Merge Pull Request from: @ma-wupeng 
 
Introduce new syscall set_mempolicy_home_node and mempolicy
MPOL_PREFERRED_MANY.

This patch series introduces the concept of the MPOL_PREFERRED_MANY mempolicy.
This mempolicy mode can be used with either the set_mempolicy(2) or mbind(2)
interfaces. Like the MPOL_PREFERRED interface, it allows an application to set a
preference for nodes which will fulfil memory allocation requests. Unlike the
MPOL_PREFERRED mode, it takes a set of nodes. Like the MPOL_BIND interface, it
works over a set of nodes. Unlike MPOL_BIND, it will not cause a SIGSEGV or
invoke the OOM killer if those preferred nodes are not available.

mm: add new syscall set_mempolicy_home_node 
 
Link:https://gitee.com/openeuler/kernel/pulls/637 

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> 
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>