The patch titled
Subject: powerpc: gup_hugepte() support THP based tail recounting
has been added to the -mm tree. Its filename is
powerpc-gup_hugepte-support-thp-based-tail-recounting.patch
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------------------------------------------------------
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Subject: powerpc: gup_hugepte() support THP based tail recounting
Up to this point the code assumed old refcounting for hugepages (pre-thp).
This updates the code directly to the thp mapcount tail page refcounting.
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxx>
---
arch/powerpc/mm/hugetlbpage.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff -puN arch/powerpc/mm/hugetlbpage.c~powerpc-gup_hugepte-support-thp-based-tail-recounting arch/powerpc/mm/hugetlbpage.c
--- a/arch/powerpc/mm/hugetlbpage.c~powerpc-gup_hugepte-support-thp-based-tail-recounting
+++ a/arch/powerpc/mm/hugetlbpage.c
@@ -609,12 +609,23 @@ follow_huge_pmd(struct mm_struct *mm, un
return NULL;
}
+static inline void get_huge_page_tail(struct page *page)
+{
+ /*
+ * __split_huge_page_refcount() cannot run
+ * from under us.
+ */
+ VM_BUG_ON(page_mapcount(page) < 0);
+ VM_BUG_ON(atomic_read(&page->_count) != 0);
+ atomic_inc(&page->_mapcount);
+}
+
static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
unsigned long mask;
unsigned long pte_end;
- struct page *head, *page;
+ struct page *head, *page, *tail;
pte_t pte;
int refs;
@@ -637,6 +648,7 @@ static noinline int gup_hugepte(pte_t *p
head = pte_page(pte);
page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
+ tail = page;
do {
VM_BUG_ON(compound_head(page) != head);
pages[*nr] = page;
@@ -655,6 +667,16 @@ static noinline int gup_hugepte(pte_t *p
*nr -= refs;
while (refs--)
put_page(head);
+ } else {
+ /*
+ * Any tail page need their mapcount reference taken
+ * before we return.
+ */
+ while (refs--) {
+ if (PageTail(tail))
+ get_huge_page_tail(tail);
+ tail++;
+ }
}
return 1;
_
Subject: Subject: powerpc: gup_hugepte() support THP based tail recounting
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
mm-compaction-trivial-clean-up-in-acct_isolated.patch
mm-change-isolate-mode-from-define-to-bitwise-type.patch
mm-compaction-make-isolate_lru_page-filter-aware.patch
mm-compaction-make-isolate_lru_page-filter-aware-fix.patch
mm-zone_reclaim-make-isolate_lru_page-filter-aware.patch
mm-zone_reclaim-make-isolate_lru_page-filter-aware-fix.patch
mm-migration-clean-up-unmap_and_move.patch
mremap-check-for-overflow-using-deltas.patch
mremap-avoid-sending-one-ipi-per-page.patch
thp-mremap-support-and-tlb-optimization.patch
thp-mremap-support-and-tlb-optimization-fix.patch
thp-mremap-support-and-tlb-optimization-fix-fix.patch
thp-mremap-support-and-tlb-optimization-fix-fix-fix.patch
thp-tail-page-refcounting-fix-5.patch
powerpc-remove-superfluous-pagetail-checks-on-the-pte-gup_fast.patch
powerpc-get_hugepte-dont-put_page-the-wrong-page.patch
powerpc-gup_hugepte-avoid-to-free-the-head-page-too-many-times.patch
powerpc-gup_hugepte-support-thp-based-tail-recounting.patch
mm-mempolicyc-quiet-sparse-noise.patch
mm-huge_memoryc-quiet-sparse-noise.patch
vmscan-limit-direct-reclaim-for-higher-order-allocations.patch
vmscan-limit-direct-reclaim-for-higher-order-allocations-fix.patch
vmscan-abort-reclaim-compaction-if-compaction-can-proceed.patch
mm-huge_memory-fix-copying-user-highpage.patch
mm-huge_memory-fix-typo-when-updating-mmu-cache.patch
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