The patch titled
Subject: mm: swap: Count successful large folio zswap stores in hugepage zswpout stats.
has been added to the -mm mm-unstable branch. Its filename is
mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
Subject: mm: swap: Count successful large folio zswap stores in hugepage zswpout stats.
Date: Mon, 30 Sep 2024 22:32:22 -0700
Added a new MTHP_STAT_ZSWPOUT entry to the sysfs transparent_hugepage
stats so that successful large folio zswap stores can be accounted under
the per-order sysfs "zswpout" stats:
/sys/kernel/mm/transparent_hugepage/hugepages-*kB/stats/zswpout
Other non-zswap swap device swap-out events will be counted under
the existing sysfs "swpout" stats:
/sys/kernel/mm/transparent_hugepage/hugepages-*kB/stats/swpout
Also, added documentation for the newly added sysfs per-order hugepage
"zswpout" stats. The documentation clarifies that only non-zswap swapouts
will be accounted in the existing "swpout" stats.
Link: https://lkml.kernel.org/r/20241001053222.6944-8-kanchana.p.sridhar@xxxxxxxxx
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
Reviewed-by: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Chengming Zhou <chengming.zhou@xxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Usama Arif <usamaarif642@xxxxxxxxx>
Cc: Wajdi Feghali <wajdi.k.feghali@xxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Cc: "Zou, Nanhai" <nanhai.zou@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/mm/transhuge.rst | 8 ++++++--
include/linux/huge_mm.h | 1 +
mm/huge_memory.c | 3 +++
mm/page_io.c | 1 +
4 files changed, 11 insertions(+), 2 deletions(-)
--- a/Documentation/admin-guide/mm/transhuge.rst~mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats
+++ a/Documentation/admin-guide/mm/transhuge.rst
@@ -530,10 +530,14 @@ anon_fault_fallback_charge
instead falls back to using huge pages with lower orders or
small pages even though the allocation was successful.
-swpout
- is incremented every time a huge page is swapped out in one
+zswpout
+ is incremented every time a huge page is swapped out to zswap in one
piece without splitting.
+swpout
+ is incremented every time a huge page is swapped out to a non-zswap
+ swap device in one piece without splitting.
+
swpout_fallback
is incremented if a huge page has to be split before swapout.
Usually because failed to allocate some continuous swap space
--- a/include/linux/huge_mm.h~mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats
+++ a/include/linux/huge_mm.h
@@ -119,6 +119,7 @@ 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,
--- a/mm/huge_memory.c~mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats
+++ a/mm/huge_memory.c
@@ -611,6 +611,7 @@ static struct kobj_attribute _name##_att
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);
#ifdef CONFIG_SHMEM
@@ -629,6 +630,7 @@ static struct attribute *anon_stats_attr
&anon_fault_fallback_attr.attr,
&anon_fault_fallback_charge_attr.attr,
#ifndef CONFIG_SHMEM
+ &zswpout_attr.attr,
&swpout_attr.attr,
&swpout_fallback_attr.attr,
#endif
@@ -659,6 +661,7 @@ static struct attribute_group file_stats
static struct attribute *any_stats_attrs[] = {
#ifdef CONFIG_SHMEM
+ &zswpout_attr.attr,
&swpout_attr.attr,
&swpout_fallback_attr.attr,
#endif
--- a/mm/page_io.c~mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats
+++ a/mm/page_io.c
@@ -269,6 +269,7 @@ int swap_writepage(struct page *page, st
swap_zeromap_folio_clear(folio);
}
if (zswap_store(folio)) {
+ count_mthp_stat(folio_order(folio), MTHP_STAT_ZSWPOUT);
folio_unlock(folio);
return 0;
}
_
Patches currently in -mm which might be from kanchana.p.sridhar@xxxxxxxxx are
mm-define-obj_cgroup_get-if-config_memcg-is-not-defined.patch
mm-zswap-modify-zswap_compress-to-accept-a-page-instead-of-a-folio.patch
mm-zswap-rename-zswap_pool_get-to-zswap_pool_tryget.patch
mm-change-count_objcg_event-to-count_objcg_events-for-batch-event-updates.patch
mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t.patch
mm-zswap-support-large-folios-in-zswap_store.patch
mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats.patch
