Messages in this thread | | | From | Michel Lespinasse <> | Subject | [PATCH 0/2] page munlock issues when breaking up COW | Date | Mon, 7 Feb 2011 16:47:34 -0800 |
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It looks like there is a race in the do_wp_page() code that munlocks the old page after breaking up COW. The pte still points to that old page, so I don't see that we are protected against vmscan mlocking back the page right away. This can be easily worked around by moving that code to the end of do_wp_page(), after the pte has been pointed to the new page.
Also, the corresponding code in __do_fault() seems entirely unnecessary, since there was never a pte pointing to the old page in our vma.
Michel Lespinasse (2): mlock: fix race when munlocking pages in do_wp_page() mlock: do not munlock pages in __do_fault()
mm/memory.c | 32 ++++++++++++-------------------- 1 files changed, 12 insertions(+), 20 deletions(-)
-- 1.7.3.1
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