Received-SPF: pass (google.com: domain of linux-kernel+bounces-211650-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Precedence: bulk
MIME-Version: 1.0
References: <cover.1718090413.git.baolin.wang@linux.alibaba.com>
 <4fd9e467d49ae4a747e428bcd821c7d13125ae67.1718090413.git.baolin.wang@linux.alibaba.com>
 <CAK1f24=Rz4qPyw9pfTHTAuQO6Yv9mFHccjCd75a0kvHvCBH3uA@mail.gmail.com> <df06474c-110f-459d-a093-76074e0b5666@linux.alibaba.com>
In-Reply-To: <df06474c-110f-459d-a093-76074e0b5666@linux.alibaba.com>
From: Lance Yang <ioworker0@gmail.com>
Date: Wed, 12 Jun 2024 22:16:20 +0800
Message-ID: <CAK1f24=4tNTvT0Kr2wuERe11M1ZkYorv9rTNTtehOFmGSSt+Nw@mail.gmail.com>
Subject: Re: [PATCH v5 6/6] mm: shmem: add mTHP counters for anonymous shmem
To: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: akpm@linux-foundation.org, hughd@google.com, willy@infradead.org, 
	david@redhat.com, wangkefeng.wang@huawei.com, ying.huang@intel.com, 
	21cnbao@gmail.com, ryan.roberts@arm.com, shy828301@gmail.com, ziy@nvidia.com, 
	da.gomez@samsung.com, p.raghav@samsung.com, linux-mm@kvack.org, 
	linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Wed, Jun 12, 2024 at 5:28=E2=80=AFPM Baolin Wang
<baolin.wang@linux.alibaba.com> wrote:
>
>
>
> On 2024/6/12 16:04, Lance Yang wrote:
> > Hi Baolin,
> >
> > On Tue, Jun 11, 2024 at 6:11=E2=80=AFPM Baolin Wang
> > <baolin.wang@linux.alibaba.com> wrote:
> >>
> >> Add mTHP counters for anonymous shmem.
> >>
> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> >> ---
> >>   include/linux/huge_mm.h |  3 +++
> >>   mm/huge_memory.c        |  6 ++++++
> >>   mm/shmem.c              | 18 +++++++++++++++---
> >>   3 files changed, 24 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> >> index 909cfc67521d..212cca384d7e 100644
> >> --- a/include/linux/huge_mm.h
> >> +++ b/include/linux/huge_mm.h
> >> @@ -281,6 +281,9 @@ enum mthp_stat_item {
> >>          MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
> >>          MTHP_STAT_SWPOUT,
> >>          MTHP_STAT_SWPOUT_FALLBACK,
> >> +       MTHP_STAT_FILE_ALLOC,
> >> +       MTHP_STAT_FILE_FALLBACK,
> >> +       MTHP_STAT_FILE_FALLBACK_CHARGE,
> >>          __MTHP_STAT_COUNT
> >>   };
> >>
> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> >> index 1360a1903b66..3fbcd77f5957 100644
> >> --- a/mm/huge_memory.c
> >> +++ b/mm/huge_memory.c
> >> @@ -555,6 +555,9 @@ DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_ST=
AT_ANON_FAULT_FALLBACK);
> >>   DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAU=
LT_FALLBACK_CHARGE);
> >>   DEFINE_MTHP_STAT_ATTR(swpout, MTHP_STAT_SWPOUT);
> >>   DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK);
> >> +DEFINE_MTHP_STAT_ATTR(file_alloc, MTHP_STAT_FILE_ALLOC);
> >> +DEFINE_MTHP_STAT_ATTR(file_fallback, MTHP_STAT_FILE_FALLBACK);
> >> +DEFINE_MTHP_STAT_ATTR(file_fallback_charge, MTHP_STAT_FILE_FALLBACK_C=
HARGE);
> >>
> >>   static struct attribute *stats_attrs[] =3D {
> >>          &anon_fault_alloc_attr.attr,
> >> @@ -562,6 +565,9 @@ static struct attribute *stats_attrs[] =3D {
> >>          &anon_fault_fallback_charge_attr.attr,
> >>          &swpout_attr.attr,
> >>          &swpout_fallback_attr.attr,
> >> +       &file_alloc_attr.attr,
> >> +       &file_fallback_attr.attr,
> >> +       &file_fallback_charge_attr.attr,
> >>          NULL,
> >>   };
> >>
> >> diff --git a/mm/shmem.c b/mm/shmem.c
> >> index f5469c357be6..99bd3c34f0fb 100644
> >> --- a/mm/shmem.c
> >> +++ b/mm/shmem.c
> >> @@ -1773,6 +1773,9 @@ static struct folio *shmem_alloc_and_add_folio(s=
truct vm_fault *vmf,
> >>
> >>                          if (pages =3D=3D HPAGE_PMD_NR)
> >>                                  count_vm_event(THP_FILE_FALLBACK);
> >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> >> +                       count_mthp_stat(order, MTHP_STAT_FILE_FALLBACK=
);
> >> +#endif
> >
> > Using the conditional compilation directives here is a bit weird :)
> > Would there be any issues if we were to drop them?
>
> Will cause building errors if CONFIG_TRANSPARENT_HUGEPAGE is not enabled.

Sorry, I got it wrong :p

>
> >
> > Since THP_FILE_FALLBACK is working as expected, MTHP_STAT_FILE_FALLBACK
> > should work as well without the conditional compilation directives, IIU=
C.
>
> No, you should take a look at how count_mthp_stat() is defined :)

You're correct. count_mthp_stat() does cause a compilation error without th=
em
when CONFIG_TRANSPARENT_HUGEPAGE is not defined.

Thanks,
Lance