rk: mm: CMA memory busy error may have a variety of reasons, in the larger one is:

rk: mm: CMA memory busy error may have a variety of reasons, in the larger one is:
the pages being used in the system come from CMA, and now need recycling
them for new CMA allocation, it need to allocate a new page for storing data
that will be reclaim CMA's pages, but new page may also be come from CMA memory
when memory allocate fall back to MIGRATE_CMA freelist.

Now we protect the CMA's pages in the memory fallback allocate

[ 1637.058550] alloc_contig_range test_pages_isolated(431a0, 431c0) failed