From: Zi Yan <ziy@xxxxxxxxxx>
It allows removing huge pmd while holding the pmd lock.
It is prepared for future zap_pmd_range() use.
Signed-off-by: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
---
include/linux/huge_mm.h | 3 +++
mm/huge_memory.c | 27 ++++++++++++++++++---------
2 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 2036f69c8284..44ee130c7207 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -26,6 +26,9 @@ extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
extern bool madvise_free_huge_pmd(struct mmu_gather *tlb,
struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr, unsigned long next);
+extern int __zap_huge_pmd_locked(struct mmu_gather *tlb,
+ struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long addr);
extern int zap_huge_pmd(struct mmu_gather *tlb,
struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index cd66532ef667..d8e15fd817b0 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1590,17 +1590,12 @@ static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd)
atomic_long_dec(&mm->nr_ptes);
}
-int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
+int __zap_huge_pmd_locked(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
pmd_t orig_pmd;
- spinlock_t *ptl;
tlb_remove_check_page_size_change(tlb, HPAGE_PMD_SIZE);
-
- ptl = __pmd_trans_huge_lock(pmd, vma);
- if (!ptl)
- return 0;
/*
* For architectures like ppc64 we look at deposited pgtable
* when calling pmdp_huge_get_and_clear. So do the
@@ -1611,13 +1606,11 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
tlb->fullmm);
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
if (vma_is_dax(vma)) {
- spin_unlock(ptl);
if (is_huge_zero_pmd(orig_pmd))
tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE);
} else if (is_huge_zero_pmd(orig_pmd)) {
pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(ptl);
tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE);
} else {
struct page *page = pmd_page(orig_pmd);
@@ -1635,9 +1628,25 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
zap_deposited_table(tlb->mm, pmd);
add_mm_counter(tlb->mm, MM_FILEPAGES, -HPAGE_PMD_NR);
}
- spin_unlock(ptl);
tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE);
}
+
+ return 1;
+}
+
+int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long addr)
+{
+ spinlock_t *ptl;
+
+
+ ptl = __pmd_trans_huge_lock(pmd, vma);
+ if (!ptl)
+ return 0;
+
+ __zap_huge_pmd_locked(tlb, vma, pmd, addr);
+
+ spin_unlock(ptl);
return 1;
}
--
2.11.0
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