mm: mempolicy: Implement change_prot_numa() in terms of change_protection()
This patch converts change_prot_numa() to use change_protection(). As
pte_numa and friends check the PTE bits directly it is necessary for
change_protection() to use pmd_mknuma(). Hence the required
modifications to change_protection() are a little clumsy but the
end result is that most of the numa page table helpers are just one or
two instructions.
Signed-off-by: Mel Gorman <mgorman@suse.de>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 5723b55..d79f7a55 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1147,7 +1147,7 @@
}
int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
- unsigned long addr, pgprot_t newprot)
+ unsigned long addr, pgprot_t newprot, int prot_numa)
{
struct mm_struct *mm = vma->vm_mm;
int ret = 0;
@@ -1155,7 +1155,17 @@
if (__pmd_trans_huge_lock(pmd, vma) == 1) {
pmd_t entry;
entry = pmdp_get_and_clear(mm, addr, pmd);
- entry = pmd_modify(entry, newprot);
+ if (!prot_numa)
+ entry = pmd_modify(entry, newprot);
+ else {
+ struct page *page = pmd_page(*pmd);
+
+ /* only check non-shared pages */
+ if (page_mapcount(page) == 1 &&
+ !pmd_numa(*pmd)) {
+ entry = pmd_mknuma(entry);
+ }
+ }
set_pmd_at(mm, addr, pmd, entry);
spin_unlock(&vma->vm_mm->page_table_lock);
ret = 1;