mm,hwpoison: introduce MF_MSG_UNSPLIT_THP

memory_failure() is supposed to call action_result() when it handles a
memory error event, but there's one missing case.  So let's add it.

I find that include/ras/ras_event.h has some other MF_MSG_* undefined, so
this patch also adds them.

Signed-off-by: Naoya Horiguchi <[email protected]>
Signed-off-by: Oscar Salvador <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Aristeu Rozanski <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Dmitry Yakunin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Qian Cai <[email protected]>
Cc: Tony Luck <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

Author: nhoriguchi

include/linux/mm.h

@@ -3064,6 +3064,7 @@ enum mf_action_page_type {
 	MF_MSG_BUDDY,
 	MF_MSG_BUDDY_2ND,
 	MF_MSG_DAX,
+	MF_MSG_UNSPLIT_THP,
 	MF_MSG_UNKNOWN,
 };
 

include/ras/ras_event.h

@@ -361,6 +361,7 @@ TRACE_EVENT(aer_event,
 	EM ( MF_MSG_POISONED_HUGE, "huge page already hardware poisoned" )	\
 	EM ( MF_MSG_HUGE, "huge page" )					\
 	EM ( MF_MSG_FREE_HUGE, "free huge page" )			\
+	EM ( MF_MSG_NON_PMD_HUGE, "non-pmd-sized huge page" )		\
 	EM ( MF_MSG_UNMAP_FAILED, "unmapping failed page" )		\
 	EM ( MF_MSG_DIRTY_SWAPCACHE, "dirty swapcache page" )		\
 	EM ( MF_MSG_CLEAN_SWAPCACHE, "clean swapcache page" )		\
@@ -373,6 +374,8 @@ TRACE_EVENT(aer_event,
 	EM ( MF_MSG_TRUNCATED_LRU, "already truncated LRU page" )	\
 	EM ( MF_MSG_BUDDY, "free buddy page" )				\
 	EM ( MF_MSG_BUDDY_2ND, "free buddy page (2nd try)" )		\
+	EM ( MF_MSG_DAX, "dax page" )					\
+	EM ( MF_MSG_UNSPLIT_THP, "unsplit thp" )			\
 	EMe ( MF_MSG_UNKNOWN, "unknown page" )
 
 /*

mm/memory-failure.c

@@ -582,6 +582,7 @@ static const char * const action_page_types[] = {
 	[MF_MSG_BUDDY]			= "free buddy page",
 	[MF_MSG_BUDDY_2ND]		= "free buddy page (2nd try)",
 	[MF_MSG_DAX]			= "dax page",
+	[MF_MSG_UNSPLIT_THP]		= "unsplit thp",
 	[MF_MSG_UNKNOWN]		= "unknown page",
 };
 
@@ -1370,8 +1371,10 @@ int memory_failure(unsigned long pfn, int flags)
 	}
 
 	if (PageTransHuge(hpage)) {
-		if (try_to_split_thp_page(p, "Memory Failure") < 0)
+		if (try_to_split_thp_page(p, "Memory Failure") < 0) {
+			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
 			return -EBUSY;
+		}
 		VM_BUG_ON_PAGE(!page_count(p), p);
 	}