About used-once anon-pages

Hi, Kim,

From the commit log of the commit b518154e59aa ("mm/vmscan: protect the
workingset on anonymous LRU"), you referred to the "used-once"
anon-pages.  I have known about the use cases about used-once file cache
pages.  But I don't know the use cases about the used-once anon-pages.
Can you teach me about that?

Or you doesn't mean used-once exactly, but accessing the pages for a
while after allocating the page, then never touch it again?

Best Regards,
Huang, Ying