5 files changed, 50 insertions, 19 deletions

diff --git a/Makefile b/Makefile
index c311787..ae187e0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-KERNEL_DIR = ../litmus
+KERNEL_DIR = ../q08
 
 INC=-Iinclude/ -I${KERNEL_DIR}/include/
 
@@ -43,7 +43,7 @@ rt_launch: liblitmus.a litmus.h rt_launch.o
 stdump: liblitmus.a litmus.h sched_trace.h stdump.o
         cc -o stdump  stdump.o ${LIBS}
 
-liblitmus.a:  ${LIB_OBJ} litmus.h 
+liblitmus.a:  ${LIB_OBJ} litmus.h
         ${AR} rcs liblitmus.a ${LIB_OBJ}
 
 check:
diff --git a/include/internal.h b/include/internal.h
index 25e1573..761c434 100644
--- a/include/internal.h
+++ b/include/internal.h
@@ -5,7 +5,7 @@
 
 /* prepare a real-time task */
 typedef int (*rt_setup_fn_t)(int pid, void* arg);
-int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg, 
+int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg,
                      rt_setup_fn_t setup, void* setup_arg);
 
 #define check(str)       \
@@ -19,3 +19,7 @@ int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg,
 
 
 #endif
+
+
+int sched_setscheduler(pid_t pid, int policy, int* prioriy);
+int sched_getscheduler(pid_t pid);
diff --git a/include/litmus.h b/include/litmus.h
index b10abff..6699213 100644
--- a/include/litmus.h
+++ b/include/litmus.h
@@ -1,7 +1,7 @@
 #ifndef LITMUS_H
 #define LITMUS_H
 
-#include <linux/rt_param.h>
+#include <litmus/rt_param.h>
 #include <sys/types.h>
 
 typedef int pid_t;       /* PID of a task */
@@ -14,7 +14,7 @@ int get_rt_task_param(pid_t pid, struct rt_task* param);
 
 /* setup helper */
 /* times are givin in ms */
-int sporadic_task(unsigned long exec_cost, unsigned long period, 
+int sporadic_task(unsigned long exec_cost, unsigned long period,
                   int partition, task_class_t cls);
 
 #define sporadic_global(e, p) \
@@ -57,7 +57,7 @@ void exit_litmus(void);
 typedef int (*rt_fn_t)(void*);
 
 int create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, int period);
-int __create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, 
+int __create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet,
                      int period, task_class_t cls);
 
 /*      per-task modes */
diff --git a/src/syscalls.c b/src/syscalls.c
index 40f5f7f..1ad709b 100644
--- a/src/syscalls.c
+++ b/src/syscalls.c
@@ -1,4 +1,4 @@
-/* To get syscall() we need to define _GNU_SOURCE 
+/* To get syscall() we need to define _GNU_SOURCE
  * in modern glibc versions.
  */
 #define _GNU_SOURCE
@@ -87,8 +87,12 @@ int wait_for_job_release(unsigned int job_no)
         return syscall(__NR_wait_for_job_release, job_no);
 }
 
-int task_mode(int target_mode)
+int sched_setscheduler(pid_t pid, int policy, int* priority)
 {
-        return syscall(__NR_task_mode, target_mode);
+        return syscall(__NR_sched_setscheduler, pid, policy, priority);
 }
 
+int sched_getscheduler(pid_t pid)
+{
+        return syscall(__NR_sched_getscheduler, pid);
+}
diff --git a/src/task.c b/src/task.c
index 7cfa6ce..0036efb 100644
--- a/src/task.c
+++ b/src/task.c
@@ -1,30 +1,31 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "litmus.h"
 #include "internal.h"
 
-static void tperrorx(char* msg) 
+static void tperrorx(char* msg)
 {
-        fprintf(stderr, 
+        fprintf(stderr,
                 "Task %d: %s: %m",
-                getpid(), msg);
+                gettid(), msg);
         exit(-1);
 }
 
 /* common launch routine */
-int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg, rt_setup_fn_t setup, 
-                     void* setup_arg) 
+int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg, rt_setup_fn_t setup,
+                     void* setup_arg)
 {
         int ret;
         int rt_task = fork();
 
         if (rt_task == 0) {
-                /* we are the real-time task 
+                /* we are the real-time task
                  * launch task and die when it is done
-                 */             
-                rt_task = getpid();             
+                 */
+                rt_task = gettid();
                 ret = setup(rt_task, setup_arg);
                 if (ret < 0)
                         tperrorx("could not setup task parameters");
@@ -38,14 +39,14 @@ int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg, rt_setup_fn_t setup,
 }
 
 int __create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, int period,
-                     task_class_t class) 
+                     task_class_t class)
 {
         struct rt_task params;
         params.cpu = cpu;
         params.period = period;
         params.exec_cost = wcet;
         params.cls = class;
-        return __launch_rt_task(rt_prog, arg, 
+        return __launch_rt_task(rt_prog, arg,
                                 (rt_setup_fn_t) set_rt_task_param, &params);
 }
 
@@ -53,3 +54,25 @@ int create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, int period) {
         return __create_rt_task(rt_prog, arg, cpu, wcet, period, RT_CLASS_HARD);
 }
 
+
+#define SCHED_NORMAL 0
+#define SCHED_LITMUS 6
+
+int task_mode(int mode)
+{
+        int prio   = 0;
+        int me     = gettid();
+        int policy = sched_getscheduler(gettid());
+        int old_mode = policy == SCHED_LITMUS ? LITMUS_RT_TASK : BACKGROUND_TASK;
+
+        if (old_mode == LITMUS_RT_TASK && mode == BACKGROUND_TASK) {
+                /* transition to normal task */
+                return sched_setscheduler(me, SCHED_NORMAL, &prio);
+        } else if (old_mode == BACKGROUND_TASK && mode == LITMUS_RT_TASK) {
+                /* transition to RT task */
+                return sched_setscheduler(me, SCHED_LITMUS, &prio);
+        } else {
+                errno = -EINVAL;
+                return -1;
+        }
+}