diff --git a/src/numa.rs b/src/numa.rs
new file mode 100644
index 0000000..40c5a06
--- /dev/null
+++ b/src/numa.rs
@@ -0,0 +1,62 @@
+/// NUMA topology hints for the kernel scheduler.
+/// NUMA discovery (SRAT/SLIT parsing) is performed by a userspace daemon
+/// (numad) via /scheme/acpi/, then pushed to the kernel via scheme:numa.
+/// The kernel stores a lightweight copy for O(1) scheduling lookups.
+use crate::cpu_set::{LogicalCpuId, LogicalCpuSet};
+use core::sync::atomic::{AtomicBool, Ordering};
+
+const MAX_NUMA_NODES: usize = 8;
+
+#[derive(Clone, Debug)]
+pub struct NumaHint {
+    pub node_id: u8,
+    pub cpus: LogicalCpuSet,
+}
+
+pub struct NumaTopology {
+    pub nodes: [Option<NumaHint>; MAX_NUMA_NODES],
+    pub initialized: AtomicBool,
+}
+
+impl NumaTopology {
+    pub const fn new() -> Self {
+        const NONE: Option<NumaHint> = None;
+        Self {
+            nodes: [NONE; MAX_NUMA_NODES],
+            initialized: AtomicBool::new(false),
+        }
+    }
+
+    pub fn node_for_cpu(&self, cpu: LogicalCpuId) -> Option<u8> {
+        for node in self.nodes.iter().flatten() {
+            if node.cpus.contains(cpu) {
+                return Some(node.node_id);
+            }
+        }
+        None
+    }
+
+    pub fn same_node(&self, cpu1: LogicalCpuId, cpu2: LogicalCpuId) -> bool {
+        self.node_for_cpu(cpu1) == self.node_for_cpu(cpu2)
+    }
+}
+
+static mut NUMA_TOPOLOGY: NumaTopology = NumaTopology::new();
+
+pub fn topology() -> &'static NumaTopology {
+    unsafe { &NUMA_TOPOLOGY }
+}
+
+pub fn init_default() {
+    let topo = topology();
+    if topo.initialized.swap(true, Ordering::AcqRel) {
+        return;
+    }
+    unsafe {
+        let topo_mut = &mut *core::ptr::addr_of_mut!(NUMA_TOPOLOGY);
+        topo_mut.nodes[0] = Some(NumaHint {
+            node_id: 0,
+            cpus: LogicalCpuSet::all(),
+        });
+    }
+}