+ mm-page_owner-add-numa-node-filter-with-nodelist-support.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/page_owner: add NUMA node filter with nodelist support
has been added to the -mm mm-new branch.  Its filename is
     mm-page_owner-add-numa-node-filter-with-nodelist-support.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_owner-add-numa-node-filter-with-nodelist-support.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Zhen Ni <zhen.ni@easystack.cn>
Subject: mm/page_owner: add NUMA node filter with nodelist support
Date: Sun, 19 Apr 2026 23:55:40 +0800

Add NUMA node filtering functionality to page_owner to allow filtering
pages by specific NUMA node(s) using nodelist format.

The filter allows users to focus on pages from specific NUMA nodes, which
is useful for NUMA-aware memory allocation analysis and debugging.

Supported input formats:
- Single node: echo "2" > nid
- Multiple nodes: echo "0,2,3" > nid
- Node range: echo "0-3" > nid
- Mixed format: echo "0,2-4,7" > nid
- Disable filter: echo "-1" > nid

Link: https://lore.kernel.org/linux-mm/20260417154638.22370-4-zhen.ni@easystack.cn/
Link: https://lore.kernel.org/20260419155540.376847-4-zhen.ni@easystack.cn
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Suggested-by: Zi Yan <ziy@nvidia.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_owner.c |   76 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

--- a/mm/page_owner.c~mm-page_owner-add-numa-node-filter-with-nodelist-support
+++ a/mm/page_owner.c
@@ -707,6 +707,7 @@ read_page_owner(struct file *file, char
 		 * user through copy_to_user() or GFP_KERNEL allocations.
 		 */
 		struct page_owner page_owner_tmp;
+		nodemask_t mask;
 
 		/*
 		 * If the new page is in a new MAX_ORDER_NR_PAGES area,
@@ -730,6 +731,15 @@ read_page_owner(struct file *file, char
 		if (unlikely(!page_ext))
 			continue;
 
+		/* NUMA node filter using bitmask */
+		mask = READ_ONCE(owner_filter.nid_mask);
+		if (!nodes_empty(mask)) {
+			int nid = page_to_nid(page);
+
+			if (!node_isset(nid, mask))
+				goto ext_put_continue;
+		}
+
 		/*
 		 * Some pages could be missed by concurrent allocation or free,
 		 * because we don't hold the zone lock.
@@ -1009,6 +1019,70 @@ DEFINE_SIMPLE_ATTRIBUTE(page_owner_print
 			&page_owner_print_mode_get,
 			&page_owner_print_mode_set, "%lld");
 
+static ssize_t nid_filter_write(struct file *file,
+				 const char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	char *kbuf;
+	nodemask_t mask;
+	int ret;
+
+	/* Limit input size to handle worst-case nodelist (all nodes) */
+	if (count > (100 + 6 * MAX_NUMNODES))
+		return -EINVAL;
+
+	kbuf = kmalloc(count + 1, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	if (copy_from_user(kbuf, buf, count)) {
+		ret = -EFAULT;
+		goto out_free;
+	}
+	kbuf[count] = '\0';
+
+	/* Support: "-1" to clear, or nodelist format like "0", "0,2", "0-3" */
+	if (strcmp(kbuf, "-1\n") == 0 || strcmp(kbuf, "-1") == 0)
+		nodes_clear(mask);
+	else if (nodelist_parse(kbuf, mask)) {
+		ret = -EINVAL;
+		goto out_free;
+	}
+
+	WRITE_ONCE(owner_filter.nid_mask, mask);
+	ret = count;
+
+out_free:
+	kfree(kbuf);
+	return ret;
+}
+
+static int nid_filter_show(struct seq_file *m, void *v)
+{
+	nodemask_t mask = READ_ONCE(owner_filter.nid_mask);
+
+	if (nodes_empty(mask))
+		seq_puts(m, "-1\n");
+	else
+		seq_printf(m, "%*pbl\n", nodemask_pr_args(&mask));
+
+	return 0;
+}
+
+static int nid_filter_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, nid_filter_show, NULL);
+}
+
+static const struct file_operations nid_filter_fops = {
+	.owner		= THIS_MODULE,
+	.open		= nid_filter_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.write		= nid_filter_write,
+	.release	= single_release,
+};
+
 
 static int __init pageowner_init(void)
 {
@@ -1024,6 +1098,8 @@ static int __init pageowner_init(void)
 	filter_dir = debugfs_create_dir("page_owner_filter", NULL);
 	debugfs_create_file("print_mode", 0600, filter_dir, NULL,
 			    &page_owner_print_mode_fops);
+	debugfs_create_file("nid", 0600, filter_dir, NULL,
+			    &nid_filter_fops);
 
 	dir = debugfs_create_dir("page_owner_stacks", NULL);
 	debugfs_create_file("show_stacks", 0400, dir,
_

Patches currently in -mm which might be from zhen.ni@easystack.cn are

mm-page_owner-add-filter-infrastructure.patch
mm-page_owner-add-print_mode-filter.patch
mm-page_owner-add-numa-node-filter-with-nodelist-support.patch