This patch adds a new knob `detect_node_addresses`, which determines
whether the physical address range is set manually using the existing
knobs or automatically by the mtier module. When `detect_node_addresses`
set to 'Y', mtier automatically converts node0 and node1 to their
physical addresses. If set to 'N', it uses the existing
'node#_start_addr' and 'node#_end_addr' to define regions as before.

Suggested-by: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Yunjeong Mun <yunjeong.mun@sk.com>
---
v3 -> v4: Cleand up the 'nid_to_phys' function code
RFC v2 -> v3: removed an unusable comment
RFC v1 -> RFC v2
- dropped the second patch as the newly added knob is no longer needed.
- added a new knob 'detect_node_addresses'
- renamed the function for clarity: numa_info_init -> nid_to_phys
- cleaned up code

v3:
https://lore.kernel.org/all/20250707023135.453-1-yunjeong.mun@sk.com
RFC v2:
https://lore.kernel.org/20250703074423.1771-1-yunjeong.mun@sk.com
RFC v1:
https://lore.kernel.org/20250701085417.1734-1-yunjeong.mun@sk.com
---
 samples/damon/mtier.c | 37 ++++++++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/samples/damon/mtier.c b/samples/damon/mtier.c
index f3220d6e6739..2513f0707986 100644
--- a/samples/damon/mtier.c
+++ b/samples/damon/mtier.c
@@ -42,8 +42,29 @@ static bool enable __read_mostly;
 module_param_cb(enable, &enable_param_ops, &enable, 0600);
 MODULE_PARM_DESC(enable, "Enable of disable DAMON_SAMPLE_MTIER");
 
+static bool detect_node_addresses __read_mostly;
+module_param(detect_node_addresses, bool, 0600);
+
 static struct damon_ctx *ctxs[2];
 
+struct region_range {
+	phys_addr_t start;
+	phys_addr_t end;
+};
+
+static int nid_to_phys(int target_node, struct region_range *range)
+{
+	if (!node_online(target_node)) {
+		pr_err("NUMA node %d is not online\n", target_node);
+		return -EINVAL;
+	}
+
+	range->start = PFN_PHYS(node_start_pfn(target_node));
+	range->end  = PFN_PHYS(node_end_pfn(target_node));
+
+	return 0;
+}
+
 static struct damon_ctx *damon_sample_mtier_build_ctx(bool promote)
 {
 	struct damon_ctx *ctx;
@@ -53,6 +74,8 @@ static struct damon_ctx *damon_sample_mtier_build_ctx(bool promote)
 	struct damos *scheme;
 	struct damos_quota_goal *quota_goal;
 	struct damos_filter *filter;
+	struct region_range addr;
+	int ret;
 
 	ctx = damon_new_ctx();
 	if (!ctx)
@@ -82,9 +105,17 @@ static struct damon_ctx *damon_sample_mtier_build_ctx(bool promote)
 	if (!target)
 		goto free_out;
 	damon_add_target(ctx, target);
-	region = damon_new_region(
-			promote ? node1_start_addr : node0_start_addr,
-			promote ? node1_end_addr : node0_end_addr);
+
+	if (detect_node_addresses) {
+		ret = promote ? nid_to_phys(1, &addr) : nid_to_phys(0, &addr);
+		if (ret)
+			goto free_out;
+	} else {
+		addr.start = promote ? node1_start_addr : node0_start_addr;
+		addr.end = promote ? node1_end_addr : node0_end_addr;
+	}
+
+	region = damon_new_region(addr.start, addr.end);
 	if (!region)
 		goto free_out;
 	damon_add_region(region, target);

base-commit: db16fe88cdf83a1e7fdf75de282025b6ad61d08f
-- 
2.34.1

Hello Yunjeong,

On Tue,  8 Jul 2025 08:59:18 +0900 Yunjeong Mun <yunjeong.mun@sk.com> wrote:

> This patch adds a new knob `detect_node_addresses`, which determines
> whether the physical address range is set manually using the existing
> knobs or automatically by the mtier module. When `detect_node_addresses`
> set to 'Y', mtier automatically converts node0 and node1 to their
> physical addresses. If set to 'N', it uses the existing
> 'node#_start_addr' and 'node#_end_addr' to define regions as before.

Thank you for sending this patch :)
> 
> Suggested-by: Honggyu Kim <honggyu.kim@sk.com>
> Signed-off-by: Yunjeong Mun <yunjeong.mun@sk.com>

Reviewed-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

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