15:14:01 GMT 2013 armv7l GNU/Linux > > Every now and then, the whole unit slows to a crawl. The only indication of any problem is:- > > (a) the serial tty port becomes much less responsive > (b) normal ping times jump from 1ms to >10sec (sometimes >20sec !!) > (c) the ethernet interrupt count rockets (see below) > > I've tried to force the problem by flood pinging from my PC. > > # while true >> do grep "58:" /proc/interrupts; sleep 10 >> done > 58: 1291 INTC 4a100000.ethernet <<< normal pinging (about 100 irqs per 10sec) > 58: 1333 INTC 4a100000.ethernet > 58: 1372 INTC 4a100000.ethernet > 58: 3979 INTC 4a100000.ethernet <<< start flood ping (about 4k irqs per 10sec) > 58: 6540 INTC 4a100000.ethernet > 58: 17519 INTC 4a100000.ethernet <<< big jump >>> > 58: 20169 INTC 4a100000.ethernet > 58: 22775 INTC 4a100000.ethernet > 58: 25368 INTC 4a100000.ethernet > 58: 34598 INTC 4a100000.ethernet <<< big jump >>> > 58: 37182 INTC 4a100000.ethernet > 58: 39730 INTC 4a100000.ethernet > 58: 141220 INTC 4a100000.ethernet <<< whoa !!! >>> > 58: 146080 INTC 4a100000.ethernet Doing the flood ping test on an old Beaglebone (running kernel 3.2.34 on an sdcard), I get:- # while true > do grep "94:" /proc/interrupts; sleep 10 ne > done 94: 281353 INTC cpsw.0 94: 370782 INTC cpsw.0 94: 457537 INTC cpsw.0 94: 544876 INTC cpsw.0 94: 631795 INTC cpsw.0 94: 717747 INTC cpsw.0 94: 805974 INTC cpsw.0 94: 892961 INTC cpsw.0 94: 981490 INTC cpsw.0 94: 1070627 INTC cpsw.0 94: 1153086 INTC cpsw.0 94: 1242060 INTC cpsw.0 94: 1327734 INTC cpsw.0 94: 1413705 INTC cpsw.0 94: 1504494 INTC cpsw.0 94: 1591395 INTC cpsw.0 94: 1676769 INTC cpsw.0 So these are going up by 90k irqs per 10sec ... meaning that the AM335x board seems to be *dropping* most of its ethernet irqs. I'll try to get 3.9.0-rc2 on the BB and retest. Mark J. -- 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/