mm: pass nid to reserve_bootmem_region()

early_pfn_to_nid() is called frequently in init_reserved_page(), it
returns the node id of the PFN.  These PFN are probably from the same
memory region, they have the same node id.  It's not necessary to call
early_pfn_to_nid() for each PFN.

Pass nid to reserve_bootmem_region() and drop the call to
early_pfn_to_nid() in init_reserved_page().  Also, set nid on all reserved
pages before doing this, as some reserved memory regions may not be set
nid.

The most beneficial function is memmap_init_reserved_pages() if
CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled.

The following data was tested on an x86 machine with 190GB of RAM.

before:
memmap_init_reserved_pages()  67ms

after:
memmap_init_reserved_pages()  20ms

Link: https://lkml.kernel.org/r/20230619023406.424298-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 21 insertions, 10 deletions

diff --git a/mm/memblock.c b/mm/memblock.c
index da4264528e1e..46739551d4d1 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -2082,19 +2082,30 @@ static void __init memmap_init_reserved_pages(void)
 {
 	struct memblock_region *region;
 	phys_addr_t start, end;
-	u64 i;
+	int nid;
+
+	/*
+	 * set nid on all reserved pages and also treat struct
+	 * pages for the NOMAP regions as PageReserved
+	 */
+	for_each_mem_region(region) {
+		nid = memblock_get_region_node(region);
+		start = region->base;
+		end = start + region->size;
+
+		if (memblock_is_nomap(region))
+			reserve_bootmem_region(start, end, nid);
+
+		memblock_set_node(start, end, &memblock.reserved, nid);
+	}
 
 	/* initialize struct pages for the reserved regions */
-	for_each_reserved_mem_range(i, &start, &end)
-		reserve_bootmem_region(start, end);
+	for_each_reserved_mem_region(region) {
+		nid = memblock_get_region_node(region);
+		start = region->base;
+		end = start + region->size;
 
-	/* and also treat struct pages for the NOMAP regions as PageReserved */
-	for_each_mem_region(region) {
-		if (memblock_is_nomap(region)) {
-			start = region->base;
-			end = start + region->size;
-			reserve_bootmem_region(start, end);
-		}
+		reserve_bootmem_region(start, end, nid);
 	}
 }