thp: pte alloc trans splitting
pte alloc routines must wait for split_huge_page if the pmd is not present
and not null (i.e. pmd_trans_splitting). The additional branches are
optimized away at compile time by pmd_trans_splitting if the config option
is off. However we must pass the vma down in order to know the anon_vma
lock to wait for.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c
index 93292a1..709244c 100644
--- a/arch/arm/mm/pgd.c
+++ b/arch/arm/mm/pgd.c
@@ -50,7 +50,7 @@
if (!new_pmd)
goto no_pmd;
- new_pte = pte_alloc_map(mm, new_pmd, 0);
+ new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
if (!new_pte)
goto no_pte;
diff --git a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c
index 1841ee7..5ca674b 100644
--- a/arch/ia64/mm/hugetlbpage.c
+++ b/arch/ia64/mm/hugetlbpage.c
@@ -38,7 +38,7 @@
if (pud) {
pmd = pmd_alloc(mm, pud, taddr);
if (pmd)
- pte = pte_alloc_map(mm, pmd, taddr);
+ pte = pte_alloc_map(mm, NULL, pmd, taddr);
}
return pte;
}
diff --git a/arch/sh/mm/hugetlbpage.c b/arch/sh/mm/hugetlbpage.c
index 9163db3..d776234 100644
--- a/arch/sh/mm/hugetlbpage.c
+++ b/arch/sh/mm/hugetlbpage.c
@@ -35,7 +35,7 @@
if (pud) {
pmd = pmd_alloc(mm, pud, addr);
if (pmd)
- pte = pte_alloc_map(mm, pmd, addr);
+ pte = pte_alloc_map(mm, NULL, pmd, addr);
}
}
diff --git a/arch/sparc/mm/generic_32.c b/arch/sparc/mm/generic_32.c
index 5edcac1..e6067b7 100644
--- a/arch/sparc/mm/generic_32.c
+++ b/arch/sparc/mm/generic_32.c
@@ -50,7 +50,7 @@
end = PGDIR_SIZE;
offset -= address;
do {
- pte_t * pte = pte_alloc_map(mm, pmd, address);
+ pte_t *pte = pte_alloc_map(mm, NULL, pmd, address);
if (!pte)
return -ENOMEM;
io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
diff --git a/arch/sparc/mm/generic_64.c b/arch/sparc/mm/generic_64.c
index 04f2bf4..3cb00df 100644
--- a/arch/sparc/mm/generic_64.c
+++ b/arch/sparc/mm/generic_64.c
@@ -92,7 +92,7 @@
end = PGDIR_SIZE;
offset -= address;
do {
- pte_t * pte = pte_alloc_map(mm, pmd, address);
+ pte_t *pte = pte_alloc_map(mm, NULL, pmd, address);
if (!pte)
return -ENOMEM;
io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index 5fdddf1..f4e9764 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -214,7 +214,7 @@
if (pud) {
pmd = pmd_alloc(mm, pud, addr);
if (pmd)
- pte = pte_alloc_map(mm, pmd, addr);
+ pte = pte_alloc_map(mm, NULL, pmd, addr);
}
return pte;
}
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 3d099f9..1aee587 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -31,7 +31,7 @@
if (!pmd)
goto out_pmd;
- pte = pte_alloc_map(mm, pmd, proc);
+ pte = pte_alloc_map(mm, NULL, pmd, proc);
if (!pte)
goto out_pte;
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index c2f1b26..998e972 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -133,7 +133,7 @@
pmd = pmd_alloc(&tboot_mm, pud, vaddr);
if (!pmd)
return -1;
- pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
+ pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr);
if (!pte)
return -1;
set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6bef67d..14ddd98 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1131,7 +1131,8 @@
int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
#endif
-int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
+int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long address);
int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
/*
@@ -1200,16 +1201,18 @@
pte_unmap(pte); \
} while (0)
-#define pte_alloc_map(mm, pmd, address) \
- ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
- NULL: pte_offset_map(pmd, address))
+#define pte_alloc_map(mm, vma, pmd, address) \
+ ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, vma, \
+ pmd, address))? \
+ NULL: pte_offset_map(pmd, address))
#define pte_alloc_map_lock(mm, pmd, address, ptlp) \
- ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
+ ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, NULL, \
+ pmd, address))? \
NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
#define pte_alloc_kernel(pmd, address) \
- ((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
+ ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
NULL: pte_offset_kernel(pmd, address))
extern void free_area_init(unsigned long * zones_size);
diff --git a/mm/memory.c b/mm/memory.c
index bdf1936..567bca8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -394,9 +394,11 @@
}
}
-int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
+int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long address)
{
pgtable_t new = pte_alloc_one(mm, address);
+ int wait_split_huge_page;
if (!new)
return -ENOMEM;
@@ -416,14 +418,18 @@
smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */
spin_lock(&mm->page_table_lock);
- if (!pmd_present(*pmd)) { /* Has another populated it ? */
+ wait_split_huge_page = 0;
+ if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
mm->nr_ptes++;
pmd_populate(mm, pmd, new);
new = NULL;
- }
+ } else if (unlikely(pmd_trans_splitting(*pmd)))
+ wait_split_huge_page = 1;
spin_unlock(&mm->page_table_lock);
if (new)
pte_free(mm, new);
+ if (wait_split_huge_page)
+ wait_split_huge_page(vma->anon_vma, pmd);
return 0;
}
@@ -436,10 +442,11 @@
smp_wmb(); /* See comment in __pte_alloc */
spin_lock(&init_mm.page_table_lock);
- if (!pmd_present(*pmd)) { /* Has another populated it ? */
+ if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
pmd_populate_kernel(&init_mm, pmd, new);
new = NULL;
- }
+ } else
+ VM_BUG_ON(pmd_trans_splitting(*pmd));
spin_unlock(&init_mm.page_table_lock);
if (new)
pte_free_kernel(&init_mm, new);
@@ -3253,7 +3260,7 @@
pmd = pmd_alloc(mm, pud, address);
if (!pmd)
return VM_FAULT_OOM;
- pte = pte_alloc_map(mm, pmd, address);
+ pte = pte_alloc_map(mm, vma, pmd, address);
if (!pte)
return VM_FAULT_OOM;
diff --git a/mm/mremap.c b/mm/mremap.c
index 563fbdd..b09eefa 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -47,7 +47,8 @@
return pmd;
}
-static pmd_t *alloc_new_pmd(struct mm_struct *mm, unsigned long addr)
+static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
@@ -62,7 +63,8 @@
if (!pmd)
return NULL;
- if (!pmd_present(*pmd) && __pte_alloc(mm, pmd, addr))
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+ if (pmd_none(*pmd) && __pte_alloc(mm, vma, pmd, addr))
return NULL;
return pmd;
@@ -147,7 +149,7 @@
old_pmd = get_old_pmd(vma->vm_mm, old_addr);
if (!old_pmd)
continue;
- new_pmd = alloc_new_pmd(vma->vm_mm, new_addr);
+ new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr);
if (!new_pmd)
break;
next = (new_addr + PMD_SIZE) & PMD_MASK;
