This patch extends check_range() to handle vma with VM_HUGETLB set.
We will be able to migrate hugepage with migrate_pages(2) after
applying the enablement patch which comes later in this series.
Note that for larger hugepages (covered by pud entries, 1GB for
x86_64 for example), we simply skip it now.
Note that using pmd_huge/pud_huge assumes that hugepages are pointed to
by pmd/pud. This is not true in some architectures implementing hugepage
with other mechanisms like ia64, but it's OK because pmd_huge/pud_huge
simply return 0 in such arch and page walker simply ignores such hugepages.
ChangeLog v3:
- revert introducing migrate_movable_pages
- use isolate_huge_page
ChangeLog v2:
- remove unnecessary extern
- fix page table lock in check_hugetlb_pmd_range
- updated description and renamed patch title
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
mm/mempolicy.c | 39 ++++++++++++++++++++++++++++++++++-----
1 file changed, 34 insertions(+), 5 deletions(-)
diff --git v3.11-rc1.orig/mm/mempolicy.c v3.11-rc1/mm/mempolicy.c
index 7431001..f3b65c0 100644
--- v3.11-rc1.orig/mm/mempolicy.c
+++ v3.11-rc1/mm/mempolicy.c
@@ -512,6 +512,27 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
return addr != end;
}
+static void check_hugetlb_pmd_range(struct vm_area_struct *vma, pmd_t *pmd,
+ const nodemask_t *nodes, unsigned long flags,
+ void *private)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+ int nid;
+ struct page *page;
+
+ spin_lock(&vma->vm_mm->page_table_lock);
+ page = pte_page(huge_ptep_get((pte_t *)pmd));
+ nid = page_to_nid(page);
+ if (node_isset(nid, *nodes) != !!(flags & MPOL_MF_INVERT)
+ && ((flags & MPOL_MF_MOVE && page_mapcount(page) == 1)
+ || flags & MPOL_MF_MOVE_ALL))
+ isolate_huge_page(page, private);
+ spin_unlock(&vma->vm_mm->page_table_lock);
+#else
+ BUG();
+#endif
+}
+
static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
@@ -523,6 +544,11 @@ static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
+ if (pmd_huge(*pmd) && is_vm_hugetlb_page(vma)) {
+ check_hugetlb_pmd_range(vma, pmd, nodes,
+ flags, private);
+ continue;
+ }
split_huge_page_pmd(vma, addr, pmd);
if (pmd_none_or_trans_huge_or_clear_bad(pmd))
continue;
@@ -544,6 +570,8 @@ static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
+ if (pud_huge(*pud) && is_vm_hugetlb_page(vma))
+ continue;
if (pud_none_or_clear_bad(pud))
continue;
if (check_pmd_range(vma, pud, addr, next, nodes,
@@ -635,9 +663,6 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
return ERR_PTR(-EFAULT);
}
- if (is_vm_hugetlb_page(vma))
- goto next;
-
if (flags & MPOL_MF_LAZY) {
change_prot_numa(vma, start, endvma);
goto next;
@@ -986,7 +1011,11 @@ static void migrate_page_add(struct page *page, struct list_head *pagelist,
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
{
- return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
+ if (PageHuge(page))
+ return alloc_huge_page_node(page_hstate(compound_head(page)),
+ node);
+ else
+ return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
}
/*
@@ -1016,7 +1045,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
err = migrate_pages(&pagelist, new_node_page, dest,
MIGRATE_SYNC, MR_SYSCALL);
if (err)
- putback_lru_pages(&pagelist);
+ putback_movable_pages(&pagelist);
}
return err;
--
1.8.3.1
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