--- a/src/proc.c	Thu Jun 20 16:42:10 2019 +0900
+++ b/src/proc.c	Thu Jun 20 19:08:58 2019 +0900
@@ -315,18 +315,23 @@
 int get_highest_priority_proc(void)
 {
   int highest_priority;
-   highest_priority=ptable.proc->priority;
-   struct proc *p;
-  for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
+  int pid = 0;
+  int hpid = -1;
+  int rpid = 0;
+
+  highest_priority=100;
+  struct proc *p;
+  for(p = ptable.proc; p < &ptable.proc[NPROC]; p++, pid++){
     if(p->state != RUNNABLE) {
       continue;
-    }   
-    if (highest_priority > p->priority)
-     {
+    }
+    rpid = pid;
+    if (highest_priority > p->priority) {
        highest_priority=p->priority;
-     }
+       hpid = pid;
+    }
   }
-  return highest_priority;
+  return hpid > 0?hpid:rpid;
 }
 
 //PAGEBREAK: 42
@@ -347,14 +352,15 @@
 
         // Loop over process table looking for process to run.
         acquire(&ptable.lock);
-    #if (0)      
+    #if (1)      
         int highest_priority = get_highest_priority_proc();
               
             // Switch to chosen process.  It is the process's job
             // to release ptable.lock and then reacquire it
             // before jumping back to us.
-	 
-          p=&ptable.proc[highest_priority];
+	       if (highest_priority >= 0) { 
+            p = &ptable.proc[highest_priority];
+	          proc = p;
             switchuvm(p);
          
             p->state = RUNNING;
@@ -364,9 +370,10 @@
             // Process is done running for now.
             // It should have changed its p->state before coming back.
             proc = 0;
+         }
        #else
            
-	    for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
+	    for(p = ptable.proc; p < &ptable.proc[NPROC]; p++) {
 	      if(p->state != RUNNABLE) {
                 continue;
 	      }

--- a/src/tools/mkfs.c	Thu Jun 20 16:42:10 2019 +0900
+++ b/src/tools/mkfs.c	Thu Jun 20 19:08:58 2019 +0900
@@ -11,7 +11,7 @@
 #include "stat.h"
 #include "param.h"
 
-#define static_assert(a, b) do { switch (0) case 0: case (a): ; } while (0)
+// #define static_assert(a, b) do { switch (0) case 0: case (a): ; } while (0)
 
 int nblocks = 985;
 int nlog = LOGSIZE;

--- a/src/usr/Makefile	Thu Jun 20 16:42:10 2019 +0900
+++ b/src/usr/Makefile	Thu Jun 20 19:08:58 2019 +0900
@@ -24,7 +24,8 @@
 	_zombie\
 	_hello\
 	_forktest\
-	_check\
+	
+# _check\
 
 all: $(FS_IMAGE)
 

--- a/src/usr/usertests.c	Thu Jun 20 16:42:10 2019 +0900
+++ b/src/usr/usertests.c	Thu Jun 20 19:08:58 2019 +0900
@@ -1606,13 +1606,16 @@
   int pid;
 
   pid = fork();
-  if(pid != 0)
-  {
-    if (getpriority()==10)
+  if (pid != 0) {
+    if (getpriority()==10) {
       printf(1,"Okay\n"); 
-   setpriority(5);  
-   if (getpriority()==5) 
-     printf(1,"Okay\n");      
+    } else {
+      printf(1,"Bad\n"); 
+    }
+    setpriority(5);  
+    if (getpriority()==5) {
+      printf(1,"Okay\n");
+    }    
   }
   return;
 }
@@ -1628,6 +1631,7 @@
     }
     close(open("usertests.ran", O_CREATE));
     
+    testpriority();
     bigargtest();
     bigwrite();
     bigargtest();
@@ -1660,7 +1664,6 @@
     iref();
     forktest();
     bigdir(); // slow
-    testpriority();
     exectest();
     
     exit();