Eyal Moscovici <EYALMO@xxxxxxxxxx> writes: ... > > We can start to implement polling, but I am unsure if the cgroups > integration > will be sufficient. The polling vhost thread should be scheduled all > the time and just moving it from one cgroup to the other wont be > sufficient. > I think it needs a deeper integration to the point where either we have a > vhost thread for each cgroup or the vhost thread enforces the cgroup > policies over its polled VM guests. Agreed, what we have with cgroups is not sufficient. I am waiting for Tejun et al to comment on our approach :) Michael mentioned whether it's possible to integrate cgroups into workgroups which I think is a more generic and the preferred solution. I just don't know yet how easy/difficult it is to implement this with the new cgroups unified hierarchy. BTW, I am working on the numbers you had asked for. Honestly, I think the cost of cgroups could be similar to running a vhost thread/guest since that is how cgroups integration currently works. But it's good to have the numbers before us. >> >> So simple polling by vhost is kind of ok for some guests, but I think to >> really make it work for a reasonably wide selection of guests/workloads >> you need to combine it with 1. polling the NIC - it makes no sense to me >> to only poll one side of the equation; and probably 2. - polling in >> guest. >> > > I agree that we need polling on the NIC which could probably be achieved > by using > the polling interface introduced in kernel 3.11: > http://lwn.net/Articles/551284/ > although I never tried using it myself. > About your point about polling inside the guest, I think it is orthogonal > to polling > in the host. > > > Eyal Moscovici > HL-Cloud Infrastructure Solutions > IBM Haifa Research Lab -- 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
