[PATCH 4/7] mm,ksm: FOLL_MIGRATION do migration_entry_wait

In "ksm: remove old stable nodes more thoroughly" I said that I'd never seen its WARN_ON_ONCE(page_mapped(page)). True at the time of writing, but it soon appeared once I tried fuller tests on the whole series. It turned out to be due to the KSM page migration itself: unmerge_and_

[PATCH 4/7] mm,ksm: FOLL_MIGRATION do migration_entry_wait

In ksm: remove old stable nodes more thoroughly I said that I'd never seen its WARN_ON_ONCE(page_mapped(page)). True at the time of writing, but it soon appeared once I tried fuller tests on the whole series. It turned out to be due to the KSM page migration itself: unmerge_and_