The patch titled
Subject: mm: pvmw: add support for walking devmap pages
has been added to the -mm tree. Its filename is
mm-pvmw-add-support-for-walking-devmap-pages.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-pvmw-add-support-for-walking-devmap-pages.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-pvmw-add-support-for-walking-devmap-pages.patch
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------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: pvmw: add support for walking devmap pages
The devmap pages can not use page_vma_mapped_walk() to check if a huge
devmap page is mapped into a vma. Add support for walking huge devmap
pages so that DAX can use it in the next patch.
Link: https://lkml.kernel.org/r/20220403053957.10770-5-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: Ross Zwisler <zwisler@xxxxxxxxxx>
Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx>
Cc: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_vma_mapped.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
--- a/mm/page_vma_mapped.c~mm-pvmw-add-support-for-walking-devmap-pages
+++ a/mm/page_vma_mapped.c
@@ -210,16 +210,10 @@ restart:
*/
pmde = READ_ONCE(*pvmw->pmd);
- if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
+ if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde) ||
+ (pmd_present(pmde) && pmd_devmap(pmde))) {
pvmw->ptl = pmd_lock(mm, pvmw->pmd);
pmde = *pvmw->pmd;
- if (likely(pmd_trans_huge(pmde))) {
- if (pvmw->flags & PVMW_MIGRATION)
- return not_found(pvmw);
- if (!check_pmd(pmd_pfn(pmde), pvmw))
- return not_found(pvmw);
- return true;
- }
if (!pmd_present(pmde)) {
swp_entry_t entry;
@@ -232,6 +226,13 @@ restart:
return not_found(pvmw);
return true;
}
+ if (likely(pmd_trans_huge(pmde) || pmd_devmap(pmde))) {
+ if (pvmw->flags & PVMW_MIGRATION)
+ return not_found(pvmw);
+ if (!check_pmd(pmd_pfn(pmde), pvmw))
+ return not_found(pvmw);
+ return true;
+ }
/* THP pmd was split under us: handle on pte level */
spin_unlock(pvmw->ptl);
pvmw->ptl = NULL;
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-hugetlb_vmemmap-introduce-arch_want_hugetlb_page_free_vmemmap.patch
arm64-mm-hugetlb-enable-hugetlb_page_free_vmemmap-for-arm64.patch
mm-hugetlb_vmemmap-cleanup-hugetlb_vmemmap-related-functions.patch
mm-hugetlb_vmemmap-cleanup-hugetlb_free_vmemmap_enabled.patch
mm-hugetlb_vmemmap-cleanup-config_hugetlb_page_free_vmemmap.patch
mm-rmap-fix-cache-flush-on-thp-pages.patch
dax-fix-cache-flush-on-pmd-mapped-pages.patch
mm-rmap-introduce-pfn_mkclean_range-to-cleans-ptes.patch
mm-pvmw-add-support-for-walking-devmap-pages.patch
dax-fix-missing-writeprotect-the-pte-entry.patch
mm-simplify-follow_invalidate_pte.patch
