mm/mempolicy: use readable NUMA_NO_NODE macro instead of magic number

The caller of mpol_misplaced() already use NUMA_NO_NODE to check whether
current page node is misplaced, thus using NUMA_NO_NODE in
mpol_misplaced() instead of magic number is more readable.

Link: https://lkml.kernel.org/r/1b77c0ce21183fa86f4db250b115cf5e27396528.1627558356.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index e675bfb..c473d29 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2425,8 +2425,8 @@ static void sp_free(struct sp_node *n)
  * node id.  Policy determination "mimics" alloc_page_vma().
  * Called from fault path where we know the vma and faulting address.
  *
- * Return: -1 if the page is in a node that is valid for this policy, or a
- * suitable node ID to allocate a replacement page from.
+ * Return: NUMA_NO_NODE if the page is in a node that is valid for this
+ * policy, or a suitable node ID to allocate a replacement page from.
  */
 int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
 {
@@ -2437,7 +2437,7 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
        int thiscpu = raw_smp_processor_id();
        int thisnid = cpu_to_node(thiscpu);
        int polnid = NUMA_NO_NODE;
-       int ret = -1;
+       int ret = NUMA_NO_NODE;
 
        pol = get_vma_policy(vma, addr);
        if (!(pol->flags & MPOL_F_MOF))