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?
> Date: Tue, 28 Sep 2010 10:07:28 -0700 > From: jeremy@xxxxxxxx > To: tinnycloud@xxxxxxxxxxx > CC: xen-devel@xxxxxxxxxxxxxxxxxxx; keir.fraser@xxxxxxxxxxxxx > Subject: Re: [Xen-devel] Re: VM hung after running sometime > > On 09/28/2010 04:23 AM, MaoXiaoyun wrote: > > > > Is it safe to set irq affinity(including NIC, domain event, etc) manually? > > Will it cause irq lost? > > There's only a very small chance of a lost interrupt, especially if the > device is mostly idle at the time. The event can only be lost if: > > 1. it is handling a device interrupt > 2. you migrate it to another cpu > 3. another interrupt comes in before the first one has finished > processing > > J >
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