mm, page_alloc: move draining pcplists to page isolation users

[mirror_ubuntu-jammy-kernel.git] / mm / page_isolation.c

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index abbf422144850977dfba2f657c63330e5d2da217..feab446d198282f81f086a746f70320a6f411141 100644 (file)
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -49,7 +49,6 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_
 
                __mod_zone_freepage_state(zone, -nr_pages, mt);
                spin_unlock_irqrestore(&zone->lock, flags);
-               drain_all_pages(zone);
                return 0;
        }
 
@@ -172,11 +171,12 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages)
  *
  * Please note that there is no strong synchronization with the page allocator
  * either. Pages might be freed while their page blocks are marked ISOLATED.
- * In some cases pages might still end up on pcp lists and that would allow
+ * A call to drain_all_pages() after isolation can flush most of them. However
+ * in some cases pages might still end up on pcp lists and that would allow
  * for their allocation even when they are in fact isolated already. Depending
- * on how strong of a guarantee the caller needs drain_all_pages might be needed
- * (e.g. __offline_pages will need to call it after check for isolated range for
- * a next retry).
+ * on how strong of a guarantee the caller needs, further drain_all_pages()
+ * might be needed (e.g. __offline_pages will need to call it after check for
+ * isolated range for a next retry).
  *
  * Return: 0 on success and -EBUSY if any part of range cannot be isolated.
  */