mm/mempolicy: rename check_*range to queue_pages_*range

The function check_range() (and its family) is not well-named, because it
does not only checking something, but moving pages from list to list to do
page migration for them.  So queue_pages_*range is more desirable name.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c

@@ -476,8 +476,11 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
 static void migrate_page_add(struct page *page, struct list_head *pagelist,
 				unsigned long flags);
 
-/* Scan through pages checking if pages follow certain conditions. */
-static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+/*
+ * Scan through pages checking if pages follow certain conditions,
+ * and move them to the pagelist if they do.
+ */
+static int queue_pages_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 		unsigned long addr, unsigned long end,
 		const nodemask_t *nodes, unsigned long flags,
 		void *private)
@@ -515,8 +518,8 @@ 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,
+static void queue_pages_hugetlb_pmd_range(struct vm_area_struct *vma,
+		pmd_t *pmd, const nodemask_t *nodes, unsigned long flags,
 				    void *private)
 {
 #ifdef CONFIG_HUGETLB_PAGE
@@ -539,7 +542,7 @@ unlock:
 #endif
 }
 
-static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+static inline int queue_pages_pmd_range(struct vm_area_struct *vma, pud_t *pud,
 		unsigned long addr, unsigned long end,
 		const nodemask_t *nodes, unsigned long flags,
 		void *private)
@@ -553,21 +556,21 @@ static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
 		if (!pmd_present(*pmd))
 			continue;
 		if (pmd_huge(*pmd) && is_vm_hugetlb_page(vma)) {
-			check_hugetlb_pmd_range(vma, pmd, nodes,
+			queue_pages_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;
-		if (check_pte_range(vma, pmd, addr, next, nodes,
+		if (queue_pages_pte_range(vma, pmd, addr, next, nodes,
 				    flags, private))
 			return -EIO;
 	} while (pmd++, addr = next, addr != end);
 	return 0;
 }
 
-static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+static inline int queue_pages_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
 		unsigned long addr, unsigned long end,
 		const nodemask_t *nodes, unsigned long flags,
 		void *private)
@@ -582,14 +585,14 @@ static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
 			continue;
 		if (pud_none_or_clear_bad(pud))
 			continue;
-		if (check_pmd_range(vma, pud, addr, next, nodes,
+		if (queue_pages_pmd_range(vma, pud, addr, next, nodes,
 				    flags, private))
 			return -EIO;
 	} while (pud++, addr = next, addr != end);
 	return 0;
 }
 
-static inline int check_pgd_range(struct vm_area_struct *vma,
+static inline int queue_pages_pgd_range(struct vm_area_struct *vma,
 		unsigned long addr, unsigned long end,
 		const nodemask_t *nodes, unsigned long flags,
 		void *private)
@@ -602,7 +605,7 @@ static inline int check_pgd_range(struct vm_area_struct *vma,
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
-		if (check_pud_range(vma, pgd, addr, next, nodes,
+		if (queue_pages_pud_range(vma, pgd, addr, next, nodes,
 				    flags, private))
 			return -EIO;
 	} while (pgd++, addr = next, addr != end);
@@ -640,12 +643,14 @@ static unsigned long change_prot_numa(struct vm_area_struct *vma,
 #endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */
 
 /*
- * Check if all pages in a range are on a set of nodes.
- * If pagelist != NULL then isolate pages from the LRU and
- * put them on the pagelist.
+ * Walk through page tables and collect pages to be migrated.
+ *
+ * If pages found in a given range are on a set of nodes (determined by
+ * @nodes and @flags,) it's isolated and queued to the pagelist which is
+ * passed via @private.)
  */
 static struct vm_area_struct *
-check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
+queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 		const nodemask_t *nodes, unsigned long flags, void *private)
 {
 	int err;
@@ -680,7 +685,7 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 		     ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
 		      vma_migratable(vma))) {
 
-			err = check_pgd_range(vma, start, endvma, nodes,
+			err = queue_pages_pgd_range(vma, start, endvma, nodes,
 						flags, private);
 			if (err) {
 				first = ERR_PTR(err);
@@ -1050,7 +1055,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
 	 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
 	 */
 	VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
-	check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
+	queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
 			flags | MPOL_MF_DISCONTIG_OK, &pagelist);
 
 	if (!list_empty(&pagelist)) {
@@ -1288,7 +1293,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 	if (err)
 		goto mpol_out;
 
-	vma = check_range(mm, start, end, nmask,
+	vma = queue_pages_range(mm, start, end, nmask,
 			  flags | MPOL_MF_INVERT, &pagelist);
 
 	err = PTR_ERR(vma);	/* maybe ... */