[PATCH] mm: enhance comment and bug check

[Minchan Kim]

This patch updates comment and bug check.
It can be fold into [1].

[1] mm-revert-0def08e3-mm-mempolicyc-check-return-code-of-check_range.patch

Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
 mm/mempolicy.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 9ec87bd..0b78fb9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -951,9 +951,11 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
 	node_set(source, nmask);
 
 	/*
-	 * Collect migrate pages and it shoudn't be failed.
+	 * This does not "check" the range but isolates all pages that
+	 * need migration.  Between passing in the full user address
+	 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
 	 */
-	VM_BUG_ON(flags & MPOL_MF_STRICT);
+	VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
 	check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
 			flags | MPOL_MF_DISCONTIG_OK, &pagelist);
 
-- 
1.7.9.5

-- 
Kind regards,
Minchan Kim
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/