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-rw-r--r--mm/memory_hotplug.c11
-rw-r--r--mm/page_alloc.c2
-rw-r--r--mm/page_isolation.c10
3 files changed, 13 insertions, 10 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 41c62295292b..3c494ab0d075 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1500,6 +1500,8 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
goto failed_removal;
}
+ drain_all_pages(zone);
+
arg.start_pfn = start_pfn;
arg.nr_pages = nr_pages;
node_states_check_changes_offline(nr_pages, zone, &arg);
@@ -1550,11 +1552,10 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
}
/*
- * per-cpu pages are drained in start_isolate_page_range, but if
- * there are still pages that are not free, make sure that we
- * drain again, because when we isolated range we might
- * have raced with another thread that was adding pages to pcp
- * list.
+ * per-cpu pages are drained after start_isolate_page_range, but
+ * if there are still pages that are not free, make sure that we
+ * drain again, because when we isolated range we might have
+ * raced with another thread that was adding pages to pcp list.
*
* Forward progress should be still guaranteed because
* pages on the pcp list can only belong to MOVABLE_ZONE
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3d1752b57dc..a259c22e4609 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8528,6 +8528,8 @@ int alloc_contig_range(unsigned long start, unsigned long end,
if (ret)
return ret;
+ drain_all_pages(cc.zone);
+
/*
* In case of -EBUSY, we'd like to know which page causes problem.
* So, just fall through. test_pages_isolated() has a tracepoint
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index abbf42214485..feab446d1982 100644
--- 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.
*/