I originally intended to simply submit this as a patch, but contributing.md seemed to suggest non-members are not welcome to do so directly and instead prefer to open issues here? (apologies if that's not accurate).
The stats pull-model for existing virtio-balloon suffers from liveliness issues when attempting to do proactive shrinking of a fleet of guests. If the balloon over-pressures a guest and causes disk thrashing without OOM, this is a condition that can cause future polls to hang for a bit or even cause liveliness issues in general.
I was looking to propose a push-model for stats which the host can request the guest report stats on an interval, which resolves liveliness questions and allows for a more responsive host-balloon control loop.
gourryinverse@4896e7b
I've posted the kernel extension proposal here (along with an extension to the stats to include more useful stats including psi):
https://lore.kernel.org/virtualization/20260513165006.2790857-1-gourry@gourry.net/T/#mba871d66481713764437a8cfd1743952edba4785
I originally intended to simply submit this as a patch, but contributing.md seemed to suggest non-members are not welcome to do so directly and instead prefer to open issues here? (apologies if that's not accurate).
The stats pull-model for existing virtio-balloon suffers from liveliness issues when attempting to do proactive shrinking of a fleet of guests. If the balloon over-pressures a guest and causes disk thrashing without OOM, this is a condition that can cause future polls to hang for a bit or even cause liveliness issues in general.
I was looking to propose a push-model for stats which the host can request the guest report stats on an interval, which resolves liveliness questions and allows for a more responsive host-balloon control loop.
gourryinverse@4896e7b
I've posted the kernel extension proposal here (along with an extension to the stats to include more useful stats including psi):
https://lore.kernel.org/virtualization/20260513165006.2790857-1-gourry@gourry.net/T/#mba871d66481713764437a8cfd1743952edba4785