[memory management] always call all squeezers when memory is short. Even if amount requested has been consumed. This allows squeezers that mind the quota (cli history) to give what they can, but also allows those that don't mind the quota (mem_cache) to always give what they can.
Theoretically, once we reach the quota we can stop. But in practice, reaching the quota is sometimes insufficient (e.g. fragmentation).
[mem cache] support squeezing mem caches when memory is short