[v4,1/2] mm: pass page count and reserved to __init_single_page

Message ID 20230928083302.386202-2-yajun.deng@linux.dev
State New
Headers
Series mm: Don't set and reset page count in MEMINIT_EARLY |

Commit Message

Yajun Deng Sept. 28, 2023, 8:33 a.m. UTC
  When we init a single page, we need to mark that page reserved when it
is reserved. And some pages need to reset page count, such as compound
pages.

Introduce enum init_page_flags, the caller will init page count and mark
page reserved by passing INIT_PAGE_COUNT and INIT_PAGE_RESERVED.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
v4: move the changes of __init_zone_device_page().
v3: Introduce enum init_page_flags.
v2: Introduce INIT_PAGE_COUNT and INIT_PAGE_RESERVED.
v1: https://lore.kernel.org/all/20230922070923.355656-1-yajun.deng@linux.dev/
---
 mm/hugetlb.c  |  2 +-
 mm/internal.h |  8 +++++++-
 mm/mm_init.c  | 24 +++++++++++++-----------
 3 files changed, 21 insertions(+), 13 deletions(-)
  

Comments

Mike Rapoport Sept. 29, 2023, 8:19 a.m. UTC | #1
On Thu, Sep 28, 2023 at 04:33:01PM +0800, Yajun Deng wrote:
> Subject: mm: pass page count and reserved to __init_single_page

We add pass flags that tell __init_single_page() how to initialize page
count and PG_Reserved, I think a better subject would be:

mm: allow optional initialization of page count and PG_reserved flag

> When we init a single page, we need to mark that page reserved when it
> is reserved. And some pages need to reset page count, such as compound
> pages.
>
> Introduce enum init_page_flags, the caller will init page count and mark
> page reserved by passing INIT_PAGE_COUNT and INIT_PAGE_RESERVED.

This does not really describe why the change is needed. How about

__init_single_page() unconditionally resets page count which is unnecessary
for reserved pages. 

To allow skipping page count initialization and marking a page reserved in
one go add flags parameter to __init_single_page().

No functional changes.

> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
> ---
> v4: move the changes of __init_zone_device_page().
> v3: Introduce enum init_page_flags.
> v2: Introduce INIT_PAGE_COUNT and INIT_PAGE_RESERVED.
> v1: https://lore.kernel.org/all/20230922070923.355656-1-yajun.deng@linux.dev/
> ---
>  mm/hugetlb.c  |  2 +-
>  mm/internal.h |  8 +++++++-
>  mm/mm_init.c  | 24 +++++++++++++-----------
>  3 files changed, 21 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index a82dc37669b0..bb9c334a8392 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3196,7 +3196,7 @@ static void __init hugetlb_folio_init_tail_vmemmap(struct folio *folio,
>  	for (pfn = head_pfn + start_page_number; pfn < end_pfn; pfn++) {
>  		struct page *page = pfn_to_page(pfn);
>  
> -		__init_single_page(page, pfn, zone, nid);
> +		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
>  		prep_compound_tail((struct page *)folio, pfn - head_pfn);
>  		ret = page_ref_freeze(page, 1);
>  		VM_BUG_ON(!ret);
> diff --git a/mm/internal.h b/mm/internal.h
> index d7916f1e9e98..449891ad7fdb 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -1209,8 +1209,14 @@ struct vma_prepare {
>  	struct vm_area_struct *remove2;
>  };
>  
> +enum init_page_flags {

enum page_init_flags please

> +	INIT_PAGE_COUNT    = (1 << 0),
> +	INIT_PAGE_RESERVED = (1 << 1),
> +};
> +
>  void __meminit __init_single_page(struct page *page, unsigned long pfn,
> -				unsigned long zone, int nid);
> +				  unsigned long zone, int nid,
> +				  enum init_page_flags flags);
>  
>  /* shrinker related functions */
>  unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 06a72c223bce..9716c8a7ade9 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -557,11 +557,11 @@ static void __init find_zone_movable_pfns_for_nodes(void)
>  }
>  
>  void __meminit __init_single_page(struct page *page, unsigned long pfn,
> -				unsigned long zone, int nid)
> +				  unsigned long zone, int nid,
> +				  enum init_page_flags flags)
>  {
>  	mm_zero_struct_page(page);
>  	set_page_links(page, zone, nid, pfn);
> -	init_page_count(page);
>  	page_mapcount_reset(page);
>  	page_cpupid_reset_last(page);
>  	page_kasan_tag_reset(page);
> @@ -572,6 +572,10 @@ void __meminit __init_single_page(struct page *page, unsigned long pfn,
>  	if (!is_highmem_idx(zone))
>  		set_page_address(page, __va(pfn << PAGE_SHIFT));
>  #endif
> +	if (flags & INIT_PAGE_COUNT)
> +		init_page_count(page);
> +	if (flags & INIT_PAGE_RESERVED)
> +		__SetPageReserved(page);
>  }
>  
>  #ifdef CONFIG_NUMA
> @@ -714,7 +718,7 @@ static void __meminit init_reserved_page(unsigned long pfn, int nid)
>  		if (zone_spans_pfn(zone, pfn))
>  			break;
>  	}
> -	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
> +	__init_single_page(pfn_to_page(pfn), pfn, zid, nid, INIT_PAGE_COUNT);

There is __SetPageReserved call a few lines below, it can be folded here.

>  }
>  #else
>  static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
> @@ -821,8 +825,8 @@ static void __init init_unavailable_range(unsigned long spfn,
>  			pfn = pageblock_end_pfn(pfn) - 1;
>  			continue;
>  		}
> -		__init_single_page(pfn_to_page(pfn), pfn, zone, node);
> -		__SetPageReserved(pfn_to_page(pfn));
> +		__init_single_page(pfn_to_page(pfn), pfn, zone, node,
> +				   INIT_PAGE_COUNT | INIT_PAGE_RESERVED);
>  		pgcnt++;
>  	}
>  
> @@ -884,7 +888,7 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone
>  		}
>  
>  		page = pfn_to_page(pfn);
> -		__init_single_page(page, pfn, zone, nid);
> +		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
>  		if (context == MEMINIT_HOTPLUG)
>  			__SetPageReserved(page);
>  
> @@ -967,9 +971,6 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
>  					  unsigned long zone_idx, int nid,
>  					  struct dev_pagemap *pgmap)
>  {
> -
> -	__init_single_page(page, pfn, zone_idx, nid);
> -
>  	/*
>  	 * Mark page reserved as it will need to wait for onlining
>  	 * phase for it to be fully associated with a zone.
> @@ -977,7 +978,8 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
>  	 * We can use the non-atomic __set_bit operation for setting
>  	 * the flag as we are still initializing the pages.
>  	 */
> -	__SetPageReserved(page);
> +	__init_single_page(page, pfn, zone_idx, nid,
> +			   INIT_PAGE_COUNT | INIT_PAGE_RESERVED);
>  
>  	/*
>  	 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
> @@ -2058,7 +2060,7 @@ static unsigned long  __init deferred_init_pages(struct zone *zone,
>  		} else {
>  			page++;
>  		}
> -		__init_single_page(page, pfn, zid, nid);
> +		__init_single_page(page, pfn, zid, nid, INIT_PAGE_COUNT);
>  		nr_pages++;
>  	}
>  	return (nr_pages);
> -- 
> 2.25.1
>
  
Yajun Deng Sept. 29, 2023, 9:37 a.m. UTC | #2
On 2023/9/29 16:19, Mike Rapoport wrote:
> On Thu, Sep 28, 2023 at 04:33:01PM +0800, Yajun Deng wrote:
>> Subject: mm: pass page count and reserved to __init_single_page
> We add pass flags that tell __init_single_page() how to initialize page
> count and PG_Reserved, I think a better subject would be:
>
> mm: allow optional initialization of page count and PG_reserved flag
Okay.
>> When we init a single page, we need to mark that page reserved when it
>> is reserved. And some pages need to reset page count, such as compound
>> pages.
>>
>> Introduce enum init_page_flags, the caller will init page count and mark
>> page reserved by passing INIT_PAGE_COUNT and INIT_PAGE_RESERVED.
> This does not really describe why the change is needed. How about
>
> __init_single_page() unconditionally resets page count which is unnecessary
> for reserved pages.
>
> To allow skipping page count initialization and marking a page reserved in
> one go add flags parameter to __init_single_page().
>
> No functional changes.
Okay.
>> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
>> ---
>> v4: move the changes of __init_zone_device_page().
>> v3: Introduce enum init_page_flags.
>> v2: Introduce INIT_PAGE_COUNT and INIT_PAGE_RESERVED.
>> v1: https://lore.kernel.org/all/20230922070923.355656-1-yajun.deng@linux.dev/
>> ---
>>   mm/hugetlb.c  |  2 +-
>>   mm/internal.h |  8 +++++++-
>>   mm/mm_init.c  | 24 +++++++++++++-----------
>>   3 files changed, 21 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
>> index a82dc37669b0..bb9c334a8392 100644
>> --- a/mm/hugetlb.c
>> +++ b/mm/hugetlb.c
>> @@ -3196,7 +3196,7 @@ static void __init hugetlb_folio_init_tail_vmemmap(struct folio *folio,
>>   	for (pfn = head_pfn + start_page_number; pfn < end_pfn; pfn++) {
>>   		struct page *page = pfn_to_page(pfn);
>>   
>> -		__init_single_page(page, pfn, zone, nid);
>> +		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
>>   		prep_compound_tail((struct page *)folio, pfn - head_pfn);
>>   		ret = page_ref_freeze(page, 1);
>>   		VM_BUG_ON(!ret);
>> diff --git a/mm/internal.h b/mm/internal.h
>> index d7916f1e9e98..449891ad7fdb 100644
>> --- a/mm/internal.h
>> +++ b/mm/internal.h
>> @@ -1209,8 +1209,14 @@ struct vma_prepare {
>>   	struct vm_area_struct *remove2;
>>   };
>>   
>> +enum init_page_flags {
> enum page_init_flags please
Okay.
>> +	INIT_PAGE_COUNT    = (1 << 0),
>> +	INIT_PAGE_RESERVED = (1 << 1),
>> +};
>> +
>>   void __meminit __init_single_page(struct page *page, unsigned long pfn,
>> -				unsigned long zone, int nid);
>> +				  unsigned long zone, int nid,
>> +				  enum init_page_flags flags);
>>   
>>   /* shrinker related functions */
>>   unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
>> diff --git a/mm/mm_init.c b/mm/mm_init.c
>> index 06a72c223bce..9716c8a7ade9 100644
>> --- a/mm/mm_init.c
>> +++ b/mm/mm_init.c
>> @@ -557,11 +557,11 @@ static void __init find_zone_movable_pfns_for_nodes(void)
>>   }
>>   
>>   void __meminit __init_single_page(struct page *page, unsigned long pfn,
>> -				unsigned long zone, int nid)
>> +				  unsigned long zone, int nid,
>> +				  enum init_page_flags flags)
>>   {
>>   	mm_zero_struct_page(page);
>>   	set_page_links(page, zone, nid, pfn);
>> -	init_page_count(page);
>>   	page_mapcount_reset(page);
>>   	page_cpupid_reset_last(page);
>>   	page_kasan_tag_reset(page);
>> @@ -572,6 +572,10 @@ void __meminit __init_single_page(struct page *page, unsigned long pfn,
>>   	if (!is_highmem_idx(zone))
>>   		set_page_address(page, __va(pfn << PAGE_SHIFT));
>>   #endif
>> +	if (flags & INIT_PAGE_COUNT)
>> +		init_page_count(page);
>> +	if (flags & INIT_PAGE_RESERVED)
>> +		__SetPageReserved(page);
>>   }
>>   
>>   #ifdef CONFIG_NUMA
>> @@ -714,7 +718,7 @@ static void __meminit init_reserved_page(unsigned long pfn, int nid)
>>   		if (zone_spans_pfn(zone, pfn))
>>   			break;
>>   	}
>> -	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
>> +	__init_single_page(pfn_to_page(pfn), pfn, zid, nid, INIT_PAGE_COUNT);
> There is __SetPageReserved call a few lines below, it can be folded here.
>
No, There is a #ifdef in front of it. If so, I need to add 
__SetPageReserved to another init_reserved_page().

And there is an return before __init_single_page.
I will change INIT_PAGE_COUNT to 0 in next patch.

>>   }
>>   #else
>>   static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
>> @@ -821,8 +825,8 @@ static void __init init_unavailable_range(unsigned long spfn,
>>   			pfn = pageblock_end_pfn(pfn) - 1;
>>   			continue;
>>   		}
>> -		__init_single_page(pfn_to_page(pfn), pfn, zone, node);
>> -		__SetPageReserved(pfn_to_page(pfn));
>> +		__init_single_page(pfn_to_page(pfn), pfn, zone, node,
>> +				   INIT_PAGE_COUNT | INIT_PAGE_RESERVED);
>>   		pgcnt++;
>>   	}
>>   
>> @@ -884,7 +888,7 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone
>>   		}
>>   
>>   		page = pfn_to_page(pfn);
>> -		__init_single_page(page, pfn, zone, nid);
>> +		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
>>   		if (context == MEMINIT_HOTPLUG)
>>   			__SetPageReserved(page);
>>   
>> @@ -967,9 +971,6 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
>>   					  unsigned long zone_idx, int nid,
>>   					  struct dev_pagemap *pgmap)
>>   {
>> -
>> -	__init_single_page(page, pfn, zone_idx, nid);
>> -
>>   	/*
>>   	 * Mark page reserved as it will need to wait for onlining
>>   	 * phase for it to be fully associated with a zone.
>> @@ -977,7 +978,8 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
>>   	 * We can use the non-atomic __set_bit operation for setting
>>   	 * the flag as we are still initializing the pages.
>>   	 */
>> -	__SetPageReserved(page);
>> +	__init_single_page(page, pfn, zone_idx, nid,
>> +			   INIT_PAGE_COUNT | INIT_PAGE_RESERVED);
>>   
>>   	/*
>>   	 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
>> @@ -2058,7 +2060,7 @@ static unsigned long  __init deferred_init_pages(struct zone *zone,
>>   		} else {
>>   			page++;
>>   		}
>> -		__init_single_page(page, pfn, zid, nid);
>> +		__init_single_page(page, pfn, zid, nid, INIT_PAGE_COUNT);
>>   		nr_pages++;
>>   	}
>>   	return (nr_pages);
>> -- 
>> 2.25.1
>>
  

Patch

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a82dc37669b0..bb9c334a8392 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3196,7 +3196,7 @@  static void __init hugetlb_folio_init_tail_vmemmap(struct folio *folio,
 	for (pfn = head_pfn + start_page_number; pfn < end_pfn; pfn++) {
 		struct page *page = pfn_to_page(pfn);
 
-		__init_single_page(page, pfn, zone, nid);
+		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
 		prep_compound_tail((struct page *)folio, pfn - head_pfn);
 		ret = page_ref_freeze(page, 1);
 		VM_BUG_ON(!ret);
diff --git a/mm/internal.h b/mm/internal.h
index d7916f1e9e98..449891ad7fdb 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1209,8 +1209,14 @@  struct vma_prepare {
 	struct vm_area_struct *remove2;
 };
 
+enum init_page_flags {
+	INIT_PAGE_COUNT    = (1 << 0),
+	INIT_PAGE_RESERVED = (1 << 1),
+};
+
 void __meminit __init_single_page(struct page *page, unsigned long pfn,
-				unsigned long zone, int nid);
+				  unsigned long zone, int nid,
+				  enum init_page_flags flags);
 
 /* shrinker related functions */
 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 06a72c223bce..9716c8a7ade9 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -557,11 +557,11 @@  static void __init find_zone_movable_pfns_for_nodes(void)
 }
 
 void __meminit __init_single_page(struct page *page, unsigned long pfn,
-				unsigned long zone, int nid)
+				  unsigned long zone, int nid,
+				  enum init_page_flags flags)
 {
 	mm_zero_struct_page(page);
 	set_page_links(page, zone, nid, pfn);
-	init_page_count(page);
 	page_mapcount_reset(page);
 	page_cpupid_reset_last(page);
 	page_kasan_tag_reset(page);
@@ -572,6 +572,10 @@  void __meminit __init_single_page(struct page *page, unsigned long pfn,
 	if (!is_highmem_idx(zone))
 		set_page_address(page, __va(pfn << PAGE_SHIFT));
 #endif
+	if (flags & INIT_PAGE_COUNT)
+		init_page_count(page);
+	if (flags & INIT_PAGE_RESERVED)
+		__SetPageReserved(page);
 }
 
 #ifdef CONFIG_NUMA
@@ -714,7 +718,7 @@  static void __meminit init_reserved_page(unsigned long pfn, int nid)
 		if (zone_spans_pfn(zone, pfn))
 			break;
 	}
-	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
+	__init_single_page(pfn_to_page(pfn), pfn, zid, nid, INIT_PAGE_COUNT);
 }
 #else
 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
@@ -821,8 +825,8 @@  static void __init init_unavailable_range(unsigned long spfn,
 			pfn = pageblock_end_pfn(pfn) - 1;
 			continue;
 		}
-		__init_single_page(pfn_to_page(pfn), pfn, zone, node);
-		__SetPageReserved(pfn_to_page(pfn));
+		__init_single_page(pfn_to_page(pfn), pfn, zone, node,
+				   INIT_PAGE_COUNT | INIT_PAGE_RESERVED);
 		pgcnt++;
 	}
 
@@ -884,7 +888,7 @@  void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone
 		}
 
 		page = pfn_to_page(pfn);
-		__init_single_page(page, pfn, zone, nid);
+		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
 		if (context == MEMINIT_HOTPLUG)
 			__SetPageReserved(page);
 
@@ -967,9 +971,6 @@  static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
 					  unsigned long zone_idx, int nid,
 					  struct dev_pagemap *pgmap)
 {
-
-	__init_single_page(page, pfn, zone_idx, nid);
-
 	/*
 	 * Mark page reserved as it will need to wait for onlining
 	 * phase for it to be fully associated with a zone.
@@ -977,7 +978,8 @@  static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
 	 * We can use the non-atomic __set_bit operation for setting
 	 * the flag as we are still initializing the pages.
 	 */
-	__SetPageReserved(page);
+	__init_single_page(page, pfn, zone_idx, nid,
+			   INIT_PAGE_COUNT | INIT_PAGE_RESERVED);
 
 	/*
 	 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
@@ -2058,7 +2060,7 @@  static unsigned long  __init deferred_init_pages(struct zone *zone,
 		} else {
 			page++;
 		}
-		__init_single_page(page, pfn, zid, nid);
+		__init_single_page(page, pfn, zid, nid, INIT_PAGE_COUNT);
 		nr_pages++;
 	}
 	return (nr_pages);