[PATCH 16/49] mm/hugetlb: initialize vmemmap optimization in early stage

[Muchun Song]

Move pfn_to_zone() to be available for hugetlb_vmemmap_init_early().
Populate vmemmap HVO in hugetlb_vmemmap_init_early() for bootmem allocated
huge pages.

The zone information is already available in hugetlb_vmemmap_init_early(),
so there is no need to wait for hugetlb_vmemmap_init_late() to access it.
This prepares for the removal of hugetlb_vmemmap_init_late().

Signed-off-by: Muchun Song <songmuchun at bytedance.com>
---
 mm/hugetlb_vmemmap.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 50b7123f3bdd..e25c70453928 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -745,6 +745,20 @@ static bool vmemmap_should_optimize_bootmem_page(struct huge_bootmem_page *m)
 	return true;
 }
 
+static struct zone *pfn_to_zone(unsigned nid, unsigned long pfn)
+{
+	struct zone *zone;
+	enum zone_type zone_type;
+
+	for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
+		zone = &NODE_DATA(nid)->node_zones[zone_type];
+		if (zone_spans_pfn(zone, pfn))
+			return zone;
+	}
+
+	return NULL;
+}
+
 /*
  * Initialize memmap section for a gigantic page, HVO-style.
  */
@@ -752,6 +766,7 @@ void __init hugetlb_vmemmap_init_early(int nid)
 {
 	unsigned long psize, paddr, section_size;
 	unsigned long ns, i, pnum, pfn, nr_pages;
+	unsigned long start, end;
 	struct huge_bootmem_page *m = NULL;
 	void *map;
 
@@ -761,6 +776,8 @@ void __init hugetlb_vmemmap_init_early(int nid)
 	section_size = (1UL << PA_SECTION_SHIFT);
 
 	list_for_each_entry(m, &huge_boot_pages[nid], list) {
+		struct zone *zone;
+
 		if (!vmemmap_should_optimize_bootmem_page(m))
 			continue;
 
@@ -769,6 +786,13 @@ void __init hugetlb_vmemmap_init_early(int nid)
 		paddr = virt_to_phys(m);
 		pfn = PHYS_PFN(paddr);
 		map = pfn_to_page(pfn);
+		start = (unsigned long)map;
+		end = start + nr_pages * sizeof(struct page);
+		zone = pfn_to_zone(nid, pfn);
+
+		BUG_ON(vmemmap_populate_hvo(start, end, huge_page_order(m->hstate),
+					    zone, HUGETLB_VMEMMAP_RESERVE_SIZE));
+		memmap_boot_pages_add(HUGETLB_VMEMMAP_RESERVE_SIZE / PAGE_SIZE);
 
 		pnum = pfn_to_section_nr(pfn);
 		ns = psize / section_size;
@@ -784,20 +808,6 @@ void __init hugetlb_vmemmap_init_early(int nid)
 	}
 }
 
-static struct zone *pfn_to_zone(unsigned nid, unsigned long pfn)
-{
-	struct zone *zone;
-	enum zone_type zone_type;
-
-	for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
-		zone = &NODE_DATA(nid)->node_zones[zone_type];
-		if (zone_spans_pfn(zone, pfn))
-			return zone;
-	}
-
-	return NULL;
-}
-
 void __init hugetlb_vmemmap_init_late(int nid)
 {
 	struct huge_bootmem_page *m, *tm;
-- 
2.20.1