On 05/02/2015 19:55, Jan Kiszka wrote: > > This patch introduces a new module parameter for the KVM module; when it > > is present, KVM attempts a bit of polling on every HLT before scheduling > > itself out via kvm_vcpu_block. > > Wouldn't it be better to tune this on a per-VM basis? Think of mixed > workloads with some latency-sensitive and some standard VMs. Yes, but: 1) this turned out to be very cheap, so a per-host tunable is not too bad; 2) it also affects only very few workloads (for example network workloads can already do polling in the guest) so it only affects few people; 3) long term anyway we want it to auto tune, which is better than tuning it per-VM. Paolo -- 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