[PATCHv2 16/28] thp: handle file pages in mremap()
From: Kirill A. Shutemov <hidden>
Date: 2016-02-11 14:23:18
Also in:
lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
We need to mirror logic in move_ptes() wrt need_rmap_locks to get proper serialization file THP. Signed-off-by: Kirill A. Shutemov <redacted> --- mm/mremap.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/mm/mremap.c b/mm/mremap.c
index 8eeba02fc991..b43027a25982 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c@@ -193,17 +193,27 @@ unsigned long move_page_tables(struct vm_area_struct *vma, break; if (pmd_trans_huge(*old_pmd)) { if (extent == HPAGE_PMD_SIZE) { + struct address_space *mapping = NULL; + struct anon_vma *anon_vma = NULL; bool moved; - VM_BUG_ON_VMA(vma->vm_file || !vma->anon_vma, - vma); /* See comment in move_ptes() */ - if (need_rmap_locks) - anon_vma_lock_write(vma->anon_vma); + if (need_rmap_locks) { + if (vma->vm_file) { + mapping = vma->vm_file->f_mapping; + i_mmap_lock_write(mapping); + } + if (vma->anon_vma) { + anon_vma = vma->anon_vma; + anon_vma_lock_write(anon_vma); + } + } moved = move_huge_pmd(vma, new_vma, old_addr, new_addr, old_end, old_pmd, new_pmd); - if (need_rmap_locks) - anon_vma_unlock_write(vma->anon_vma); + if (anon_vma) + anon_vma_unlock_write(anon_vma); + if (mapping) + i_mmap_unlock_write(mapping); if (moved) { need_flush = true; continue;
--
2.7.0
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