mm: Add reliable memory use limit for user tasks

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S


CVE: NA

--------------------------------

There is a upper limit for all memory allocation if the following condtions
are met:
- gfp_zone(gfp & ~ GFP_RELIABLE) == ZONE_MOVABLE
- gfp & GFP_RELIABLE is true

Init tasks will alloc memory from non-mirrored region if their allocation
trigger limit.

The limit can be set or access via /proc/sys/vm/task_reliable_limit

This limit's default value is ULONG_MAX. User can update this value between
current user used reliable memory size and total reliable memory size.

Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>