On 23.09.23 03:31, Suren Baghdasaryan wrote:
From: Andrea Arcangeli <aarca...@redhat.com>
As far as the rmap code is concerned, UFFDIO_REMAP only alters the
page->mapping and page->index. It does it while holding the page
lock. However folio_referenced() is doing rmap walks without taking the
folio lock first, so folio_lock_anon_vma_read() must be updated to
re-check that the folio->mapping didn't change after we obtained the
anon_vma read lock.
I'm curious: why don't we need this for existing users of
page_move_anon_rmap()? What's special about UFFDIO_REMAP?
--
Cheers,
David / dhildenb
