From: James Morse <james.morse@xxxxxxx>
Subject: mm/memory-failure.c: use compound_head() flags for huge pages
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.
Fixes: 524fca1e7356 ("HWPOISON: fix misjudgement of page_action() for errors on mlocked pages")
Link: http://lkml.kernel.org/r/20170524130204.21845-1-james.morse@xxxxxxx
Signed-off-by: James Morse <james.morse@xxxxxxx>
Tested-by: Punit Agrawal <punit.agrawal@xxxxxxx>
Acked-by: Punit Agrawal <punit.agrawal@xxxxxxx>
Acked-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff -puN mm/memory-failure.c~mm-hwpoison-use-compound_head-flags-for-huge-pages mm/memory-failure.c
--- a/mm/memory-failure.c~mm-hwpoison-use-compound_head-flags-for-huge-pages
+++ a/mm/memory-failure.c
@@ -1184,7 +1184,10 @@ int memory_failure(unsigned long pfn, in
* 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
_