+ mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic.patch added to mm-unstable branch

+ mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: swap: make some count_mthp_stat() call-sites be THP-agnostic.
has been added to the -mm mm-unstable branch.  Its filename is
     mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic.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@intel.com>
Subject: mm: swap: make some count_mthp_stat() call-sites be THP-agnostic.
Date: Wed, 2 Oct 2024 15:58:22 -0700

In commit 246d3aa3e531 ("mm: cleanup count_mthp_stat() definition"), Ryan
Roberts has pointed out the merits of mm code that does not require THP,
to be compile-able without requiring THP ifdefs.  As a step in that
direction, he has moved count_mthp_stat() to be always defined, resolving
to a no-op if THP is not defined.

Barry Song referred me to Ryan's commit when I was working on the "mm:
zswap swap-out of large folios" patch-series [1].

This patch propagates the benefits of the above change to page_io.c and
vmscan.c.  As a result, there is one less reason to have the ifdef THP in
these code sections.

[1]: https://patchwork.kernel.org/project/linux-mm/list/?series=894347

Link: https://lkml.kernel.org/r/20241002225822.9006-1-kanchana.p.sridhar@intel.com
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Wajdi Feghali <wajdi.k.feghali@intel.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_io.c |    2 +-
 mm/vmscan.c  |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/mm/page_io.c~mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic
+++ a/mm/page_io.c
@@ -289,8 +289,8 @@ static inline void count_swpout_vm_event
 		count_memcg_folio_events(folio, THP_SWPOUT, 1);
 		count_vm_event(THP_SWPOUT);
 	}
-	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
 #endif
+	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
 	count_memcg_folio_events(folio, PSWPOUT, folio_nr_pages(folio));
 	count_vm_events(PSWPOUT, folio_nr_pages(folio));
 }
--- a/mm/vmscan.c~mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic
+++ a/mm/vmscan.c
@@ -1257,8 +1257,8 @@ retry:
 							THP_SWPOUT_FALLBACK, 1);
 						count_vm_event(THP_SWPOUT_FALLBACK);
 					}
-					count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
 #endif
+					count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
 					if (!add_to_swap(folio))
 						goto activate_locked_split;
 				}
_

Patches currently in -mm which might be from kanchana.p.sridhar@intel.com are

mm-zswap-delete-comments-for-value-member-of-struct-zswap_entry.patch
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
mm-zswap-zswap_store_page-will-initialize-entry-after-adding-to-xarray.patch
mm-swap-make-some-count_mthp_stat-call-sites-be-thp-agnostic.patch