On 09/06/2012 02:27 PM, Tomoki Sekiyama wrote: > This RFC patch series provides facility to dedicate CPUs to KVM guests > and enable the guests to handle interrupts from passed-through PCI devices > directly (without VM exit and relay by the host). > > With this feature, we can improve throughput and response time of the device > and the host's CPU usage by reducing the overhead of interrupt handling. > This is good for the application using very high throughput/frequent > interrupt device (e.g. 10GbE NIC). > Real-time applicatoins also gets benefit from CPU isolation feature, which > reduces interfare from host kernel tasks and scheduling delay. > > The overview of this patch series is presented in CloudOpen 2012. > The slides are available at: > http://events.linuxfoundation.org/images/stories/pdf/lcna_co2012_sekiyama.pdf During Plumbers 2012, both Intel and AMD disclosed upcoming features to their processors (APIC-V and AVIC) that allow directing device interrupts to guest vcpus without host kernel involvement. This works without pinning, dedicating a core to a guest, or any special measures beyond support for the feature. CPU isolation is still useful to improve real-time latency further, but this is really independent of kvm. I am inclined to reject this feature in favour of the new hardware support. Sorry, I know this isn't nice to hear, but the extra maintenance burden cannot be justified for a niche use case with special limitations when generally useful feature exploiting proper hardware support provides the same functionality. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
