Update wording on priorities.

Author: bwsalmon

keps/sig-node/5620-resizing-balloon/README.md

@@ -224,7 +224,7 @@ Consider including folks who also work outside the SIG or subproject.
 In general balloon pods will look just like any other pod. They will be scheduled by a daemon set controller and have reservations and limits like any other pod. They will run in the kube-system namespace as system components. The two distinctions are as follows:
 
  - Balloon pods will be labelled so that monitoring tools can know that the space consumed by the balloon pod "doesn't exist" instead of being "space consumed by a workload". This will be a well known label and potentially require updates to the statistics collection in the Kubernetes master nodes.
- - Balloon pods will run at a special priority level (system-balloon) which mostly acts like system-node-critical, but instead of preempting other pods on upsize, balloon pods will fail to upsize. This distinction is critical because while the balloon pod should never be preempted (since the underlying capacity "doesn't exist"), we upsize them when we are reclaiming unused space, so if another pod ends up using this space before we reclaim it, we don't want to pre-empt the pod, which would impact a runnin workload, we'd rather fail the reclaim, since we were clearly wrong about it not being needed.
+ - Balloon pods will run at a special priority level (system-balloon) which mostly acts like system-node-critical, but instead of preempting other pods on upsize, balloon pods will fail to upsize. This distinction is critical because while the balloon pod should never be preempted (since the underlying capacity "doesn't exist"), we upsize them when we are reclaiming unused space, so if another pod ends up using this space before we reclaim it, we don't want to pre-empt the pod, which would impact a runnin workload, we'd rather fail the reclaim, since we were clearly wrong about it not being needed. Note that the preemption we are discussing is done by Kubelet, not by the scheduler.
 
 ## Metrics details