[PATCH v2] mm: swap: Call count_mthp_stat() outside ifdef CONFIG_TRANSPARENT_HUGEPAGE.

[PATCH v2] mm: swap: Call count_mthp_stat() outside ifdef CONFIG_TRANSPARENT_HUGEPAGE.

[Kanchana P Sridhar]

This patch moves the call to count_mthp_stat() in count_swpout_vm_event()
and in shrink_folio_list() to be outside the
"ifdef CONFIG_TRANSPARENT_HUGEPAGE" based on changes made in commit
246d3aa3e531 ("mm: cleanup count_mthp_stat() definition").

Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
---
 mm/page_io.c | 2 +-
 mm/vmscan.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index 4aa34862676f..a28d28b6b3ce 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -289,8 +289,8 @@ 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_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));
 }
diff --git a/mm/vmscan.c b/mm/vmscan.c
index dc7a285b256b..50dc06d55b1d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1257,8 +1257,8 @@ 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_SWPOUT_FALLBACK);
 #endif
+					count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
 					if (!add_to_swap(folio))
 						goto activate_locked_split;
 				}
-- 
2.27.0

Re: [PATCH v2] mm: swap: Call count_mthp_stat() outside ifdef CONFIG_TRANSPARENT_HUGEPAGE.

[Andrew Morton]

On Wed,  2 Oct 2024 12:55:47 -0700 Kanchana P Sridhar <kanchana.p.sridhar@intel.com> wrote:

> This patch moves the call to count_mthp_stat() in count_swpout_vm_event()
> and in shrink_folio_list() to be outside the
> "ifdef CONFIG_TRANSPARENT_HUGEPAGE"

This is very apparent from reading the patch.  Changelogs and code
comments should explain "why", and avoid explaining "what".

> based on changes made in commit
> 246d3aa3e531 ("mm: cleanup count_mthp_stat() definition").

And I don't think that explains the reasons for this change either.

So please resend with a changelog which fully explains the reasons for
making this alteration.

RE: [PATCH v2] mm: swap: Call count_mthp_stat() outside ifdef CONFIG_TRANSPARENT_HUGEPAGE.

[Sridhar, Kanchana P]

> -----Original Message-----
> From: Andrew Morton <akpm@linux-foundation.org>
> Sent: Wednesday, October 2, 2024 1:37 PM
> To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>
> Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org;
> hannes@cmpxchg.org; yosryahmed@google.com; nphamcs@gmail.com;
> chengming.zhou@linux.dev; ryan.roberts@arm.com; Huang, Ying
> <ying.huang@intel.com>; 21cnbao@gmail.com; Feghali, Wajdi K
> <wajdi.k.feghali@intel.com>; Gopal, Vinodh <vinodh.gopal@intel.com>
> Subject: Re: [PATCH v2] mm: swap: Call count_mthp_stat() outside ifdef
> CONFIG_TRANSPARENT_HUGEPAGE.
> 
> On Wed,  2 Oct 2024 12:55:47 -0700 Kanchana P Sridhar
> <kanchana.p.sridhar@intel.com> wrote:
> 
> > This patch moves the call to count_mthp_stat() in
> count_swpout_vm_event()
> > and in shrink_folio_list() to be outside the
> > "ifdef CONFIG_TRANSPARENT_HUGEPAGE"
> 
> This is very apparent from reading the patch.  Changelogs and code
> comments should explain "why", and avoid explaining "what".
> 
> > based on changes made in commit
> > 246d3aa3e531 ("mm: cleanup count_mthp_stat() definition").
> 
> And I don't think that explains the reasons for this change either.
> 
> So please resend with a changelog which fully explains the reasons for
> making this alteration.

Thanks Andrew, for the comments. Sure, I will resend with these
suggestions incorporated!

Thanks,
Kanchana