after heavy problem solved

proc.c

@@ -322,6 +322,7 @@ wait(void)
 void
 scheduler(void)
 {
+  extern int cpuMode;
   struct proc *p;
   struct cpu *c = mycpu();
   struct proc *p1;

proc.h

@@ -12,7 +12,7 @@ struct cpu {
 
 extern struct cpu cpus[NCPU];
 extern int ncpu;
-extern int cpuMode;// this field show how schedule system use
+int cpuMode;// this field show how schedule system use
 
 
 //PAGEBREAK: 17

sysproc.c

@@ -140,7 +140,7 @@ sys_getCount(int find){
 
 //3.2
 int
-changePriority(int newPriority){
+sys_changePriority(int newPriority){
   argint(0,&newPriority);
   if(newPriority > 5 || newPriority < 0){
     return -1;

trap.c

@@ -11,6 +11,7 @@
 // Interrupt descriptor table (shared by all CPUs).
 struct gatedesc idt[256];
 extern uint vectors[];  // in vectors.S: array of 256 entry pointers
+extern int cpuMode; // kashani
 struct spinlock tickslock;
 uint ticks;
 int currentQuantom ; //show us how many quantom passed in this procces