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author | Ingo Molnar <mingo@kernel.org> | 2018-07-17 09:27:43 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-07-17 09:27:43 +0200 |
commit | 52b544bd386688177c41d53e748111c29d0ccc98 (patch) | |
tree | c2083582176e773084364af93cc44e0f94b6cde8 /mm/rmap.c | |
parent | afed7bcf9487bb28e2e2b016a195085c07416c0b (diff) | |
parent | 9d3cce1e8b8561fed5f383d22a4d6949db4eadbe (diff) | |
download | linux-52b544bd386688177c41d53e748111c29d0ccc98.tar.gz |
Merge tag 'v4.18-rc5' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r-- | mm/rmap.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 6db729dc4c50..eb477809a5c0 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -64,6 +64,7 @@ #include <linux/backing-dev.h> #include <linux/page_idle.h> #include <linux/memremap.h> +#include <linux/userfaultfd_k.h> #include <asm/tlbflush.h> @@ -1481,11 +1482,16 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, set_pte_at(mm, address, pvmw.pte, pteval); } - } else if (pte_unused(pteval)) { + } else if (pte_unused(pteval) && !userfaultfd_armed(vma)) { /* * The guest indicated that the page content is of no * interest anymore. Simply discard the pte, vmscan * will take care of the rest. + * A future reference will then fault in a new zero + * page. When userfaultfd is active, we must not drop + * this page though, as its main user (postcopy + * migration) will not expect userfaults on already + * copied pages. */ dec_mm_counter(mm, mm_counter(page)); /* We have to invalidate as we cleared the pte */ |