From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: [bug] forcedeth: hung interface under load Date: Tue, 3 Apr 2007 09:05:14 +0200 Message-ID: <20070403070514.GA22940@elte.hu> References: <20070402115325.GA945@elte.hu> <20070403062629.GA13210@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: akpm@linux-foundation.org, jeff@garzik.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Adrian Bunk To: Ayaz Abdulla Return-path: Received: from mx2.mail.elte.hu ([157.181.151.9]:39083 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753416AbXDCHFe (ORCPT ); Tue, 3 Apr 2007 03:05:34 -0400 Content-Disposition: inline In-Reply-To: <20070403062629.GA13210@elte.hu> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org * Ingo Molnar wrote: > > > I had responded eariler to the thread asking you to try out the patch > > found in bug 8058: > > http://bugzilla.kernel.org/show_bug.cgi?id=8058 > > > > I believe that is the caush of the NULL skb dereference issue. > > there's a different type of regression now: under high load i dont get > a crash, i get a hung interface instead. No error packets or other > weird interface state - just a hung interface. [...] the interface stats do not change from that point on: eth1 Link encap:Ethernet HWaddr 00:13:D4:DC:41:12 inet addr:10.0.1.12 Bcast:10.0.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:14976 errors:0 dropped:0 overruns:0 frame:0 TX packets:3928743 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1028544 (1004.4 KiB) TX bytes:4126766510 (3.8 GiB) Interrupt:16 Base address:0xa000 and the irq count does not change either: 16: 816 3463148 IO-APIC-fasteoi eth1 no matter what i do to the interface. So it's completely stuck. No kernel messages either - apparently nv_tx_timeout() never triggered. note, the hang occurs faster if you set max_interrupt_work to a really low value (such as 0). [ The hang occurs _much_ faster if you apply the -rt patch and enable PREEMPT_RT - but the hang occurs on mainline too. ] Ingo