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authorIngo Molnar <mingo@kernel.org>2013-11-01 08:10:58 +0100
committerIngo Molnar <mingo@kernel.org>2013-11-01 08:24:41 +0100
commitfb10d5b7efbcc0aa9e46a9aa5ad86772c7bacb9a (patch)
treeea284fe7b9c17a85b8d3c4ba999d6e26d51a12f6 /mm/huge_memory.c
parentf9f9ffc237dd924f048204e8799da74f9ecf40cf (diff)
parent52469b4fcd4fc433ffc78cec4cf94368e9052890 (diff)
downloadlinux-fb10d5b7efbcc0aa9e46a9aa5ad86772c7bacb9a.tar.bz2
Merge branch 'linus' into sched/core
Resolve cherry-picking conflicts: Conflicts: mm/huge_memory.c mm/memory.c mm/mprotect.c See this upstream merge commit for more details: 52469b4fcd4f Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r--mm/huge_memory.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1be2a1f95b61..2612f60f53ee 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2756,6 +2756,7 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
+again:
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
spin_lock(&mm->page_table_lock);
if (unlikely(!pmd_trans_huge(*pmd))) {
@@ -2778,7 +2779,14 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
split_huge_page(page);
put_page(page);
- BUG_ON(pmd_trans_huge(*pmd));
+
+ /*
+ * We don't always have down_write of mmap_sem here: a racing
+ * do_huge_pmd_wp_page() might have copied-on-write to another
+ * huge page before our split_huge_page() got the anon_vma lock.
+ */
+ if (unlikely(pmd_trans_huge(*pmd)))
+ goto again;
}
void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,