[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PROPOSAL] Event channel for SMP-VMs: per-vCPU or per-OS?
On Wed, Oct 30, 2013 at 8:45 AM, Roger Pau Monné <roger.pau@xxxxxxxxxx> wrote:
In current implementation, the event pending map is global to all vCPUs, but only one vCPU is enabled to "see" that event's status (vCPU0 by default).
My idea is to enable all vCPUs to see such event. The I/O event is actually delivered to the whole OS, and we select the best vCPU to tickle.
Hmm.. yes it can happen, but it seems to be the corner case, not the common case.
I am trying to compare how interrupts are handled in physical SMP systems and then think about how we can do better in virtual SMP systems.
In physical SMP, Linux OS commonly relies on "irqbalance" daemon: remap interrupts every few seconds, which is too coarse for SMP-VMs, because
hypervisor schedules vCPUs in tens of milliseconds. I am not familiar with FreeBSD, does it have a similar functionality as
irqbalance?
Thanks, Luwei _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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