hulk inclusion
category: feature
bugzilla: N/A

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Support alloc memory from nodes.

mg_sp_alloc allow to alloc memory from one node.
If the node have no enough memory, the caller would
pick a next node. But that has a lot of overhead.

To improve performance, we support a new interface to
alloc memory from nodes.
Signed-off-by: NChen Jun <chenjun102@huawei.com>