| Date | Tue, 08 Sep 2009 14:59:21 -0400 | From | Rik van Riel <> | Subject | Re: [PATCH 4/8] mm: FOLL_DUMP replace FOLL_ANON |
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Hugh Dickins wrote: > The "FOLL_ANON optimization" and its use_zero_page() test have caused > confusion and bugs: why does it test VM_SHARED? for the very good but > unsatisfying reason that VMware crashed without. As we look to maybe > reinstating anonymous use of the ZERO_PAGE, we need to sort this out. > > Easily done: it's silly for __get_user_pages() and follow_page() to > be guessing whether it's safe to assume that they're being used for > a coredump (which can take a shortcut snapshot where other uses must > handle a fault) - just tell them with GUP_FLAGS_DUMP and FOLL_DUMP. > > get_dump_page() doesn't even want a ZERO_PAGE: an error suits fine. > > Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Rik van Riel <riel@redhat.com>
-- All rights reversed.
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