[PATCH v2 3/4] mm: Add MTHP_STAT_ZSWPOUT to sysfs per-order mthp stats.

[Kanchana P Sridhar <kanchana.p.sridhar@intel.com>]

Add a new MTHP_STAT_ZSWPOUT entry to the sysfs mTHP stats so that
per-order mTHP folio ZSWAP stores can be accounted.

Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
---
 include/linux/huge_mm.h | 1 +
 mm/huge_memory.c        | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index e25d9ebfdf89..44609d84f2dd 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -273,6 +273,7 @@ enum mthp_stat_item {
 	MTHP_STAT_ANON_FAULT_ALLOC,
 	MTHP_STAT_ANON_FAULT_FALLBACK,
 	MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
+	MTHP_STAT_ZSWPOUT,
 	MTHP_STAT_SWPOUT,
 	MTHP_STAT_SWPOUT_FALLBACK,
 	MTHP_STAT_SHMEM_ALLOC,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f4be468e06a4..7e97b6ed6ff1 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -574,6 +574,7 @@ 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(zswpout, MTHP_STAT_ZSWPOUT);
 DEFINE_MTHP_STAT_ATTR(swpout, MTHP_STAT_SWPOUT);
 DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK);
 DEFINE_MTHP_STAT_ATTR(shmem_alloc, MTHP_STAT_SHMEM_ALLOC);
@@ -587,6 +588,7 @@ static struct attribute *stats_attrs[] = {
 	&anon_fault_alloc_attr.attr,
 	&anon_fault_fallback_attr.attr,
 	&anon_fault_fallback_charge_attr.attr,
+	&zswpout_attr.attr,
 	&swpout_attr.attr,
 	&swpout_fallback_attr.attr,
 	&shmem_alloc_attr.attr,
-- 
2.27.0