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| author | David S. Miller <davem@davemloft.net> | 2018-07-20 14:45:10 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-07-20 21:17:12 -0700 |
| commit | c4c5551df136a7c4edd7c2f433d9a296b39826a2 (patch) | |
| tree | a33d9f228efd34b0ad18e380385093405ef72d98 /mm/rmap.c | |
| parent | 40999f11ce677ce3c5d0e8f5f76c40192a26b479 (diff) | |
| parent | 48e5aee81f320da8abd1f09c8410f584315f59b0 (diff) | |
| download | linux-c4c5551df136a7c4edd7c2f433d9a296b39826a2.tar.bz2 | |
Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux
All conflicts were trivial overlapping changes, so reasonably
easy to resolve.
Signed-off-by: David S. Miller <davem@davemloft.net>
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 */ |