This commit adds a new DAMOS action called 'LRU_PRIO' for the physical
address space.  The action prioritizes pages in the memory regions of the
user-specified target access pattern on their LRU lists.  This is hence
supposed to be used for frequently accessed (hot) memory regions so that
hot pages could be more likely protected under memory pressure. 
Internally, it simply calls 'mark_page_accessed()'.

Link: https://lkml.kernel.org/r/20220613192301.8817-5-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>