diff mbox series

[1/4] mm: pass set_count and set_reserved to __init_single_page

Message ID 20230922070923.355656-2-yajun.deng@linux.dev
State New
Headers
Series mm: Don't set and reset page count in MEMINIT_EARLY |

Commit Message

Yajun Deng Sept. 22, 2023, 7:09 a.m. UTC 
  When we init a single page, we need to mark this page reserved if it
does. And somes page may not need to set page count, such as compound
pages.

Pass set_count and set_reserved to __init_single_page, let the caller
decide if it needs to set page count or mark page reserved.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
 mm/hugetlb.c  |  2 +-
 mm/internal.h |  3 ++-
 mm/mm_init.c  | 30 ++++++++++++++++--------------
 3 files changed, 19 insertions(+), 16 deletions(-)

Comments

Yajun Deng Sept. 25, 2023, 3:23 a.m. UTC | #1 
On 2023/9/22 16:08, Mike Rapoport wrote:
> On Fri, Sep 22, 2023 at 09:48:59AM +0200, David Hildenbrand wrote:
>> On 22.09.23 09:47, Matthew Wilcox wrote:
>>> On Fri, Sep 22, 2023 at 03:09:20PM +0800, Yajun Deng wrote:
>>>> -		__init_single_page(page, pfn, zone, nid);
>>>> +		__init_single_page(page, pfn, zone, nid, true, false);
>>> So Linus has just had a big rant about not doing bool flags to
>>> functions.  And in particular _multiple_ bool flags to functions.
>>>
>>> ie this should be:
>>>
>>> #define INIT_PAGE_COUNT		(1 << 0)
>>> #define INIT_PAGE_RESERVED	(1 << 1)
>>>
>>> 		__init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT);
>>>
>>> or something similar.
>>>
>>> I have no judgement on the merits of this patch so far.  Do you have
>>> performance numbers for each of these patches?  Some of them seem quite
>>> unlikely to actually help, at least on a machine which is constrained
>>> by cacheline fetches.
>> The last patch contains
>>
>> before:
>> node 0 deferred pages initialised in 78ms
>>
>> after:
>> node 0 deferred pages initialised in 72ms
>>
>> Not earth-shattering :D Maybe with much bigger machines relevant?
> Patch 3 contains
>
> The following data was tested on an x86 machine with 190GB of RAM.
>
> before:
> free_low_memory_core_early()    342ms
>
> after:
> free_low_memory_core_early()    286ms
>
> Which is more impressive, but still I'm not convinced that it's worth the
> added complexity and potential subtle bugs.
>
I will send v2.  It will be simpler and safer.
>> -- 
>> Cheers,
>>
>> David / dhildenb
>>
diff mbox series

Patch

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e2123d1bb4a2..4f91e47430ce 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, true, false);
 		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 7a961d12b088..8bded7f98493 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1210,7 +1210,8 @@  struct vma_prepare {
 };
 
 void __meminit __init_single_page(struct page *page, unsigned long pfn,
-				unsigned long zone, int nid);
+				  unsigned long zone, int nid, bool set_count,
+				  bool set_reserved);
 
 /* 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..c40042098a82 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -557,11 +557,13 @@  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, bool set_count,
+				  bool set_reserved)
 {
 	mm_zero_struct_page(page);
 	set_page_links(page, zone, nid, pfn);
-	init_page_count(page);
+	if (set_count)
+		init_page_count(page);
 	page_mapcount_reset(page);
 	page_cpupid_reset_last(page);
 	page_kasan_tag_reset(page);
@@ -572,6 +574,8 @@  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 (set_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, true, false);
 }
 #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,
+				   true, true);
 		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, true, false);
 		if (context == MEMINIT_HOTPLUG)
 			__SetPageReserved(page);
 
@@ -965,11 +969,9 @@  static void __init memmap_init(void)
 #ifdef CONFIG_ZONE_DEVICE
 static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
 					  unsigned long zone_idx, int nid,
-					  struct dev_pagemap *pgmap)
+					  struct dev_pagemap *pgmap,
+					  bool set_count)
 {
-
-	__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 +979,7 @@  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, set_count, true);
 
 	/*
 	 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
@@ -1041,7 +1043,7 @@  static void __ref memmap_init_compound(struct page *head,
 	for (pfn = head_pfn + 1; pfn < end_pfn; pfn++) {
 		struct page *page = pfn_to_page(pfn);
 
-		__init_zone_device_page(page, pfn, zone_idx, nid, pgmap);
+		__init_zone_device_page(page, pfn, zone_idx, nid, pgmap, false);
 		prep_compound_tail(head, pfn - head_pfn);
 		set_page_count(page, 0);
 
@@ -1084,7 +1086,7 @@  void __ref memmap_init_zone_device(struct zone *zone,
 	for (pfn = start_pfn; pfn < end_pfn; pfn += pfns_per_compound) {
 		struct page *page = pfn_to_page(pfn);
 
-		__init_zone_device_page(page, pfn, zone_idx, nid, pgmap);
+		__init_zone_device_page(page, pfn, zone_idx, nid, pgmap, true);
 
 		if (pfns_per_compound == 1)
 			continue;
@@ -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, true, false);
 		nr_pages++;
 	}
 	return (nr_pages);