memory_failure() chooses a recovery action function based on the page flags. For huge pages it uses the tail page flags which don't have anything interesting set, resulting in: > Memory failure: 0x9be3b4: Unknown page state > Memory failure: 0x9be3b4: recovery action for unknown page: Failed Instead, save a copy of the head page's flags if this is a huge page, this means if there are no relevant flags for this tail page, we use the head pages flags instead. This results in the me_huge_page() recovery action being called: > Memory failure: 0x9b7969: recovery action for huge page: Delayed For hugepages that have not yet been allocated, this allows the hugepage to be dequeued. CC: Punit Agrawal <punit.agrawal@xxxxxxx> Signed-off-by: James Morse <james.morse@xxxxxxx> --- This is intended as a fix, but I can't find the patch that introduced this behaviour. (not recent, and there is a lot of history down there!) This doesn't apply to stable trees before v3.10... Cc: stable@xxxxxxxxxxxxxxx # 3.10.105 mm/memory-failure.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2527dfeddb00..44a6a33af219 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1184,7 +1184,10 @@ int memory_failure(unsigned long pfn, int trapno, int flags) * page_remove_rmap() in try_to_unmap_one(). So to determine page status * correctly, we save a copy of the page flags at this time. */ - page_flags = p->flags; + if (PageHuge(p)) + page_flags = hpage->flags; + else + page_flags = p->flags; /* * unpoison always clear PG_hwpoison inside page lock -- 2.11.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
