On 7/16/19 1:47 AM, Vlastimil Babka wrote:
On 7/16/19 10:12 AM, Vlastimil Babka wrote:
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -429,11 +429,14 @@ static inline bool queue_pages_required(struct page *page,
}
/*
- * queue_pages_pmd() has three possible return values:
+ * queue_pages_pmd() has four possible return values:
+ * 2 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
+ * specified.
* 1 - pages are placed on the right node or queued successfully.
* 0 - THP was split.
I think if you renumbered these, it would be more consistent with
queue_pages_pte_range() and simplify the code there.
0 - pages on right node/queued
1 - unmovable page with right flags specified
2 - THP split
Ah, alternatively you could add a boolean to struct queue_pages
accessible from mm_walk, set true to indicate that unmovable page has
been encountered, without propagating it back through special return values.
I will try both to see which one (renumbering return value or use flag)
is better.
Thanks,
Yang
