If zswap_store() successfully stores an mTHP, it will be
counted under the per-order sysfs "zswpout" stats:
/sys/kernel/mm/transparent_hugepage/hugepages-*kB/stats/zswpout
Other block dev/fs mTHP swap-out events will be counted under
the existing sysfs "swpout" stats:
/sys/kernel/mm/transparent_hugepage/hugepages-*kB/stats/swpout
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
---
mm/page_io.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/mm/page_io.c b/mm/page_io.c
index ff8c99ee3af7..debd04fbdfd0 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -172,6 +172,12 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
goto out;
}
+static inline void count_mthp_zswpout_vm_event(struct folio *folio)
+{
+ if (IS_ENABLED(CONFIG_THP_SWAP))
+ count_mthp_stat(folio_order(folio), MTHP_STAT_ZSWPOUT);
+}
+
/*
* We may have stale swap cache pages in memory: notice
* them here and get rid of the unnecessary final write.
@@ -196,6 +202,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
return ret;
}
if (zswap_store(folio)) {
+ count_mthp_zswpout_vm_event(folio);
folio_unlock(folio);
return 0;
}
--
2.27.0
