diff --git a/lib/proc.c b/lib/proc.c
index aa28a41..73aec31 100644
--- a/lib/proc.c
+++ b/lib/proc.c
@@ -2,18 +2,7 @@
 
 struct Cpu cpus[NCPU];
 
-// Must be called with interrupts disabled,
-// to prevent race with process being moved
-// to a different CPU.
-int cpuid() {
-    int id = r_tp();
-    return id;
-}
-
-// Return this CPU's cpu struct.
-// Interrupts must be disabled.
-struct Cpu *mycpu(void) {
-    int         id = cpuid();
-    struct Cpu *c = &cpus[id];
-    return c;
-}
+/**
+ * Return this CPU's cpu struct. Interrupts must be disabled.
+ */
+inline struct Cpu *mycpu(void) { return &cpus[r_tp()]; }
diff --git a/lib/proc.h b/lib/proc.h
index 67749a2..1208b2b 100644
--- a/lib/proc.h
+++ b/lib/proc.h
@@ -3,7 +3,6 @@
 #include <riscv.h>
 #include <types.h>
 
-int         cpuid(void);
 struct Cpu *mycpu(void);
 
 /** Saved registers for kernel context switches. */