This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] Re: VM hung after running sometime

To: MaoXiaoyun <tinnycloud@xxxxxxxxxxx>
Subject: Re: [Xen-devel] Re: VM hung after running sometime
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Wed, 29 Sep 2010 09:12:07 -0700
Cc: xen devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, keir.fraser@xxxxxxxxxxxxx
Delivery-date: Wed, 29 Sep 2010 09:12:57 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <BAY121-W512F127F0819CA2E5DC3D2DA670@xxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <C8BE230D.239BA%keir.fraser@xxxxxxxxxxxxx>, , <4C98EB42.4020808@xxxxxxxx>, <BAY121-W10DFCBC2F3B78D89381527DA600@xxxxxxx>, , <4C994B08.7050509@xxxxxxxx> <BAY121-W688EF9F79369127219FB3DA600@xxxxxxx>, , <4C9A4B7A.3010308@xxxxxxxx>, <BAY121-W31394CA05B46D94F7DC8F8DA610@xxxxxxx>, <4C9BE0A9.40709@xxxxxxxx>, <BAY121-W4337007E1CA28BC7E72547DA660@xxxxxxx> <BAY121-W2087D6896693255FFB54C2DA660@xxxxxxx>, <4CA220D0.7070309@xxxxxxxx> <BAY121-W512F127F0819CA2E5DC3D2DA670@xxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20100921 Fedora/3.1.4-1.fc13 Lightning/1.0b3pre Thunderbird/3.1.4
 On 09/28/2010 11:01 PM, MaoXiaoyun wrote:
> Well, I just go throught the source of irqbalance, it shows that it
> balances the irq through
> updating /proc/irq/$irq/smp_affinity. That, in my understanding, set
> irq affinity is almost
> equal to irq migration.


> I later find the NIC interrupt is not modified in dom0, so it is safe
> to set its affinity,
> but interrupt of xen event use handle_level_irq, set its affinity will
> subject to irq
> lost.
> Am I right?

I can't parse that sentence so I'm not sure. But if you have
successfully migrated the interrupt/evtchn to a different vcpu, then
there's no subsequent risk of lost events. The event loss can only
happen in the circumstance I mentioned earlier: when you migrate while
an event is being handled, and a second event occurs on the new cpu
before the first one has finished. So you need both bad timing and a
fairly high event delivery rate to trigger the problem.


Xen-devel mailing list