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-rw-r--r--mm/memory-failure.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 9349948f1abf..9e62a00b46dd 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -154,11 +154,23 @@ static int __page_handle_poison(struct page *page)
{
int ret;
- zone_pcp_disable(page_zone(page));
+ /*
+ * zone_pcp_disable() can't be used here. It will
+ * hold pcp_batch_high_lock and dissolve_free_huge_page() might hold
+ * cpu_hotplug_lock via static_key_slow_dec() when hugetlb vmemmap
+ * optimization is enabled. This will break current lock dependency
+ * chain and leads to deadlock.
+ * Disabling pcp before dissolving the page was a deterministic
+ * approach because we made sure that those pages cannot end up in any
+ * PCP list. Draining PCP lists expels those pages to the buddy system,
+ * but nothing guarantees that those pages do not get back to a PCP
+ * queue if we need to refill those.
+ */
ret = dissolve_free_huge_page(page);
- if (!ret)
+ if (!ret) {
+ drain_all_pages(page_zone(page));
ret = take_page_off_buddy(page);
- zone_pcp_enable(page_zone(page));
+ }
return ret;
}