[PATCH v3] mm: add per-order mTHP swpin counters

Barry Song posted 1 patch 1 day, 11 hours ago
Documentation/admin-guide/mm/transhuge.rst | 4 ++++
include/linux/huge_mm.h                    | 1 +
mm/huge_memory.c                           | 3 +++
mm/page_io.c                               | 3 +++
4 files changed, 11 insertions(+)
[PATCH v3] mm: add per-order mTHP swpin counters
Posted by Barry Song 1 day, 11 hours ago
From: Barry Song <v-songbaohua@oppo.com>

This helps profile the sizes of folios being swapped in. Currently,
only mTHP swap-out is being counted.
The new interface can be found at:
/sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats/swpin
For example,
$ cat /sys/kernel/mm/transparent_hugepage/hugepages-64kB/stats/swpin
12809
$ cat /sys/kernel/mm/transparent_hugepage/hugepages-32kB/stats/swpin
4763

Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Cc: Usama Arif <usamaarif642@gmail.com>
---
 -v3: minor refine changelog per Huang, Ying. thanks!

 Documentation/admin-guide/mm/transhuge.rst | 4 ++++
 include/linux/huge_mm.h                    | 1 +
 mm/huge_memory.c                           | 3 +++
 mm/page_io.c                               | 3 +++
 4 files changed, 11 insertions(+)

diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index 2a171ed5206e..5caa3fb2feb1 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -534,6 +534,10 @@ zswpout
 	is incremented every time a huge page is swapped out to zswap in one
 	piece without splitting.
 
+swpin
+	is incremented every time a huge page is swapped in from a non-zswap
+	swap device in one piece.
+
 swpout
 	is incremented every time a huge page is swapped out to a non-zswap
 	swap device in one piece without splitting.
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index c59e5aa9b081..b94c2e8ee918 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -120,6 +120,7 @@ enum mthp_stat_item {
 	MTHP_STAT_ANON_FAULT_FALLBACK,
 	MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
 	MTHP_STAT_ZSWPOUT,
+	MTHP_STAT_SWPIN,
 	MTHP_STAT_SWPOUT,
 	MTHP_STAT_SWPOUT_FALLBACK,
 	MTHP_STAT_SHMEM_ALLOC,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b26c6503e993..f92068864469 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -616,6 +616,7 @@ 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(swpin, MTHP_STAT_SWPIN);
 DEFINE_MTHP_STAT_ATTR(swpout, MTHP_STAT_SWPOUT);
 DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK);
 #ifdef CONFIG_SHMEM
@@ -635,6 +636,7 @@ static struct attribute *anon_stats_attrs[] = {
 	&anon_fault_fallback_charge_attr.attr,
 #ifndef CONFIG_SHMEM
 	&zswpout_attr.attr,
+	&swpin_attr.attr,
 	&swpout_attr.attr,
 	&swpout_fallback_attr.attr,
 #endif
@@ -666,6 +668,7 @@ static struct attribute_group file_stats_attr_grp = {
 static struct attribute *any_stats_attrs[] = {
 #ifdef CONFIG_SHMEM
 	&zswpout_attr.attr,
+	&swpin_attr.attr,
 	&swpout_attr.attr,
 	&swpout_fallback_attr.attr,
 #endif
diff --git a/mm/page_io.c b/mm/page_io.c
index c69fab5060a1..5d9b6e6cf96c 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -487,6 +487,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
 		for (p = 0; p < sio->pages; p++) {
 			struct folio *folio = page_folio(sio->bvec[p].bv_page);
 
+			count_mthp_stat(folio_order(folio), MTHP_STAT_SWPIN);
 			count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
 			folio_mark_uptodate(folio);
 			folio_unlock(folio);
@@ -573,6 +574,7 @@ static void swap_read_folio_bdev_sync(struct folio *folio,
 	 * attempt to access it in the page fault retry time check.
 	 */
 	get_task_struct(current);
+	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPIN);
 	count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
 	count_vm_events(PSWPIN, folio_nr_pages(folio));
 	submit_bio_wait(&bio);
@@ -589,6 +591,7 @@ static void swap_read_folio_bdev_async(struct folio *folio,
 	bio->bi_iter.bi_sector = swap_folio_sector(folio);
 	bio->bi_end_io = end_swap_bio_read;
 	bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
+	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPIN);
 	count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
 	count_vm_events(PSWPIN, folio_nr_pages(folio));
 	submit_bio(bio);
-- 
2.39.3 (Apple Git-146)
Re: [PATCH v3] mm: add per-order mTHP swpin counters
Posted by Huang, Ying 1 day, 11 hours ago
Barry Song <21cnbao@gmail.com> writes:

> From: Barry Song <v-songbaohua@oppo.com>
>
> This helps profile the sizes of folios being swapped in. Currently,
> only mTHP swap-out is being counted.
> The new interface can be found at:
> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats/swpin
> For example,
> $ cat /sys/kernel/mm/transparent_hugepage/hugepages-64kB/stats/swpin
> 12809
> $ cat /sys/kernel/mm/transparent_hugepage/hugepages-32kB/stats/swpin
> 4763
>
> Signed-off-by: Barry Song <v-songbaohua@oppo.com>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Cc: Chris Li <chrisl@kernel.org>
> Cc: Yosry Ahmed <yosryahmed@google.com>
> Cc: "Huang, Ying" <ying.huang@intel.com>
> Cc: Kairui Song <kasong@tencent.com>
> Cc: Ryan Roberts <ryan.roberts@arm.com>
> Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
> Cc: Usama Arif <usamaarif642@gmail.com>
> ---
>  -v3: minor refine changelog per Huang, Ying. thanks!
>
>  Documentation/admin-guide/mm/transhuge.rst | 4 ++++
>  include/linux/huge_mm.h                    | 1 +
>  mm/huge_memory.c                           | 3 +++
>  mm/page_io.c                               | 3 +++
>  4 files changed, 11 insertions(+)
>
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index 2a171ed5206e..5caa3fb2feb1 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -534,6 +534,10 @@ zswpout
>  	is incremented every time a huge page is swapped out to zswap in one
>  	piece without splitting.
>  
> +swpin
> +	is incremented every time a huge page is swapped in from a non-zswap
> +	swap device in one piece.
> +
>  swpout
>  	is incremented every time a huge page is swapped out to a non-zswap
>  	swap device in one piece without splitting.

In Documentation/ABI/testing/sysfs-kernel-mm-transparent-hugepage, I
found

"
What:		/sys/kernel/mm/transparent_hugepage/
Date:		April 2024
Contact:	Linux memory management mailing list <linux-mm@kvack.org>
Description:
		/sys/kernel/mm/transparent_hugepage/ contains a number of files and
		subdirectories,

			- defrag
			- enabled
			- hpage_pmd_size
			- khugepaged
			- shmem_enabled
			- use_zero_page
			- subdirectories of the form hugepages-<size>kB, where <size>
			  is the page size of the hugepages supported by the kernel/CPU
			  combination.

		See Documentation/admin-guide/mm/transhuge.rst for details.
"

So, Documentation/admin-guide/mm/transhuge.rst will be used as ABI
document?

[snip]

--
Best Regards,
Huang, Ying
Re: [PATCH v3] mm: add per-order mTHP swpin counters
Posted by Barry Song 1 day, 11 hours ago
On Thu, Oct 31, 2024 at 9:09 PM Huang, Ying <ying.huang@intel.com> wrote:
>
> Barry Song <21cnbao@gmail.com> writes:
>
> > From: Barry Song <v-songbaohua@oppo.com>
> >
> > This helps profile the sizes of folios being swapped in. Currently,
> > only mTHP swap-out is being counted.
> > The new interface can be found at:
> > /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats/swpin
> > For example,
> > $ cat /sys/kernel/mm/transparent_hugepage/hugepages-64kB/stats/swpin
> > 12809
> > $ cat /sys/kernel/mm/transparent_hugepage/hugepages-32kB/stats/swpin
> > 4763
> >
> > Signed-off-by: Barry Song <v-songbaohua@oppo.com>
> > Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> > Acked-by: David Hildenbrand <david@redhat.com>
> > Cc: Chris Li <chrisl@kernel.org>
> > Cc: Yosry Ahmed <yosryahmed@google.com>
> > Cc: "Huang, Ying" <ying.huang@intel.com>
> > Cc: Kairui Song <kasong@tencent.com>
> > Cc: Ryan Roberts <ryan.roberts@arm.com>
> > Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
> > Cc: Usama Arif <usamaarif642@gmail.com>
> > ---
> >  -v3: minor refine changelog per Huang, Ying. thanks!
> >
> >  Documentation/admin-guide/mm/transhuge.rst | 4 ++++
> >  include/linux/huge_mm.h                    | 1 +
> >  mm/huge_memory.c                           | 3 +++
> >  mm/page_io.c                               | 3 +++
> >  4 files changed, 11 insertions(+)
> >
> > diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> > index 2a171ed5206e..5caa3fb2feb1 100644
> > --- a/Documentation/admin-guide/mm/transhuge.rst
> > +++ b/Documentation/admin-guide/mm/transhuge.rst
> > @@ -534,6 +534,10 @@ zswpout
> >       is incremented every time a huge page is swapped out to zswap in one
> >       piece without splitting.
> >
> > +swpin
> > +     is incremented every time a huge page is swapped in from a non-zswap
> > +     swap device in one piece.
> > +
> >  swpout
> >       is incremented every time a huge page is swapped out to a non-zswap
> >       swap device in one piece without splitting.
>
> In Documentation/ABI/testing/sysfs-kernel-mm-transparent-hugepage, I
> found
>
> "
> What:           /sys/kernel/mm/transparent_hugepage/
> Date:           April 2024
> Contact:        Linux memory management mailing list <linux-mm@kvack.org>
> Description:
>                 /sys/kernel/mm/transparent_hugepage/ contains a number of files and
>                 subdirectories,
>
>                         - defrag
>                         - enabled
>                         - hpage_pmd_size
>                         - khugepaged
>                         - shmem_enabled
>                         - use_zero_page
>                         - subdirectories of the form hugepages-<size>kB, where <size>
>                           is the page size of the hugepages supported by the kernel/CPU
>                           combination.
>
>                 See Documentation/admin-guide/mm/transhuge.rst for details.
> "
>
> So, Documentation/admin-guide/mm/transhuge.rst will be used as ABI
> document?

Yes. this follows:

sysfs-kernel-mm-hugepages:              See
Documentation/admin-guide/mm/hugetlbpage.rst for details.
sysfs-kernel-mm-ksm:            See Documentation/mm/ksm.rst for more
information.
sysfs-kernel-mm-transparent-hugepage:           See
Documentation/admin-guide/mm/transhuge.rst for details.


>
> [snip]
>
> --
> Best Regards,
> Huang, Ying

Thanks
barry
Re: [PATCH v3] mm: add per-order mTHP swpin counters
Posted by Huang, Ying 1 day, 10 hours ago
Barry Song <21cnbao@gmail.com> writes:

> On Thu, Oct 31, 2024 at 9:09 PM Huang, Ying <ying.huang@intel.com> wrote:
>>
>> Barry Song <21cnbao@gmail.com> writes:
>>
>> > From: Barry Song <v-songbaohua@oppo.com>
>> >
>> > This helps profile the sizes of folios being swapped in. Currently,
>> > only mTHP swap-out is being counted.
>> > The new interface can be found at:
>> > /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats/swpin
>> > For example,
>> > $ cat /sys/kernel/mm/transparent_hugepage/hugepages-64kB/stats/swpin
>> > 12809
>> > $ cat /sys/kernel/mm/transparent_hugepage/hugepages-32kB/stats/swpin
>> > 4763
>> >
>> > Signed-off-by: Barry Song <v-songbaohua@oppo.com>
>> > Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>> > Acked-by: David Hildenbrand <david@redhat.com>
>> > Cc: Chris Li <chrisl@kernel.org>
>> > Cc: Yosry Ahmed <yosryahmed@google.com>
>> > Cc: "Huang, Ying" <ying.huang@intel.com>
>> > Cc: Kairui Song <kasong@tencent.com>
>> > Cc: Ryan Roberts <ryan.roberts@arm.com>
>> > Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
>> > Cc: Usama Arif <usamaarif642@gmail.com>
>> > ---
>> >  -v3: minor refine changelog per Huang, Ying. thanks!
>> >
>> >  Documentation/admin-guide/mm/transhuge.rst | 4 ++++
>> >  include/linux/huge_mm.h                    | 1 +
>> >  mm/huge_memory.c                           | 3 +++
>> >  mm/page_io.c                               | 3 +++
>> >  4 files changed, 11 insertions(+)
>> >
>> > diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
>> > index 2a171ed5206e..5caa3fb2feb1 100644
>> > --- a/Documentation/admin-guide/mm/transhuge.rst
>> > +++ b/Documentation/admin-guide/mm/transhuge.rst
>> > @@ -534,6 +534,10 @@ zswpout
>> >       is incremented every time a huge page is swapped out to zswap in one
>> >       piece without splitting.
>> >
>> > +swpin
>> > +     is incremented every time a huge page is swapped in from a non-zswap
>> > +     swap device in one piece.
>> > +
>> >  swpout
>> >       is incremented every time a huge page is swapped out to a non-zswap
>> >       swap device in one piece without splitting.
>>
>> In Documentation/ABI/testing/sysfs-kernel-mm-transparent-hugepage, I
>> found
>>
>> "
>> What:           /sys/kernel/mm/transparent_hugepage/
>> Date:           April 2024
>> Contact:        Linux memory management mailing list <linux-mm@kvack.org>
>> Description:
>>                 /sys/kernel/mm/transparent_hugepage/ contains a number of files and
>>                 subdirectories,
>>
>>                         - defrag
>>                         - enabled
>>                         - hpage_pmd_size
>>                         - khugepaged
>>                         - shmem_enabled
>>                         - use_zero_page
>>                         - subdirectories of the form hugepages-<size>kB, where <size>
>>                           is the page size of the hugepages supported by the kernel/CPU
>>                           combination.
>>
>>                 See Documentation/admin-guide/mm/transhuge.rst for details.
>> "
>>
>> So, Documentation/admin-guide/mm/transhuge.rst will be used as ABI
>> document?
>
> Yes. this follows:
>
> sysfs-kernel-mm-hugepages:              See
> Documentation/admin-guide/mm/hugetlbpage.rst for details.
> sysfs-kernel-mm-ksm:            See Documentation/mm/ksm.rst for more
> information.
> sysfs-kernel-mm-transparent-hugepage:           See
> Documentation/admin-guide/mm/transhuge.rst for details.
>

Got it!  Thanks!  Feel free to add

Acked-by: "Huang, Ying" <ying.huang@intel.com>

in the future versions.

--
Best Regards,
Huang, Ying