Messages in this thread | | | Date | Wed, 12 Nov 2008 14:27:42 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [PATCH 2/4] Add replace_page(), change the mapping of pte from one page into another |
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On Wed, 12 Nov 2008, Andrea Arcangeli wrote:
> On Tue, Nov 11, 2008 at 09:10:45PM -0600, Christoph Lameter wrote: > > get_user_pages() cannot get to it since the pagetables have already been > > modified. If get_user_pages runs then the fault handling will occur > > which will block the thread until migration is complete. > > migrate.c does nothing for ptes pointing to swap entries and > do_swap_page won't wait for them either. Assume follow_page in
If a anonymous page is a swap page then it has a mapping. migrate_page_move_mapping() will lock the radix tree and ensure that no additional reference (like done by do_swap_page) is established during migration.
> However it's not exactly the same bug as the one in fork, I was > talking about before, it's also not o_direct specific. Still
So far I have seen wild ideas not bugs.
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