Please forgive me for not being able to understand why setting
memory.low for Type_A can solve the problem.
In my scene, Type_A is the most important, so I will set 100G to memory.low.
But 'memory.low' only takes effect passively when the kernel is
reclaiming memory. It means that reclaim Type_B's memory only when
Type_A in alloc memory slow path. This will affect Type_A's
performance.
We want to reclaim Type_B's memory in advance when A is expected to be busy.