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 v4:
- refactored check_hugetlb_pmd_range for better readability
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-horigu...@ah.jp.nec.com>
Acked-by: Andi Kleen <a...@linux.intel.com>
Reviewed-by: Wanpeng Li <liw...@linux.vnet.ibm.com>
Acked-by: Hillf Danton <dhi...@gmail.com>
---
mm/mempolicy.c | 42 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 37 insertions(+), 5 deletions(-)
diff --git v3.11-rc3.orig/mm/mempolicy.c v3.11-rc3/mm/mempolicy.c
index 7431001..d96afc1 100644
--- v3.11-rc3.orig/mm/mempolicy.c
+++ v3.11-rc3/mm/mempolicy.c
@@ -512,6 +512,30 @@ 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))
+ goto unlock;
+ /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
+ if (flags & (MPOL_MF_MOVE_ALL) ||
+ (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
+ isolate_huge_page(page, private);
+unlock:
+ 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 +547,11 @@ 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 +573,8 @@ 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 +666,6 @@ 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 +1014,11 @@ 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 +1048,7 @@ 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
