[PATCH 2/2] base/node: Use curr_node_memblock_intersect_memory_block to Get Memory Block NID if CONFIG_DEFERRED_STRUCT_PAGE_INIT is Set

From: Donet Tom
Date: Wed Apr 09 2025 - 01:28:53 EST


In the current implementation, when CONFIG_DEFERRED_STRUCT_PAGE_INIT is
set, we iterate over all PFNs in the memory block and use
early_pfn_to_nid to find the NID until a match is found.

This patch we are using curr_node_memblock_intersect_memory_block() to
check if the current node's memblock intersects with the memory block
passed when CONFIG_DEFERRED_STRUCT_PAGE_INIT is set. If an intersection
is found, the memory block is added to the current node.

If CONFIG_DEFERRED_STRUCT_PAGE_INIT is not set, the existing mechanism
for finding the NID will continue to be used.

Signed-off-by: Donet Tom <donettom@xxxxxxxxxxxxx>
---
drivers/base/node.c | 37 +++++++++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index cd13ef287011..5c5dd02b8bdd 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -20,6 +20,8 @@
#include <linux/pm_runtime.h>
#include <linux/swap.h>
#include <linux/slab.h>
+#include <linux/memblock.h>
+

static const struct bus_type node_subsys = {
.name = "node",
@@ -782,16 +784,19 @@ static void do_register_memory_block_under_node(int nid,
ret);
}

-/* register memory section under specified node if it spans that node */
-static int register_mem_block_under_node_early(struct memory_block *mem_blk,
- void *arg)
+static int register_mem_block_early_if_dfer_page_init(struct memory_block *mem_blk,
+ unsigned long start_pfn, unsigned long end_pfn, int nid)
{
- unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
- unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
- unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
- int nid = *(int *)arg;
- unsigned long pfn;

+ if (curr_node_memblock_intersect_memory_block(start_pfn, end_pfn, nid))
+ do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
+ return 0;
+}
+
+static int register_mem_block_early__normal(struct memory_block *mem_blk,
+ unsigned long start_pfn, unsigned long end_pfn, int nid)
+{
+ unsigned long pfn;
for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
int page_nid;

@@ -821,6 +826,22 @@ static int register_mem_block_under_node_early(struct memory_block *mem_blk,
/* mem section does not span the specified node */
return 0;
}
+/* register memory section under specified node if it spans that node */
+static int register_mem_block_under_node_early(struct memory_block *mem_blk,
+ void *arg)
+{
+ unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
+ unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
+ unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
+ int nid = *(int *)arg;
+
+#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
+ if (system_state < SYSTEM_RUNNING)
+ return register_mem_block_early_if_dfer_page_init(mem_blk, start_pfn, end_pfn, nid);
+#endif
+ return register_mem_block_early__normal(mem_blk, start_pfn, end_pfn, nid);
+
+}

/*
* During hotplug we know that all pages in the memory block belong to the same
--
2.48.1