hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
CVE: NA

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Memory allocation from buddy system will fallback to unmirrored memory if
mirrored memory is not enough and reliable memory fallback is closed.
___GFP_NOFAIL flag will be checked in prepare_before_alloc().

Fixes: 45bd608e ("mm: Introduce watermark check for memory reliable")
Signed-off-by: NMa Wupeng <mawupeng1@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>