The patch titled
Subject: mm: adjust FOLL_SPLIT for new refcounting
has been removed from the -mm tree. Its filename was
mm-adjust-foll_split-for-new-refcounting.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mm: adjust FOLL_SPLIT for new refcounting
We need to prepare kernel to allow transhuge pages to be mapped with
ptes too. We need to handle FOLL_SPLIT in follow_page_pte().
Also we use split_huge_page() directly instead of split_huge_page_pmd().
split_huge_page_pmd() will gone.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Tested-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Jerome Marchand <jmarchan@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Steve Capper <steve.capper@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/gup.c | 67 ++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 49 insertions(+), 18 deletions(-)
diff -puN mm/gup.c~mm-adjust-foll_split-for-new-refcounting mm/gup.c
--- a/mm/gup.c~mm-adjust-foll_split-for-new-refcounting
+++ a/mm/gup.c
@@ -116,6 +116,19 @@ retry:
}
}
+ if (flags & FOLL_SPLIT && PageTransCompound(page)) {
+ int ret;
+ get_page(page);
+ pte_unmap_unlock(ptep, ptl);
+ lock_page(page);
+ ret = split_huge_page(page);
+ unlock_page(page);
+ put_page(page);
+ if (ret)
+ return ERR_PTR(ret);
+ goto retry;
+ }
+
if (flags & FOLL_GET)
get_page_foll(page);
if (flags & FOLL_TOUCH) {
@@ -220,27 +233,45 @@ struct page *follow_page_mask(struct vm_
}
if ((flags & FOLL_NUMA) && pmd_protnone(*pmd))
return no_page_table(vma, flags);
- if (pmd_trans_huge(*pmd)) {
- if (flags & FOLL_SPLIT) {
+ if (likely(!pmd_trans_huge(*pmd)))
+ return follow_page_pte(vma, address, pmd, flags);
+
+ ptl = pmd_lock(mm, pmd);
+ if (unlikely(!pmd_trans_huge(*pmd))) {
+ spin_unlock(ptl);
+ return follow_page_pte(vma, address, pmd, flags);
+ }
+
+ if (unlikely(pmd_trans_splitting(*pmd))) {
+ spin_unlock(ptl);
+ wait_split_huge_page(vma->anon_vma, pmd);
+ return follow_page_pte(vma, address, pmd, flags);
+ }
+
+ if (flags & FOLL_SPLIT) {
+ int ret;
+ page = pmd_page(*pmd);
+ if (is_huge_zero_page(page)) {
+ spin_unlock(ptl);
+ ret = 0;
split_huge_page_pmd(vma, address, pmd);
- return follow_page_pte(vma, address, pmd, flags);
- }
- ptl = pmd_lock(mm, pmd);
- if (likely(pmd_trans_huge(*pmd))) {
- if (unlikely(pmd_trans_splitting(*pmd))) {
- spin_unlock(ptl);
- wait_split_huge_page(vma->anon_vma, pmd);
- } else {
- page = follow_trans_huge_pmd(vma, address,
- pmd, flags);
- spin_unlock(ptl);
- *page_mask = HPAGE_PMD_NR - 1;
- return page;
- }
- } else
+ } else {
+ get_page(page);
spin_unlock(ptl);
+ lock_page(page);
+ ret = split_huge_page(page);
+ unlock_page(page);
+ put_page(page);
+ }
+
+ return ret ? ERR_PTR(ret) :
+ follow_page_pte(vma, address, pmd, flags);
}
- return follow_page_pte(vma, address, pmd, flags);
+
+ page = follow_trans_huge_pmd(vma, address, pmd, flags);
+ spin_unlock(ptl);
+ *page_mask = HPAGE_PMD_NR - 1;
+ return page;
}
static int get_gate_page(struct mm_struct *mm, unsigned long address,
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
thp-update-documentation.patch
thp-allow-mlocked-thp-again.patch
mm-prepare-page_referenced-and-page_idle-to-new-thp-refcounting.patch
thp-add-debugfs-handle-to-split-all-huge-pages.patch
thp-increase-split_huge_page-success-rate.patch
thp-fix-split_huge_page-after-mremap-of-thp.patch
memblock-fix-section-mismatch.patch
mm-fix-locking-order-in-mm_take_all_locks.patch
mm-make-optimistic-check-for-swapin-readahead-fix.patch
mm-make-swapin-readahead-to-improve-thp-collapse-rate-fix.patch
mm-make-swapin-readahead-to-improve-thp-collapse-rate-fix-2.patch
mm-make-swapin-readahead-to-improve-thp-collapse-rate-fix-3.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
