mm: drop the 'anon_' prefix for swap-out mTHP counters

The mTHP swap related counters: 'anon_swpout' and 'anon_swpout_fallback'
are confusing with an 'anon_' prefix, since the shmem can swap out
non-anonymous pages.  So drop the 'anon_' prefix to keep consistent with
the old swap counter names.

This is needed in 6.10-rcX to avoid having an inconsistent ABI out in the
field.

Link: https://lkml.kernel.org/r/7a8989c13299920d7589007a30065c3e2c19f0e0.1716431702.git.baolin.wang@linux.alibaba.com
Fixes: d0f048a ("mm: add per-order mTHP anon_swpout and anon_swpout_fallback counters")
Fixes: 42248b9 ("mm: add docs for per-order mTHP counters and transhuge_page ABI")
Signed-off-by: Baolin Wang <[email protected]>
Suggested-by: "Huang, Ying" <[email protected]>
Acked-by: Barry Song <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Baolin Wang

Documentation/admin-guide/mm/transhuge.rst

@@ -467,11 +467,11 @@ anon_fault_fallback_charge
 	instead falls back to using huge pages with lower orders or
 	small pages even though the allocation was successful.
 
-anon_swpout
+swpout
 	is incremented every time a huge page is swapped out in one
 	piece without splitting.
 
-anon_swpout_fallback
+swpout_fallback
 	is incremented if a huge page has to be split before swapout.
 	Usually because failed to allocate some continuous swap space
 	for the huge page.

include/linux/huge_mm.h

@@ -269,8 +269,8 @@ enum mthp_stat_item {
 	MTHP_STAT_ANON_FAULT_ALLOC,
 	MTHP_STAT_ANON_FAULT_FALLBACK,
 	MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
-	MTHP_STAT_ANON_SWPOUT,
-	MTHP_STAT_ANON_SWPOUT_FALLBACK,
+	MTHP_STAT_SWPOUT,
+	MTHP_STAT_SWPOUT_FALLBACK,
 	__MTHP_STAT_COUNT
 };
 

mm/huge_memory.c

@@ -558,15 +558,15 @@ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 DEFINE_MTHP_STAT_ATTR(anon_fault_alloc, MTHP_STAT_ANON_FAULT_ALLOC);
 DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_STAT_ANON_FAULT_FALLBACK);
 DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE);
-DEFINE_MTHP_STAT_ATTR(anon_swpout, MTHP_STAT_ANON_SWPOUT);
-DEFINE_MTHP_STAT_ATTR(anon_swpout_fallback, MTHP_STAT_ANON_SWPOUT_FALLBACK);
+DEFINE_MTHP_STAT_ATTR(swpout, MTHP_STAT_SWPOUT);
+DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK);
 
 static struct attribute *stats_attrs[] = {
 	&anon_fault_alloc_attr.attr,
 	&anon_fault_fallback_attr.attr,
 	&anon_fault_fallback_charge_attr.attr,
-	&anon_swpout_attr.attr,
-	&anon_swpout_fallback_attr.attr,
+	&swpout_attr.attr,
+	&swpout_fallback_attr.attr,
 	NULL,
 };
 

mm/page_io.c

@@ -217,7 +217,7 @@ static inline void count_swpout_vm_event(struct folio *folio)
 		count_memcg_folio_events(folio, THP_SWPOUT, 1);
 		count_vm_event(THP_SWPOUT);
 	}
-	count_mthp_stat(folio_order(folio), MTHP_STAT_ANON_SWPOUT);
+	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
 #endif
 	count_vm_events(PSWPOUT, folio_nr_pages(folio));
 }

mm/vmscan.c

@@ -1227,7 +1227,7 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
 							THP_SWPOUT_FALLBACK, 1);
 						count_vm_event(THP_SWPOUT_FALLBACK);
 					}
-					count_mthp_stat(order, MTHP_STAT_ANON_SWPOUT_FALLBACK);
+					count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
 #endif
 					if (!add_to_swap(folio))
 						goto activate_locked_split;