hugetlb: Add huge page allocation limit

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8TKCL


CVE: NA

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The user wants to reserve a certain amount of memory for normal
non-huge page, that is, the hugetlb can't allowed to use all the
memory.

Add a new kernel parameters "hugepage_prohibit_sz=" to set size
for normal non-huge page reserved, and when alloc huge page,
let's fail if the new allocating exceeds the limit.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>