From: "Denys Fedoryshchenko" Subject: Re: circular locking, mirred, 2.6.24.2 Date: Thu, 6 Mar 2008 17:50:59 +0200 Message-ID: <20080306143910.M91001@visp.net.lb> References: <20080224222035.M62480@visp.net.lb> <20080225095646.GA4321@ff.dom.local> <20080225104652.M2446@visp.net.lb> <20080225113930.GA4733@ff.dom.local> <20080305103935.M76165@visp.net.lb> <20080306134015.GA4571@ff.dom.local> <20080306135625.M25627@visp.net.lb> <1204813634.4440.59.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Cc: Jarek Poplawski , netdev@vger.kernel.org To: hadi@cyberus.ca Return-path: Received: from usermail.globalproof.net ([194.146.153.18]:52153 "EHLO usermail.globalproof.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755207AbYCFPvS (ORCPT ); Thu, 6 Mar 2008 10:51:18 -0500 In-Reply-To: <1204813634.4440.59.camel@localhost> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 06 Mar 2008 09:27:14 -0500, jamal wrote > On Thu, 2008-06-03 at 15:57 +0200, Denys Fedoryshchenko wrote: > > I am able to reproduce this warning over this relatively simple shell script > > on my Gentoo PC (2.6.25-rc3). > > http://www.nuclearcat.com/files/bug_feb.txt > > > > That script looks pretty sane to me - nothing super-exciting. I suspect > you eventually want them all to look like ifb1 on the egress. > Do you see the same issue without the ifb1 speacial case? Well, i am able to reproduce in much more trivial script. Tested 2.6.25-rc4 also. modprobe ifb ifconfig ifb0 up TC=/sbin/tc $TC qdisc del dev eth0 ingress 1>/dev/null 2>/dev/null $TC qdisc add dev eth0 ingress ${TC} filter add dev eth0 parent ffff: protocol ip prio 10 u32 \ match u32 0 0 flowid 1:1 \ action mirred egress redirect dev ifb0 > > > Probably it will help to debug issue for more experienced developers. Note: > > it appears not immediately, second time i tested, it's appeared after while, > > but in matter of seconds. > > I wonder is there some latency from the moment you insmod ifb to the > moment the tc rules take effect? Will it still happen if you dont > have modules? Also note, that lock dependency is a bit strange, > Jarek correct me if i am wrong; it seems to say: a packet received > on ingress of some e1000 (ethx) gets acted on by mirred which ends > grabbing lock of an ifb device - this part should be fine and no > need for the alarm. The alarm seems to be a result of a loopback > device that is being registered in between the two activities. > i.e there are three devices affected with entirely different > locks(ethx, ifbx, and loopback). Smells like lockdep is getting it wrong? No idea, i have strange lockup's on my systems where i have ifb, and that make me worry. And i feel it is directly related with my love to use ifb devices and way how i am using them. > > > Note - it can stop traffic on PC completely. It is also seems crashed my > > desktop PC, i am not able to execute "tc qdisc del dev eth0 root". > > The system hang completely. I had few similar issues on my PPPoE servers > > (with different scripts for shapers), that system hang, and even "reboot - f" > > doesn't work sometimes. > > This sounds like a different issue from above - when did this start > to happen? Is it at the same time as above warnings showing up? Yes, it is different issue seems, it is rare to lockup system , and i will dig more, to understand how it is happening. > > cheers, > jamal > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Denys Fedoryshchenko Technical Manager Virtual ISP S.A.L.