diff --git a/labcodes/lab6/kern/schedule/sched.h b/labcodes/lab6/kern/schedule/sched.h
index ca33799..766ac03 100644
--- a/labcodes/lab6/kern/schedule/sched.h
+++ b/labcodes/lab6/kern/schedule/sched.h
@@ -5,7 +5,7 @@
 #include <list.h>
 #include <skew_heap.h>
 
-#define MAX_TIME_SLICE 20
+#define MAX_TIME_SLICE 5
 
 struct proc_struct;
 
diff --git a/labcodes/lab6/user/priority.c b/labcodes/lab6/user/priority.c
index bcbc29d..6a1cae4 100644
--- a/labcodes/lab6/user/priority.c
+++ b/labcodes/lab6/user/priority.c
@@ -5,7 +5,7 @@
 
 #define TOTAL 5
 /* to get enough accuracy, MAX_TIME (the running time of each process) should >1000 mseconds. */
-#define MAX_TIME  2000
+#define MAX_TIME  1000
 unsigned int acc[TOTAL];
 int status[TOTAL];
 int pids[TOTAL];
diff --git a/labcodes/lab7/kern/schedule/sched.c b/labcodes/lab7/kern/schedule/sched.c
index 8c3ff99..53c2e3c 100644
--- a/labcodes/lab7/kern/schedule/sched.c
+++ b/labcodes/lab7/kern/schedule/sched.c
@@ -49,7 +49,7 @@ sched_init(void) {
     sched_class = &default_sched_class;
 
     rq = &__rq;
-    rq->max_time_slice = 20;
+    rq->max_time_slice = 5;
     sched_class->init(rq);
 
     cprintf("sched class: %s\n", sched_class->name);
diff --git a/labcodes/lab7/kern/schedule/sched.h b/labcodes/lab7/kern/schedule/sched.h
index ca33799..766ac03 100644
--- a/labcodes/lab7/kern/schedule/sched.h
+++ b/labcodes/lab7/kern/schedule/sched.h
@@ -5,7 +5,7 @@
 #include <list.h>
 #include <skew_heap.h>
 
-#define MAX_TIME_SLICE 20
+#define MAX_TIME_SLICE 5
 
 struct proc_struct;
 
diff --git a/labcodes/lab7/user/priority.c b/labcodes/lab7/user/priority.c
index d71147e..d097270 100644
--- a/labcodes/lab7/user/priority.c
+++ b/labcodes/lab7/user/priority.c
@@ -5,7 +5,7 @@
 
 #define TOTAL 5
 /* to get enough accuracy, MAX_TIME (the running time of each process) should >1000 mseconds. */
-#define MAX_TIME  2000
+#define MAX_TIME  1000
 #define SLEEP_TIME 400
 unsigned int acc[TOTAL];
 int status[TOTAL];
@@ -39,7 +39,7 @@ main(void) {
                     spin_delay();
                     ++ acc[i];
                     if(acc[i]%4000==0) {
-                        if((time=gettime_msec())>MAX_TIME) {
+                        if((time=gettime_msec())>MAX_TIME+SLEEP_TIME) {
                             cprintf("child pid %d, acc %d, time %d\n",getpid(),acc[i],time);
                             exit(acc[i]);
                         }
diff --git a/labcodes/lab8/kern/schedule/sched.h b/labcodes/lab8/kern/schedule/sched.h
index ca33799..766ac03 100644
--- a/labcodes/lab8/kern/schedule/sched.h
+++ b/labcodes/lab8/kern/schedule/sched.h
@@ -5,7 +5,7 @@
 #include <list.h>
 #include <skew_heap.h>
 
-#define MAX_TIME_SLICE 20
+#define MAX_TIME_SLICE 5
 
 struct proc_struct;
 
diff --git a/labcodes/lab8/user/priority.c b/labcodes/lab8/user/priority.c
index d71147e..5624ec6 100644
--- a/labcodes/lab8/user/priority.c
+++ b/labcodes/lab8/user/priority.c
@@ -5,7 +5,7 @@
 
 #define TOTAL 5
 /* to get enough accuracy, MAX_TIME (the running time of each process) should >1000 mseconds. */
-#define MAX_TIME  2000
+#define MAX_TIME  1000
 #define SLEEP_TIME 400
 unsigned int acc[TOTAL];
 int status[TOTAL];
@@ -39,7 +39,7 @@ main(void) {
                     spin_delay();
                     ++ acc[i];
                     if(acc[i]%4000==0) {
-                        if((time=gettime_msec())>MAX_TIME) {
+                        if((time=gettime_msec())>SLEEP_TIME+MAX_TIME) {
                             cprintf("child pid %d, acc %d, time %d\n",getpid(),acc[i],time);
                             exit(acc[i]);
                         }
diff --git a/labcodes_answer/lab6_result/kern/schedule/sched.h b/labcodes_answer/lab6_result/kern/schedule/sched.h
index ca33799..766ac03 100644
--- a/labcodes_answer/lab6_result/kern/schedule/sched.h
+++ b/labcodes_answer/lab6_result/kern/schedule/sched.h
@@ -5,7 +5,7 @@
 #include <list.h>
 #include <skew_heap.h>
 
-#define MAX_TIME_SLICE 20
+#define MAX_TIME_SLICE 5
 
 struct proc_struct;
 
diff --git a/labcodes_answer/lab6_result/user/priority.c b/labcodes_answer/lab6_result/user/priority.c
index bcbc29d..6a1cae4 100644
--- a/labcodes_answer/lab6_result/user/priority.c
+++ b/labcodes_answer/lab6_result/user/priority.c
@@ -5,7 +5,7 @@
 
 #define TOTAL 5
 /* to get enough accuracy, MAX_TIME (the running time of each process) should >1000 mseconds. */
-#define MAX_TIME  2000
+#define MAX_TIME  1000
 unsigned int acc[TOTAL];
 int status[TOTAL];
 int pids[TOTAL];
diff --git a/labcodes_answer/lab7_result/kern/schedule/sched.c b/labcodes_answer/lab7_result/kern/schedule/sched.c
index e272635..c0dab33 100644
--- a/labcodes_answer/lab7_result/kern/schedule/sched.c
+++ b/labcodes_answer/lab7_result/kern/schedule/sched.c
@@ -48,7 +48,7 @@ sched_init(void) {
     sched_class = &default_sched_class;
 
     rq = &__rq;
-    rq->max_time_slice = 20;
+    rq->max_time_slice = 5;
     sched_class->init(rq);
 
     cprintf("sched class: %s\n", sched_class->name);
diff --git a/labcodes_answer/lab7_result/user/priority.c b/labcodes_answer/lab7_result/user/priority.c
index d71147e..d097270 100644
--- a/labcodes_answer/lab7_result/user/priority.c
+++ b/labcodes_answer/lab7_result/user/priority.c
@@ -5,7 +5,7 @@
 
 #define TOTAL 5
 /* to get enough accuracy, MAX_TIME (the running time of each process) should >1000 mseconds. */
-#define MAX_TIME  2000
+#define MAX_TIME  1000
 #define SLEEP_TIME 400
 unsigned int acc[TOTAL];
 int status[TOTAL];
@@ -39,7 +39,7 @@ main(void) {
                     spin_delay();
                     ++ acc[i];
                     if(acc[i]%4000==0) {
-                        if((time=gettime_msec())>MAX_TIME) {
+                        if((time=gettime_msec())>MAX_TIME+SLEEP_TIME) {
                             cprintf("child pid %d, acc %d, time %d\n",getpid(),acc[i],time);
                             exit(acc[i]);
                         }
diff --git a/labcodes_answer/lab8_result/kern/schedule/sched.c b/labcodes_answer/lab8_result/kern/schedule/sched.c
index e272635..c0dab33 100644
--- a/labcodes_answer/lab8_result/kern/schedule/sched.c
+++ b/labcodes_answer/lab8_result/kern/schedule/sched.c
@@ -48,7 +48,7 @@ sched_init(void) {
     sched_class = &default_sched_class;
 
     rq = &__rq;
-    rq->max_time_slice = 20;
+    rq->max_time_slice = 5;
     sched_class->init(rq);
 
     cprintf("sched class: %s\n", sched_class->name);
diff --git a/labcodes_answer/lab8_result/user/priority.c b/labcodes_answer/lab8_result/user/priority.c
index d71147e..5624ec6 100644
--- a/labcodes_answer/lab8_result/user/priority.c
+++ b/labcodes_answer/lab8_result/user/priority.c
@@ -5,7 +5,7 @@
 
 #define TOTAL 5
 /* to get enough accuracy, MAX_TIME (the running time of each process) should >1000 mseconds. */
-#define MAX_TIME  2000
+#define MAX_TIME  1000
 #define SLEEP_TIME 400
 unsigned int acc[TOTAL];
 int status[TOTAL];
@@ -39,7 +39,7 @@ main(void) {
                     spin_delay();
                     ++ acc[i];
                     if(acc[i]%4000==0) {
-                        if((time=gettime_msec())>MAX_TIME) {
+                        if((time=gettime_msec())>SLEEP_TIME+MAX_TIME) {
                             cprintf("child pid %d, acc %d, time %d\n",getpid(),acc[i],time);
                             exit(acc[i]);
                         }