On Tue, 6 Dec 2016, Stefano Stabellini wrote: > moving a vCPU with interrupts assigned to it is slower than moving a > vCPU without interrupts assigned to it. You could say that the > slowness is directly proportional do the number of interrupts assigned > to the vCPU.
To be pedantic, by "assigned" I mean that a physical interrupt is routed to a given pCPU and is set to be forwarded to a guest vCPU running on it by the _IRQ_GUEST flag. The guest could be dom0. Upon receiving one of these physical interrupts, a corresponding virtual interrupt (could be a different irq) will be injected into the guest vCPU. When the vCPU is migrated to a new pCPU, the physical interrupts that are configured to be injected as virtual interrupts into the vCPU, are migrated with it. The physical interrupt migration has a cost. However, receiving physical interrupts on the wrong pCPU has an higher cost. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
