* [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page()
@ 2025-10-04 9:25 Wei Yang
2025-10-04 14:26 ` Dev Jain
2025-10-05 1:48 ` Matthew Wilcox
0 siblings, 2 replies; 6+ messages in thread
From: Wei Yang @ 2025-10-04 9:25 UTC (permalink / raw)
To: akpm, david, lorenzo.stoakes, ziy, baolin.wang, Liam.Howlett,
npache, ryan.roberts, dev.jain, baohua, lance.yang
Cc: linux-mm, Wei Yang
Unify the process to install pmd folio.
No functional change is intended.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
include/linux/huge_mm.h | 6 ++++++
mm/huge_memory.c | 18 ++++++++++--------
mm/khugepaged.c | 9 +--------
3 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index e3ed008a076a..becfba48d17e 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -539,6 +539,8 @@ void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmd, bool freeze);
bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmdp, struct folio *folio);
+void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
+ struct vm_area_struct *vma, unsigned long haddr, bool in_pf);
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
@@ -629,6 +631,10 @@ static inline bool unmap_huge_pmd_locked(struct vm_area_struct *vma,
return false;
}
+void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
+ struct vm_area_struct *vma, unsigned long haddr, bool in_pf)
+{}
+
#define split_huge_pud(__vma, __pmd, __address) \
do { } while (0)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f13de93637bf..bfe38ca60a10 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1217,8 +1217,8 @@ static struct folio *vma_alloc_anon_folio_pmd(struct vm_area_struct *vma,
return folio;
}
-static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
- struct vm_area_struct *vma, unsigned long haddr)
+void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
+ struct vm_area_struct *vma, unsigned long haddr, bool in_pf)
{
pmd_t entry;
@@ -1228,11 +1228,13 @@ static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
folio_add_lru_vma(folio, vma);
set_pmd_at(vma->vm_mm, haddr, pmd, entry);
update_mmu_cache_pmd(vma, haddr, pmd);
- add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
- count_vm_event(THP_FAULT_ALLOC);
- count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
- count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
deferred_split_folio(folio, false);
+ if (in_pf) {
+ add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
+ count_vm_event(THP_FAULT_ALLOC);
+ count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
+ count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
+ }
}
static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf)
@@ -1271,7 +1273,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf)
return ret;
}
pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);
- map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);
+ map_anon_folio_pmd(folio, vmf->pmd, vma, haddr, true);
mm_inc_nr_ptes(vma->vm_mm);
spin_unlock(vmf->ptl);
}
@@ -1877,7 +1879,7 @@ static vm_fault_t do_huge_zero_wp_pmd(struct vm_fault *vmf)
if (ret)
goto release;
(void)pmdp_huge_clear_flush(vma, haddr, vmf->pmd);
- map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);
+ map_anon_folio_pmd(folio, vmf->pmd, vma, haddr, true);
goto unlock;
release:
folio_put(folio);
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index f4f57ba69d72..cd187d10dee6 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1224,17 +1224,10 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
__folio_mark_uptodate(folio);
pgtable = pmd_pgtable(_pmd);
- _pmd = folio_mk_pmd(folio, vma->vm_page_prot);
- _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
-
spin_lock(pmd_ptl);
BUG_ON(!pmd_none(*pmd));
- folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE);
- folio_add_lru_vma(folio, vma);
pgtable_trans_huge_deposit(mm, pmd, pgtable);
- set_pmd_at(mm, address, pmd, _pmd);
- update_mmu_cache_pmd(vma, address, pmd);
- deferred_split_folio(folio, false);
+ map_anon_folio_pmd(folio, pmd, vma, address, false);
spin_unlock(pmd_ptl);
folio = NULL;
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page()
2025-10-04 9:25 [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page() Wei Yang
@ 2025-10-04 14:26 ` Dev Jain
2025-10-05 0:04 ` Wei Yang
2025-10-05 1:48 ` Matthew Wilcox
1 sibling, 1 reply; 6+ messages in thread
From: Dev Jain @ 2025-10-04 14:26 UTC (permalink / raw)
To: Wei Yang, akpm, david, lorenzo.stoakes, ziy, baolin.wang,
Liam.Howlett, npache, ryan.roberts, baohua, lance.yang
Cc: linux-mm
On 04/10/25 2:55 pm, Wei Yang wrote:
> Unify the process to install pmd folio.
>
> No functional change is intended.
>
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Base commit on which this patch applies?
> ---
> include/linux/huge_mm.h | 6 ++++++
> mm/huge_memory.c | 18 ++++++++++--------
> mm/khugepaged.c | 9 +--------
> 3 files changed, 17 insertions(+), 16 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index e3ed008a076a..becfba48d17e 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -539,6 +539,8 @@ void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address,
> pmd_t *pmd, bool freeze);
> bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
> pmd_t *pmdp, struct folio *folio);
> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf);
>
> #else /* CONFIG_TRANSPARENT_HUGEPAGE */
>
> @@ -629,6 +631,10 @@ static inline bool unmap_huge_pmd_locked(struct vm_area_struct *vma,
> return false;
> }
>
> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf)
> +{}
> +
> #define split_huge_pud(__vma, __pmd, __address) \
> do { } while (0)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index f13de93637bf..bfe38ca60a10 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1217,8 +1217,8 @@ static struct folio *vma_alloc_anon_folio_pmd(struct vm_area_struct *vma,
> return folio;
> }
>
> -static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> - struct vm_area_struct *vma, unsigned long haddr)
> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf)
> {
> pmd_t entry;
>
> @@ -1228,11 +1228,13 @@ static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> folio_add_lru_vma(folio, vma);
> set_pmd_at(vma->vm_mm, haddr, pmd, entry);
> update_mmu_cache_pmd(vma, haddr, pmd);
> - add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
> - count_vm_event(THP_FAULT_ALLOC);
> - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
> - count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
> deferred_split_folio(folio, false);
> + if (in_pf) {
> + add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
> + count_vm_event(THP_FAULT_ALLOC);
> + count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
> + count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
> + }
> }
>
> static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> @@ -1271,7 +1273,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> return ret;
> }
> pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);
> - map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);
> + map_anon_folio_pmd(folio, vmf->pmd, vma, haddr, true);
> mm_inc_nr_ptes(vma->vm_mm);
> spin_unlock(vmf->ptl);
> }
> @@ -1877,7 +1879,7 @@ static vm_fault_t do_huge_zero_wp_pmd(struct vm_fault *vmf)
> if (ret)
> goto release;
> (void)pmdp_huge_clear_flush(vma, haddr, vmf->pmd);
> - map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);
> + map_anon_folio_pmd(folio, vmf->pmd, vma, haddr, true);
> goto unlock;
> release:
> folio_put(folio);
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index f4f57ba69d72..cd187d10dee6 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1224,17 +1224,10 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
> __folio_mark_uptodate(folio);
> pgtable = pmd_pgtable(_pmd);
>
> - _pmd = folio_mk_pmd(folio, vma->vm_page_prot);
> - _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
> -
> spin_lock(pmd_ptl);
> BUG_ON(!pmd_none(*pmd));
> - folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE);
> - folio_add_lru_vma(folio, vma);
> pgtable_trans_huge_deposit(mm, pmd, pgtable);
> - set_pmd_at(mm, address, pmd, _pmd);
> - update_mmu_cache_pmd(vma, address, pmd);
> - deferred_split_folio(folio, false);
> + map_anon_folio_pmd(folio, pmd, vma, address, false);
> spin_unlock(pmd_ptl);
>
> folio = NULL;
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page()
2025-10-04 14:26 ` Dev Jain
@ 2025-10-05 0:04 ` Wei Yang
2025-10-05 0:09 ` Wei Yang
0 siblings, 1 reply; 6+ messages in thread
From: Wei Yang @ 2025-10-05 0:04 UTC (permalink / raw)
To: Dev Jain
Cc: Wei Yang, akpm, david, lorenzo.stoakes, ziy, baolin.wang,
Liam.Howlett, npache, ryan.roberts, baohua, lance.yang, linux-mm
On Sat, Oct 04, 2025 at 07:56:48PM +0530, Dev Jain wrote:
>
>On 04/10/25 2:55 pm, Wei Yang wrote:
>> Unify the process to install pmd folio.
>>
>> No functional change is intended.
>>
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>
>Base commit on which this patch applies?
>
The base commit is
696ef26cfef2 2025-10-03 mm: redefine VM_* flag constants with BIT()
on latest akpm/mm-new branch.
--
Wei Yang
Help you, Help me
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page()
2025-10-05 0:04 ` Wei Yang
@ 2025-10-05 0:09 ` Wei Yang
0 siblings, 0 replies; 6+ messages in thread
From: Wei Yang @ 2025-10-05 0:09 UTC (permalink / raw)
To: Wei Yang
Cc: Dev Jain, akpm, david, lorenzo.stoakes, ziy, baolin.wang,
Liam.Howlett, npache, ryan.roberts, baohua, lance.yang, linux-mm
On Sun, Oct 05, 2025 at 12:04:13AM +0000, Wei Yang wrote:
>On Sat, Oct 04, 2025 at 07:56:48PM +0530, Dev Jain wrote:
>>
>>On 04/10/25 2:55 pm, Wei Yang wrote:
>>> Unify the process to install pmd folio.
>>>
>>> No functional change is intended.
>>>
>>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>>
>>Base commit on which this patch applies?
>>
>
>The base commit is
>
>696ef26cfef2 2025-10-03 mm: redefine VM_* flag constants with BIT()
>
>on latest akpm/mm-new branch.
>
Forget to mention, with this [1] change applied.
[1]: https://lkml.kernel.org/r/20251002013825.20448-1-richard.weiyang@gmail.com
--
Wei Yang
Help you, Help me
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page()
2025-10-04 9:25 [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page() Wei Yang
2025-10-04 14:26 ` Dev Jain
@ 2025-10-05 1:48 ` Matthew Wilcox
2025-10-05 2:55 ` Wei Yang
1 sibling, 1 reply; 6+ messages in thread
From: Matthew Wilcox @ 2025-10-05 1:48 UTC (permalink / raw)
To: Wei Yang
Cc: akpm, david, lorenzo.stoakes, ziy, baolin.wang, Liam.Howlett,
npache, ryan.roberts, dev.jain, baohua, lance.yang, linux-mm
On Sat, Oct 04, 2025 at 09:25:23AM +0000, Wei Yang wrote:
> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf);
It's generally a bad idea to have a 'bool' flag like this because it's
not immediately obvious in the callers what 'true' means.
> -static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> - struct vm_area_struct *vma, unsigned long haddr)
> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf)
> {
> pmd_t entry;
>
> @@ -1228,11 +1228,13 @@ static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
> folio_add_lru_vma(folio, vma);
> set_pmd_at(vma->vm_mm, haddr, pmd, entry);
> update_mmu_cache_pmd(vma, haddr, pmd);
> - add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
> - count_vm_event(THP_FAULT_ALLOC);
> - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
> - count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
> deferred_split_folio(folio, false);
> + if (in_pf) {
> + add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
> + count_vm_event(THP_FAULT_ALLOC);
> + count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
> + count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
> + }
> }
And it's really not necessary here. There's probably better naming
available, but a good pattern to follow here would be:
void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
struct vm_area_struct *vma, unsigned long haddr)
{
...
}
static void map_anon_folio_pmd_pf(struct folio *folio, pmd_t *pmd,
struct vm_area_struct *vma, unsigned long haddr)
{
map_anon_folio_pmd_nopf(folio, pmd, vma, haddr);
add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
count_vm_event(THP_FAULT_ALLOC);
count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
}
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page()
2025-10-05 1:48 ` Matthew Wilcox
@ 2025-10-05 2:55 ` Wei Yang
0 siblings, 0 replies; 6+ messages in thread
From: Wei Yang @ 2025-10-05 2:55 UTC (permalink / raw)
To: Matthew Wilcox
Cc: Wei Yang, akpm, david, lorenzo.stoakes, ziy, baolin.wang,
Liam.Howlett, npache, ryan.roberts, dev.jain, baohua, lance.yang,
linux-mm
On Sun, Oct 05, 2025 at 02:48:25AM +0100, Matthew Wilcox wrote:
>On Sat, Oct 04, 2025 at 09:25:23AM +0000, Wei Yang wrote:
>> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
>> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf);
>
>It's generally a bad idea to have a 'bool' flag like this because it's
>not immediately obvious in the callers what 'true' means.
>
>> -static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
>> - struct vm_area_struct *vma, unsigned long haddr)
>> +void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
>> + struct vm_area_struct *vma, unsigned long haddr, bool in_pf)
>> {
>> pmd_t entry;
>>
>> @@ -1228,11 +1228,13 @@ static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
>> folio_add_lru_vma(folio, vma);
>> set_pmd_at(vma->vm_mm, haddr, pmd, entry);
>> update_mmu_cache_pmd(vma, haddr, pmd);
>> - add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
>> - count_vm_event(THP_FAULT_ALLOC);
>> - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
>> - count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
>> deferred_split_folio(folio, false);
>> + if (in_pf) {
>> + add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
>> + count_vm_event(THP_FAULT_ALLOC);
>> + count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
>> + count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
>> + }
>> }
>
>And it's really not necessary here. There's probably better naming
>available, but a good pattern to follow here would be:
>
>void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
> struct vm_area_struct *vma, unsigned long haddr)
>{
>...
>}
>
>static void map_anon_folio_pmd_pf(struct folio *folio, pmd_t *pmd,
> struct vm_area_struct *vma, unsigned long haddr)
>{
> map_anon_folio_pmd_nopf(folio, pmd, vma, haddr);
> add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
> count_vm_event(THP_FAULT_ALLOC);
> count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
> count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
>}
Thanks for the comment.
Will adjust it.
--
Wei Yang
Help you, Help me
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-10-05 2:55 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-10-04 9:25 [PATCH] mm/khugepaged: use map_anon_folio_pmd() in collapse_huge_page() Wei Yang
2025-10-04 14:26 ` Dev Jain
2025-10-05 0:04 ` Wei Yang
2025-10-05 0:09 ` Wei Yang
2025-10-05 1:48 ` Matthew Wilcox
2025-10-05 2:55 ` Wei Yang
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox