[PATCH 0/9] treewide, numa_memblks: remove redundant work during NUMA init

[PATCH 0/9] treewide, numa_memblks: remove redundant work during NUMA init

[Sang-Heon Jeon]

Every existing numa_add_memblk() caller passes a valid node id and
separately marks that node in numa_nodes_parsed with node_set(). In
addition, numa_nodemask_from_meminfo() recomputes the same "nodes that own
memory" set from numa_meminfo, which numa_nodes_parsed already contains.

This redundancy implicitly depends on the callers' node_set(). So, before
removing the redundancy, make numa_add_memblk() set the node in
numa_nodes_parsed explicitly. Then remove the per-caller node_set() and
numa_nodemask_from_meminfo().

Also, since the generic numa_register_meminfo() already sets
node_possible_map to numa_nodes_parsed, remove the duplicate assignment in
arch_numa's numa_register_nodes().

Patch 1 adds the node_set() to numa_add_memblk() itself, so every memblk's
node is set in numa_nodes_parsed on add.

Patches 2-6 depend on patch 1 and remove the redundant per-caller node_set()
from all callers.

Patch 7 removes both numa_nodemask_from_meminfo() call sites and the unused
function itself.

Patch 8 removes the duplicate node_possible_map assignment in arch_numa.

Patch 9 is a minor cleanup, using the existing numa_add_reserved_memblk()
wrapper in numa_cleanup_meminfo().

No functional change.

Sang-Heon Jeon (9):
  mm: numa_memblks: set numa_nodes_parsed in numa_add_memblk()
  ACPI: NUMA: remove redundant numa_nodes_parsed node_set()
  of/numa: remove redundant numa_nodes_parsed node_set()
  x86/numa: remove redundant numa_nodes_parsed node_set()
  arch_numa: remove redundant numa_nodes_parsed node_set()
  LoongArch: remove redundant numa_nodes_parsed node_set()
  mm: numa_memblks: remove redundant numa_nodemask_from_meminfo()
  arch_numa: remove redundant node_possible_map assignment
  mm: numa_memblks: use numa_add_reserved_memblk() in
    numa_cleanup_meminfo()

 arch/loongarch/kernel/numa.c |  1 -
 arch/x86/mm/amdtopology.c    |  1 -
 arch/x86/mm/numa.c           |  1 -
 drivers/acpi/numa/srat.c     |  2 --
 drivers/base/arch_numa.c     |  4 ----
 drivers/of/of_numa.c         |  5 +----
 mm/numa_memblks.c            | 41 +++++++++++++++---------------------
 7 files changed, 18 insertions(+), 37 deletions(-)

-- 
2.43.0

[PATCH 1/9] mm: numa_memblks: set numa_nodes_parsed in numa_add_memblk()

[Sang-Heon Jeon]

Every existing numa_add_memblk() caller separately marks the new node in
numa_nodes_parsed with node_set(). Set the node in numa_add_memblk() itself
on a successful add, so this no longer depends on each caller.

numa_add_memblk_to() now returns -EINVAL for an out-of-range node id, so a
zero return implies @nid was valid. No existing caller passes an 
invalid one, so existing callers are unaffected.

The per-caller node_set() calls are removed in later patches.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
 mm/numa_memblks.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
index 3c3c4eac3514..2d92ca38c02a 100644
--- a/mm/numa_memblks.c
+++ b/mm/numa_memblks.c
@@ -135,14 +135,17 @@ EXPORT_SYMBOL(__node_distance);
 static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
 				     struct numa_meminfo *mi)
 {
-	/* ignore zero length blks */
-	if (start == end)
-		return 0;
-
 	/* whine about and ignore invalid blks */
-	if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
+	if (nid < 0 || nid >= MAX_NUMNODES) {
 		pr_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
 			nid, start, end - 1);
+		return -EINVAL;
+	}
+
+	/* ignore zero length or invalid blks */
+	if (start >= end) {
+		pr_warn("Warning: invalid memblk node size %d [mem %#010Lx-%#010Lx]\n",
+			nid, start, end - 1);
 		return 0;
 	}
 
@@ -193,13 +196,20 @@ static void __init numa_move_tail_memblk(struct numa_meminfo *dst, int idx,
  * @end: End address of the new memblk
  *
  * Add a new memblk to the default numa_meminfo.
+ * On success @nid is also set in numa_nodes_parsed.
  *
  * RETURNS:
  * 0 on success, -errno on failure.
  */
 int __init numa_add_memblk(int nid, u64 start, u64 end)
 {
-	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
+	int ret;
+
+	ret = numa_add_memblk_to(nid, start, end, &numa_meminfo);
+	if (!ret)
+		node_set(nid, numa_nodes_parsed);
+
+	return ret;
 }
 
 /**
-- 
2.43.0

[PATCH 7/9] mm: numa_memblks: remove redundant numa_nodemask_from_meminfo()

[Sang-Heon Jeon]

numa_add_memblk() now sets each added node in numa_nodes_parsed, so
numa_nodes_parsed already contains every node that owns memory. The nodes
numa_nodemask_from_meminfo() adds from numa_meminfo are already set, so the
calls in numa_alloc_distance() and numa_register_meminfo() are redundant.

So remove both call sites and the unused function itself.

No functional change.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
 mm/numa_memblks.c | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
index 2d92ca38c02a..edc231538954 100644
--- a/mm/numa_memblks.c
+++ b/mm/numa_memblks.c
@@ -17,20 +17,6 @@ nodemask_t numa_nodes_parsed __initdata;
 static struct numa_meminfo numa_meminfo __initdata_or_meminfo;
 static struct numa_meminfo numa_reserved_meminfo __initdata_or_meminfo;
 
-/*
- * Set nodes, which have memory in @mi, in *@nodemask.
- */
-static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
-					      const struct numa_meminfo *mi)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
-		if (mi->blk[i].start != mi->blk[i].end &&
-		    mi->blk[i].nid != NUMA_NO_NODE)
-			node_set(mi->blk[i].nid, *nodemask);
-}
-
 /**
  * numa_reset_distance - Reset NUMA distance table
  *
@@ -56,7 +42,6 @@ static int __init numa_alloc_distance(void)
 
 	/* size the new table and allocate it */
 	nodes_parsed = numa_nodes_parsed;
-	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
 
 	for_each_node_mask(i, nodes_parsed)
 		cnt = i;
@@ -411,7 +396,6 @@ static int __init numa_register_meminfo(struct numa_meminfo *mi)
 
 	/* Account for nodes with cpus and no memory */
 	node_possible_map = numa_nodes_parsed;
-	numa_nodemask_from_meminfo(&node_possible_map, mi);
 	if (WARN_ON(nodes_empty(node_possible_map)))
 		return -EINVAL;
 
-- 
2.43.0

[PATCH 9/9] mm: numa_memblks: use numa_add_reserved_memblk() in numa_cleanup_meminfo()

[Sang-Heon Jeon]

numa_cleanup_meminfo() calls the internal numa_add_memblk_to() to add a
block to numa_reserved_meminfo, even though numa_add_reserved_memblk()
wraps exactly that.

Use the wrapper instead, so numa_add_memblk_to() is only called through
its two wrappers.

No functional change.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
 mm/numa_memblks.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
index edc231538954..86b84a89fd9e 100644
--- a/mm/numa_memblks.c
+++ b/mm/numa_memblks.c
@@ -251,8 +251,7 @@ int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
 
 		/* preserve info for non-RAM areas above 'max_pfn': */
 		if (bi->end > high) {
-			numa_add_memblk_to(bi->nid, high, bi->end,
-					   &numa_reserved_meminfo);
+			numa_add_reserved_memblk(bi->nid, high, bi->end);
 			bi->end = high;
 		}
 
-- 
2.43.0

Re: [PATCH 1/9] mm: numa_memblks: set numa_nodes_parsed in numa_add_memblk()

[Mike Rapoport]

On Thu, Jul 02, 2026 at 10:43:40PM +0900, Sang-Heon Jeon wrote:
> Hi, Mike
> 
> On Thu, Jul 2, 2026 at 7:38 PM Mike Rapoport <rppt@kernel.org> wrote:
> >
> > > Every existing numa_add_memblk() caller separately marks the new node in
> > > numa_nodes_parsed with node_set(). Set the node in numa_add_memblk() itself
> > > on a successful add, so this no longer depends on each caller.
> > >
> > > numa_add_memblk_to() now returns -EINVAL for an out-of-range node id, so a
> > > zero return implies @nid was valid. No existing caller passes an
> > > invalid one, so existing callers are unaffected.
> > >
> > > The per-caller node_set() calls are removed in later patches.
> > >
> > > Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
> > >
> > > diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
> > > index 3c3c4eac3514..2d92ca38c02a 100644
> > > --- a/mm/numa_memblks.c
> > > +++ b/mm/numa_memblks.c
> > > @@ -135,14 +135,17 @@ EXPORT_SYMBOL(__node_distance);
> > >  static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
> > >                                    struct numa_meminfo *mi)
> > >  {
> > > -     /* ignore zero length blks */
> > > -     if (start == end)
> > > -             return 0;
> > > -
> > >       /* whine about and ignore invalid blks */
> > > -     if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
> > > +     if (nid < 0 || nid >= MAX_NUMNODES) {
> > >               pr_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
> > >                       nid, start, end - 1);
> > > +             return -EINVAL;
> > > +     }
> > > +
> > > +     /* ignore zero length or invalid blks */
> > > +     if (start >= end) {
> > > +             pr_warn("Warning: invalid memblk node size %d [mem %#010Lx-%#010Lx]\n",
> > > +                     nid, start, end - 1);
> >
> > Nit: any reason to put this check here instead of replacing
> >
> >         if (start == end)
> >
> > ?
> 
> Reordering is needed to ensure the following node_set() is not called
> with an invalid nid.
> While doing that, I thought the start == end condition is the same
> kind of invalid blk, so I moved it into the warning block.
> But no strong opinion here though. Should I go back to not printing
> the warning for start == end in v2?

Yeah, please skip the warning in v2.
 
> > --
> > Sincerely yours,
> > Mike.
> >
> 
> Best Regards,
> Sang-Heon Jeon

-- 
Sincerely yours,
Mike.