diff --git a/src/context/mod.rs b/src/context/mod.rs
index 37c73f5a37..ab45a3a571 100644
--- a/src/context/mod.rs
+++ b/src/context/mod.rs
@@ -29,6 +29,14 @@ pub use self::{
 pub type ContextLock = RwLock<L4, Context>;
 pub type ArcContextLockWriteGuard = ArcRwLockWriteGuard<L4, Context>;
 
+/// Number of priority queues in the per-CPU run queue (DWRR priority
+/// count). Kept at 40 to match the historical global `RunContextData.set`
+/// length and the existing `SCHED_PRIO_TO_WEIGHT` table in
+/// `context/switch.rs`. Each `PerCpuSched.run_queues` entry is one
+/// DWRR priority level. Consumers: `crate::percpu::PerCpuSched`,
+/// `crate::context::switch`.
+pub const RUN_QUEUE_COUNT: usize = 40;
+
 #[cfg(target_arch = "aarch64")]
 #[path = "arch/aarch64.rs"]
 mod arch;