Currently, the split counters in THP statistics no longer include
PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
counters to monitor the frequency of mTHP splits. This will help developers
better analyze and optimize system performance.
/sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
split
split_failed
split_deferred
Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
Signed-off-by: Lance Yang <ioworker0@gmail.com>
---
include/linux/huge_mm.h | 3 +++
mm/huge_memory.c | 19 ++++++++++++++-----
2 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 212cca384d7e..cee3c5da8f0e 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -284,6 +284,9 @@ enum mthp_stat_item {
MTHP_STAT_FILE_ALLOC,
MTHP_STAT_FILE_FALLBACK,
MTHP_STAT_FILE_FALLBACK_CHARGE,
+ MTHP_STAT_SPLIT,
+ MTHP_STAT_SPLIT_FAILED,
+ MTHP_STAT_SPLIT_DEFERRED,
__MTHP_STAT_COUNT
};
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c7ce28f6b7f3..a633206375af 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -559,6 +559,9 @@ 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_CHARGE);
+DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
+DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
+DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
static struct attribute *stats_attrs[] = {
&anon_fault_alloc_attr.attr,
@@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
&file_alloc_attr.attr,
&file_fallback_attr.attr,
&file_fallback_charge_attr.attr,
+ &split_attr.attr,
+ &split_failed_attr.attr,
+ &split_deferred_attr.attr,
NULL,
};
@@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
struct anon_vma *anon_vma = NULL;
struct address_space *mapping = NULL;
- bool is_thp = folio_test_pmd_mappable(folio);
+ int order = folio_order(folio);
int extra_pins, ret;
pgoff_t end;
bool is_hzp;
@@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
- if (new_order >= folio_order(folio))
+ if (new_order >= order)
return -EINVAL;
if (folio_test_anon(folio)) {
@@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
i_mmap_unlock_read(mapping);
out:
xas_destroy(&xas);
- if (is_thp)
+ if (order >= HPAGE_PMD_ORDER)
count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
+ count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
return ret;
}
@@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
#ifdef CONFIG_MEMCG
struct mem_cgroup *memcg = folio_memcg(folio);
#endif
+ int order = folio_order(folio);
unsigned long flags;
/*
* Order 1 folios have no space for a deferred list, but we also
* won't waste much memory by not adding them to the deferred list.
*/
- if (folio_order(folio) <= 1)
+ if (order <= 1)
return;
/*
@@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
if (list_empty(&folio->_deferred_list)) {
- if (folio_test_pmd_mappable(folio))
+ if (order >= HPAGE_PMD_ORDER)
count_vm_event(THP_DEFERRED_SPLIT_PAGE);
+ count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
ds_queue->split_queue_len++;
#ifdef CONFIG_MEMCG
--
2.45.2On 28/06/2024 14:07, Lance Yang wrote:
> Currently, the split counters in THP statistics no longer include
> PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
> counters to monitor the frequency of mTHP splits. This will help developers
> better analyze and optimize system performance.
>
> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
> split
> split_failed
> split_deferred
>
> Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
> Signed-off-by: Lance Yang <ioworker0@gmail.com>
LGTM!
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
> include/linux/huge_mm.h | 3 +++
> mm/huge_memory.c | 19 ++++++++++++++-----
> 2 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 212cca384d7e..cee3c5da8f0e 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -284,6 +284,9 @@ enum mthp_stat_item {
> MTHP_STAT_FILE_ALLOC,
> MTHP_STAT_FILE_FALLBACK,
> MTHP_STAT_FILE_FALLBACK_CHARGE,
> + MTHP_STAT_SPLIT,
> + MTHP_STAT_SPLIT_FAILED,
> + MTHP_STAT_SPLIT_DEFERRED,
> __MTHP_STAT_COUNT
> };
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c7ce28f6b7f3..a633206375af 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -559,6 +559,9 @@ 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_CHARGE);
> +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
> +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
> +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
>
> static struct attribute *stats_attrs[] = {
> &anon_fault_alloc_attr.attr,
> @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
> &file_alloc_attr.attr,
> &file_fallback_attr.attr,
> &file_fallback_charge_attr.attr,
> + &split_attr.attr,
> + &split_failed_attr.attr,
> + &split_deferred_attr.attr,
> NULL,
> };
>
> @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
> struct anon_vma *anon_vma = NULL;
> struct address_space *mapping = NULL;
> - bool is_thp = folio_test_pmd_mappable(folio);
> + int order = folio_order(folio);
> int extra_pins, ret;
> pgoff_t end;
> bool is_hzp;
> @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
> VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
>
> - if (new_order >= folio_order(folio))
> + if (new_order >= order)
> return -EINVAL;
>
> if (folio_test_anon(folio)) {
> @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> i_mmap_unlock_read(mapping);
> out:
> xas_destroy(&xas);
> - if (is_thp)
> + if (order >= HPAGE_PMD_ORDER)
> count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
> + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
> return ret;
> }
>
> @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
> #ifdef CONFIG_MEMCG
> struct mem_cgroup *memcg = folio_memcg(folio);
> #endif
> + int order = folio_order(folio);
> unsigned long flags;
>
> /*
> * Order 1 folios have no space for a deferred list, but we also
> * won't waste much memory by not adding them to the deferred list.
> */
> - if (folio_order(folio) <= 1)
> + if (order <= 1)
> return;
>
> /*
> @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
>
> spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
> if (list_empty(&folio->_deferred_list)) {
> - if (folio_test_pmd_mappable(folio))
> + if (order >= HPAGE_PMD_ORDER)
> count_vm_event(THP_DEFERRED_SPLIT_PAGE);
> + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
> list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
> ds_queue->split_queue_len++;
> #ifdef CONFIG_MEMCG
Hi Ryan,
On Mon, Jul 1, 2024 at 4:18 PM Ryan Roberts <ryan.roberts@arm.com> wrote:
>
> On 28/06/2024 14:07, Lance Yang wrote:
> > Currently, the split counters in THP statistics no longer include
> > PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
> > counters to monitor the frequency of mTHP splits. This will help developers
> > better analyze and optimize system performance.
> >
> > /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
> > split
> > split_failed
> > split_deferred
> >
> > Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
> > Signed-off-by: Lance Yang <ioworker0@gmail.com>
>
> LGTM!
>
> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Thanks for taking time to review!
Lance
>
> > ---
> > include/linux/huge_mm.h | 3 +++
> > mm/huge_memory.c | 19 ++++++++++++++-----
> > 2 files changed, 17 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> > index 212cca384d7e..cee3c5da8f0e 100644
> > --- a/include/linux/huge_mm.h
> > +++ b/include/linux/huge_mm.h
> > @@ -284,6 +284,9 @@ enum mthp_stat_item {
> > MTHP_STAT_FILE_ALLOC,
> > MTHP_STAT_FILE_FALLBACK,
> > MTHP_STAT_FILE_FALLBACK_CHARGE,
> > + MTHP_STAT_SPLIT,
> > + MTHP_STAT_SPLIT_FAILED,
> > + MTHP_STAT_SPLIT_DEFERRED,
> > __MTHP_STAT_COUNT
> > };
> >
> > diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> > index c7ce28f6b7f3..a633206375af 100644
> > --- a/mm/huge_memory.c
> > +++ b/mm/huge_memory.c
> > @@ -559,6 +559,9 @@ 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_CHARGE);
> > +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
> > +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
> > +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
> >
> > static struct attribute *stats_attrs[] = {
> > &anon_fault_alloc_attr.attr,
> > @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
> > &file_alloc_attr.attr,
> > &file_fallback_attr.attr,
> > &file_fallback_charge_attr.attr,
> > + &split_attr.attr,
> > + &split_failed_attr.attr,
> > + &split_deferred_attr.attr,
> > NULL,
> > };
> >
> > @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
> > struct anon_vma *anon_vma = NULL;
> > struct address_space *mapping = NULL;
> > - bool is_thp = folio_test_pmd_mappable(folio);
> > + int order = folio_order(folio);
> > int extra_pins, ret;
> > pgoff_t end;
> > bool is_hzp;
> > @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
> > VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
> >
> > - if (new_order >= folio_order(folio))
> > + if (new_order >= order)
> > return -EINVAL;
> >
> > if (folio_test_anon(folio)) {
> > @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > i_mmap_unlock_read(mapping);
> > out:
> > xas_destroy(&xas);
> > - if (is_thp)
> > + if (order >= HPAGE_PMD_ORDER)
> > count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
> > + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
> > return ret;
> > }
> >
> > @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
> > #ifdef CONFIG_MEMCG
> > struct mem_cgroup *memcg = folio_memcg(folio);
> > #endif
> > + int order = folio_order(folio);
> > unsigned long flags;
> >
> > /*
> > * Order 1 folios have no space for a deferred list, but we also
> > * won't waste much memory by not adding them to the deferred list.
> > */
> > - if (folio_order(folio) <= 1)
> > + if (order <= 1)
> > return;
> >
> > /*
> > @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
> >
> > spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
> > if (list_empty(&folio->_deferred_list)) {
> > - if (folio_test_pmd_mappable(folio))
> > + if (order >= HPAGE_PMD_ORDER)
> > count_vm_event(THP_DEFERRED_SPLIT_PAGE);
> > + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
> > list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
> > ds_queue->split_queue_len++;
> > #ifdef CONFIG_MEMCG
>
On Sat, Jun 29, 2024 at 1:09 AM Lance Yang <ioworker0@gmail.com> wrote:
>
> Currently, the split counters in THP statistics no longer include
> PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
> counters to monitor the frequency of mTHP splits. This will help developers
> better analyze and optimize system performance.
>
> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
> split
> split_failed
> split_deferred
>
> Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
> Signed-off-by: Lance Yang <ioworker0@gmail.com>
Personally, I'm not convinced that using a temporary variable order
makes the code
more readable. Functions like folio_test_pmd_mappable() seem more readable to
me. In any case, it's a minor issue.
Acked-by: Barry Song <baohua@kernel.org>
> ---
> include/linux/huge_mm.h | 3 +++
> mm/huge_memory.c | 19 ++++++++++++++-----
> 2 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 212cca384d7e..cee3c5da8f0e 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -284,6 +284,9 @@ enum mthp_stat_item {
> MTHP_STAT_FILE_ALLOC,
> MTHP_STAT_FILE_FALLBACK,
> MTHP_STAT_FILE_FALLBACK_CHARGE,
> + MTHP_STAT_SPLIT,
> + MTHP_STAT_SPLIT_FAILED,
> + MTHP_STAT_SPLIT_DEFERRED,
> __MTHP_STAT_COUNT
> };
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c7ce28f6b7f3..a633206375af 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -559,6 +559,9 @@ 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_CHARGE);
> +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
> +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
> +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
>
> static struct attribute *stats_attrs[] = {
> &anon_fault_alloc_attr.attr,
> @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
> &file_alloc_attr.attr,
> &file_fallback_attr.attr,
> &file_fallback_charge_attr.attr,
> + &split_attr.attr,
> + &split_failed_attr.attr,
> + &split_deferred_attr.attr,
> NULL,
> };
>
> @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
> struct anon_vma *anon_vma = NULL;
> struct address_space *mapping = NULL;
> - bool is_thp = folio_test_pmd_mappable(folio);
> + int order = folio_order(folio);
> int extra_pins, ret;
> pgoff_t end;
> bool is_hzp;
> @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
> VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
>
> - if (new_order >= folio_order(folio))
> + if (new_order >= order)
> return -EINVAL;
>
> if (folio_test_anon(folio)) {
> @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> i_mmap_unlock_read(mapping);
> out:
> xas_destroy(&xas);
> - if (is_thp)
> + if (order >= HPAGE_PMD_ORDER)
> count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
> + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
> return ret;
> }
>
> @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
> #ifdef CONFIG_MEMCG
> struct mem_cgroup *memcg = folio_memcg(folio);
> #endif
> + int order = folio_order(folio);
> unsigned long flags;
>
> /*
> * Order 1 folios have no space for a deferred list, but we also
> * won't waste much memory by not adding them to the deferred list.
> */
> - if (folio_order(folio) <= 1)
> + if (order <= 1)
> return;
>
> /*
> @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
>
> spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
> if (list_empty(&folio->_deferred_list)) {
> - if (folio_test_pmd_mappable(folio))
> + if (order >= HPAGE_PMD_ORDER)
> count_vm_event(THP_DEFERRED_SPLIT_PAGE);
> + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
> list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
> ds_queue->split_queue_len++;
> #ifdef CONFIG_MEMCG
> --
> 2.45.2
>
On 2024/7/1 08:02, Barry Song wrote:
> On Sat, Jun 29, 2024 at 1:09 AM Lance Yang <ioworker0@gmail.com> wrote:
>>
>> Currently, the split counters in THP statistics no longer include
>> PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
>> counters to monitor the frequency of mTHP splits. This will help developers
>> better analyze and optimize system performance.
>>
>> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
>> split
>> split_failed
>> split_deferred
>>
>> Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
>> Signed-off-by: Lance Yang <ioworker0@gmail.com>
>
> Personally, I'm not convinced that using a temporary variable order
> makes the code
> more readable. Functions like folio_test_pmd_mappable() seem more readable to
> me. In any case, it's a minor issue.
Yes, I have the same opinion as Barry. With that:
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Acked-by: Barry Song <baohua@kernel.org>
>
>> ---
>> include/linux/huge_mm.h | 3 +++
>> mm/huge_memory.c | 19 ++++++++++++++-----
>> 2 files changed, 17 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>> index 212cca384d7e..cee3c5da8f0e 100644
>> --- a/include/linux/huge_mm.h
>> +++ b/include/linux/huge_mm.h
>> @@ -284,6 +284,9 @@ enum mthp_stat_item {
>> MTHP_STAT_FILE_ALLOC,
>> MTHP_STAT_FILE_FALLBACK,
>> MTHP_STAT_FILE_FALLBACK_CHARGE,
>> + MTHP_STAT_SPLIT,
>> + MTHP_STAT_SPLIT_FAILED,
>> + MTHP_STAT_SPLIT_DEFERRED,
>> __MTHP_STAT_COUNT
>> };
>>
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index c7ce28f6b7f3..a633206375af 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -559,6 +559,9 @@ 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_CHARGE);
>> +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
>> +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
>> +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
>>
>> static struct attribute *stats_attrs[] = {
>> &anon_fault_alloc_attr.attr,
>> @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
>> &file_alloc_attr.attr,
>> &file_fallback_attr.attr,
>> &file_fallback_charge_attr.attr,
>> + &split_attr.attr,
>> + &split_failed_attr.attr,
>> + &split_deferred_attr.attr,
>> NULL,
>> };
>>
>> @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>> XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
>> struct anon_vma *anon_vma = NULL;
>> struct address_space *mapping = NULL;
>> - bool is_thp = folio_test_pmd_mappable(folio);
>> + int order = folio_order(folio);
>> int extra_pins, ret;
>> pgoff_t end;
>> bool is_hzp;
>> @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>> VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
>> VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
>>
>> - if (new_order >= folio_order(folio))
>> + if (new_order >= order)
>> return -EINVAL;
>>
>> if (folio_test_anon(folio)) {
>> @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>> i_mmap_unlock_read(mapping);
>> out:
>> xas_destroy(&xas);
>> - if (is_thp)
>> + if (order >= HPAGE_PMD_ORDER)
>> count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
>> + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
>> return ret;
>> }
>>
>> @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
>> #ifdef CONFIG_MEMCG
>> struct mem_cgroup *memcg = folio_memcg(folio);
>> #endif
>> + int order = folio_order(folio);
>> unsigned long flags;
>>
>> /*
>> * Order 1 folios have no space for a deferred list, but we also
>> * won't waste much memory by not adding them to the deferred list.
>> */
>> - if (folio_order(folio) <= 1)
>> + if (order <= 1)
>> return;
>>
>> /*
>> @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
>>
>> spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
>> if (list_empty(&folio->_deferred_list)) {
>> - if (folio_test_pmd_mappable(folio))
>> + if (order >= HPAGE_PMD_ORDER)
>> count_vm_event(THP_DEFERRED_SPLIT_PAGE);
>> + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
>> list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
>> ds_queue->split_queue_len++;
>> #ifdef CONFIG_MEMCG
>> --
>> 2.45.2
>>
Hi Baolin,
Thanks for taking time to review!
On Mon, Jul 1, 2024 at 10:23 AM Baolin Wang
<baolin.wang@linux.alibaba.com> wrote:
>
>
>
> On 2024/7/1 08:02, Barry Song wrote:
> > On Sat, Jun 29, 2024 at 1:09 AM Lance Yang <ioworker0@gmail.com> wrote:
> >>
> >> Currently, the split counters in THP statistics no longer include
> >> PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
> >> counters to monitor the frequency of mTHP splits. This will help developers
> >> better analyze and optimize system performance.
> >>
> >> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
> >> split
> >> split_failed
> >> split_deferred
> >>
> >> Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
> >> Signed-off-by: Lance Yang <ioworker0@gmail.com>
> >
> > Personally, I'm not convinced that using a temporary variable order
> > makes the code
> > more readable. Functions like folio_test_pmd_mappable() seem more readable to
> > me. In any case, it's a minor issue.
>
> Yes, I have the same opinion as Barry. With that:
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Thanks again for your opinion!
Lance
>
>
> > Acked-by: Barry Song <baohua@kernel.org>
> >
> >> ---
> >> include/linux/huge_mm.h | 3 +++
> >> mm/huge_memory.c | 19 ++++++++++++++-----
> >> 2 files changed, 17 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> >> index 212cca384d7e..cee3c5da8f0e 100644
> >> --- a/include/linux/huge_mm.h
> >> +++ b/include/linux/huge_mm.h
> >> @@ -284,6 +284,9 @@ enum mthp_stat_item {
> >> MTHP_STAT_FILE_ALLOC,
> >> MTHP_STAT_FILE_FALLBACK,
> >> MTHP_STAT_FILE_FALLBACK_CHARGE,
> >> + MTHP_STAT_SPLIT,
> >> + MTHP_STAT_SPLIT_FAILED,
> >> + MTHP_STAT_SPLIT_DEFERRED,
> >> __MTHP_STAT_COUNT
> >> };
> >>
> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> >> index c7ce28f6b7f3..a633206375af 100644
> >> --- a/mm/huge_memory.c
> >> +++ b/mm/huge_memory.c
> >> @@ -559,6 +559,9 @@ 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_CHARGE);
> >> +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
> >> +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
> >> +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
> >>
> >> static struct attribute *stats_attrs[] = {
> >> &anon_fault_alloc_attr.attr,
> >> @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
> >> &file_alloc_attr.attr,
> >> &file_fallback_attr.attr,
> >> &file_fallback_charge_attr.attr,
> >> + &split_attr.attr,
> >> + &split_failed_attr.attr,
> >> + &split_deferred_attr.attr,
> >> NULL,
> >> };
> >>
> >> @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> >> XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
> >> struct anon_vma *anon_vma = NULL;
> >> struct address_space *mapping = NULL;
> >> - bool is_thp = folio_test_pmd_mappable(folio);
> >> + int order = folio_order(folio);
> >> int extra_pins, ret;
> >> pgoff_t end;
> >> bool is_hzp;
> >> @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> >> VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
> >> VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
> >>
> >> - if (new_order >= folio_order(folio))
> >> + if (new_order >= order)
> >> return -EINVAL;
> >>
> >> if (folio_test_anon(folio)) {
> >> @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> >> i_mmap_unlock_read(mapping);
> >> out:
> >> xas_destroy(&xas);
> >> - if (is_thp)
> >> + if (order >= HPAGE_PMD_ORDER)
> >> count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
> >> + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
> >> return ret;
> >> }
> >>
> >> @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
> >> #ifdef CONFIG_MEMCG
> >> struct mem_cgroup *memcg = folio_memcg(folio);
> >> #endif
> >> + int order = folio_order(folio);
> >> unsigned long flags;
> >>
> >> /*
> >> * Order 1 folios have no space for a deferred list, but we also
> >> * won't waste much memory by not adding them to the deferred list.
> >> */
> >> - if (folio_order(folio) <= 1)
> >> + if (order <= 1)
> >> return;
> >>
> >> /*
> >> @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
> >>
> >> spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
> >> if (list_empty(&folio->_deferred_list)) {
> >> - if (folio_test_pmd_mappable(folio))
> >> + if (order >= HPAGE_PMD_ORDER)
> >> count_vm_event(THP_DEFERRED_SPLIT_PAGE);
> >> + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
> >> list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
> >> ds_queue->split_queue_len++;
> >> #ifdef CONFIG_MEMCG
> >> --
> >> 2.45.2
> >>
Hi Barry,
Thanks for taking time to review!
On Mon, Jul 1, 2024 at 8:02 AM Barry Song <21cnbao@gmail.com> wrote:
>
> On Sat, Jun 29, 2024 at 1:09 AM Lance Yang <ioworker0@gmail.com> wrote:
> >
> > Currently, the split counters in THP statistics no longer include
> > PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
> > counters to monitor the frequency of mTHP splits. This will help developers
> > better analyze and optimize system performance.
> >
> > /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
> > split
> > split_failed
> > split_deferred
> >
> > Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
> > Signed-off-by: Lance Yang <ioworker0@gmail.com>
>
> Personally, I'm not convinced that using a temporary variable order
> makes the code
> more readable. Functions like folio_test_pmd_mappable() seem more readable to
Agreed. Using functions like folio_test_pmd_mappable() is more readable
for THP checks.
> me. In any case, it's a minor issue.
I'd like to hear other opinions as well ;)
>
> Acked-by: Barry Song <baohua@kernel.org>
Thanks again for your time!
Lance
>
> > ---
> > include/linux/huge_mm.h | 3 +++
> > mm/huge_memory.c | 19 ++++++++++++++-----
> > 2 files changed, 17 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> > index 212cca384d7e..cee3c5da8f0e 100644
> > --- a/include/linux/huge_mm.h
> > +++ b/include/linux/huge_mm.h
> > @@ -284,6 +284,9 @@ enum mthp_stat_item {
> > MTHP_STAT_FILE_ALLOC,
> > MTHP_STAT_FILE_FALLBACK,
> > MTHP_STAT_FILE_FALLBACK_CHARGE,
> > + MTHP_STAT_SPLIT,
> > + MTHP_STAT_SPLIT_FAILED,
> > + MTHP_STAT_SPLIT_DEFERRED,
> > __MTHP_STAT_COUNT
> > };
> >
> > diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> > index c7ce28f6b7f3..a633206375af 100644
> > --- a/mm/huge_memory.c
> > +++ b/mm/huge_memory.c
> > @@ -559,6 +559,9 @@ 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_CHARGE);
> > +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
> > +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
> > +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
> >
> > static struct attribute *stats_attrs[] = {
> > &anon_fault_alloc_attr.attr,
> > @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = {
> > &file_alloc_attr.attr,
> > &file_fallback_attr.attr,
> > &file_fallback_charge_attr.attr,
> > + &split_attr.attr,
> > + &split_failed_attr.attr,
> > + &split_deferred_attr.attr,
> > NULL,
> > };
> >
> > @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
> > struct anon_vma *anon_vma = NULL;
> > struct address_space *mapping = NULL;
> > - bool is_thp = folio_test_pmd_mappable(folio);
> > + int order = folio_order(folio);
> > int extra_pins, ret;
> > pgoff_t end;
> > bool is_hzp;
> > @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
> > VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
> >
> > - if (new_order >= folio_order(folio))
> > + if (new_order >= order)
> > return -EINVAL;
> >
> > if (folio_test_anon(folio)) {
> > @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > i_mmap_unlock_read(mapping);
> > out:
> > xas_destroy(&xas);
> > - if (is_thp)
> > + if (order >= HPAGE_PMD_ORDER)
> > count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
> > + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
> > return ret;
> > }
> >
> > @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio)
> > #ifdef CONFIG_MEMCG
> > struct mem_cgroup *memcg = folio_memcg(folio);
> > #endif
> > + int order = folio_order(folio);
> > unsigned long flags;
> >
> > /*
> > * Order 1 folios have no space for a deferred list, but we also
> > * won't waste much memory by not adding them to the deferred list.
> > */
> > - if (folio_order(folio) <= 1)
> > + if (order <= 1)
> > return;
> >
> > /*
> > @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio)
> >
> > spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
> > if (list_empty(&folio->_deferred_list)) {
> > - if (folio_test_pmd_mappable(folio))
> > + if (order >= HPAGE_PMD_ORDER)
> > count_vm_event(THP_DEFERRED_SPLIT_PAGE);
> > + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
> > list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
> > ds_queue->split_queue_len++;
> > #ifdef CONFIG_MEMCG
> > --
> > 2.45.2
> >
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