diff --git a/src/percpu.rs b/src/percpu.rs
index f4ad5e6..1844d62 100644
--- a/src/percpu.rs
+++ b/src/percpu.rs
@@ -1,4 +1,5 @@
 use alloc::{
+    collections::VecDeque,
     sync::{Arc, Weak},
     vec::Vec,
 };
@@ -12,7 +13,10 @@ use syscall::PtraceFlags;
 
 use crate::{
     arch::device::ArchPercpuMisc,
-    context::{empty_cr3, memory::AddrSpaceWrapper, switch::ContextSwitchPercpu},
+    context::{
+        empty_cr3, memory::AddrSpaceWrapper, switch::ContextSwitchPercpu, WeakContextRef,
+        RUN_QUEUE_COUNT,
+    },
     cpu_set::{LogicalCpuId, MAX_CPU_COUNT},
     cpu_stats::{CpuStats, CpuStatsData},
     ptrace::Session,
@@ -20,6 +24,42 @@ use crate::{
     syscall::debug::SyscallDebugInfo,
 };
 
+#[allow(dead_code)]
+pub struct PerCpuSched {
+    pub run_queues: [VecDeque<WeakContextRef>; RUN_QUEUE_COUNT],
+    pub run_queues_lock: AtomicBool,
+    pub balance: Cell<[usize; RUN_QUEUE_COUNT]>,
+    pub last_queue: Cell<usize>,
+}
+
+impl PerCpuSched {
+    pub const fn new() -> Self {
+        const EMPTY: VecDeque<WeakContextRef> = VecDeque::new();
+        Self {
+            run_queues: [EMPTY; RUN_QUEUE_COUNT],
+            run_queues_lock: AtomicBool::new(false),
+            balance: Cell::new([0; RUN_QUEUE_COUNT]),
+            last_queue: Cell::new(0),
+        }
+    }
+
+    pub fn take_lock(&self) {
+        while self
+            .run_queues_lock
+            .compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed)
+            .is_err()
+        {
+            while self.run_queues_lock.load(Ordering::Relaxed) {
+                core::hint::spin_loop();
+            }
+        }
+    }
+
+    pub fn release_lock(&self) {
+        self.run_queues_lock.store(false, Ordering::Release);
+    }
+}
+
 /// The percpu block, that stored all percpu variables.
 pub struct PercpuBlock {
     /// A unique immutable number that identifies the current CPU - used for scheduling
@@ -31,7 +71,12 @@ pub struct PercpuBlock {
     pub current_addrsp: RefCell<Option<Arc<AddrSpaceWrapper>>>,
     pub new_addrsp_tmp: Cell<Option<Arc<AddrSpaceWrapper>>>,
     pub wants_tlb_shootdown: AtomicBool,
-    pub balance: Cell<[usize; 40]>,
+
+    pub sched: PerCpuSched,
+
+    // Legacy DWRR state used by context/switch.rs until the per-CPU scheduler migration is
+    // finished.
+    pub balance: Cell<[usize; RUN_QUEUE_COUNT]>,
     pub last_queue: Cell<usize>,
 
     // TODO: Put mailbox queues here, e.g. for TLB shootdown? Just be sure to 128-byte align it
@@ -187,7 +232,8 @@ impl PercpuBlock {
             current_addrsp: RefCell::new(None),
             new_addrsp_tmp: Cell::new(None),
             wants_tlb_shootdown: AtomicBool::new(false),
-            balance: Cell::new([0; 40]),
+            sched: PerCpuSched::new(),
+            balance: Cell::new([0; RUN_QUEUE_COUNT]),
             last_queue: Cell::new(39),
             ptrace_flags: Cell::new(PtraceFlags::empty()),
             ptrace_session: RefCell::new(None),