diff --git a/kernel/rusage.c b/kernel/rusage.c
deleted file mode 100644
index 204705cb..00000000
--- a/kernel/rusage.c
+++ /dev/null
@@ -1,400 +0,0 @@
-/**
- * \file rusage.c
- */
-#include <types.h>
-#include <kmsg.h>
-#include <ihk/cpu.h>
-#include <ihk/mm.h>
-#include <ihk/debug.h>
-#include <process.h>
-#include <init.h>
-#include <march.h>
-#include <cls.h>
-#include <time.h>
-#include <syscall.h>
-#include <string.h>
-#include <rusage.h>
-
-//#define DEBUG_PRINT_AP
-
-#ifdef DEBUG_PRINT_AP
-#define dkprintf(...) kprintf(__VA_ARGS__)
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#endif
-
-extern int num_processors ;
-static volatile int ap_stop = 1;
-
-mcs_lock_node_t ap_syscall_semaphore;
-
-extern struct ihk_os_monitor *monitor;
-
-
-#ifdef ENABLE_RUSAGE
-/* initialize rusage */
-void rusage_init() {
-	int i;
-	rusage_num_threads = 0;
-	rusage_max_num_threads = 0;
-
-	os_status = IHK_STATUS_INACTIVE;
-	rusage_hugetlb_usage = 0;
-	rusage_hugetlb_max_usage = 0;
-	for (i = 0; i < 1024; i++) {
-		rusage_numa_stat[i] = 0;
-	}
-	rusage_rss_current = 0;
-	rusage_rss_max = 0;
-}
-
-/* count total rss */
-unsigned long count_rss () {
-	return rusage_rss_current;
-}
-
-/* count total cache */
-unsigned long count_cache () {
-   return 0;
-}
-
-/* count total rss_huge */
-unsigned long count_rss_huge () {
-	return 0;
-}
-
-/* count total mapped_file */
-unsigned long count_mapped_file () {
-	return 0;
-}
-
-/* count total max_usage */
-unsigned long count_max_usage() {
-	return rusage_rss_max;
-}
-
-/* count total kmem_usage */
-unsigned long count_kmem_usage() {
-	return 0;
-}
-
-/* count total kmax_usage */
-unsigned long count_kmem_max_usage() {
-	return 0;
-}
-
-#endif 
-
-#include <sysfs.h>
-#include <vsprintf.h>
-
-#ifdef ENABLE_RUSAGE
-char* strcat_rusage(char *s1, char *s2) {
-	int i;
-	int j;
-	for (i = 0; s1[i] != '\0'; i++); //skip chars.
-	for (j = 0; s2[j] != '\0'; j++) {
-		s1[i+j] = s2[j];
-	}
-	s1[i+j] = '\0';
-	return s1;	
-}
-
-static ssize_t
-show_rusage_memory_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf, size, "rss %lu\ncache %lu\nrss_huge %lu\nmapped_file %lu\n",
-			count_rss(),
-			count_cache(),
-			count_rss_huge(),
-			count_mapped_file()
-	);
-}
-
-static ssize_t 
-show_rusage_memory_max_usage_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf,size,"%lu\n",count_max_usage());
-}
-
-static ssize_t 
-show_rusage_memory_kmem_usage_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf,size,"%lu\n",count_kmem_usage());
-}
-
-static ssize_t 
-show_rusage_memory_kmem_max_usage_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf,size,"%lu\n",count_kmem_max_usage());
-}
-
-static ssize_t 
-show_rusage_num_numa_nodes_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf,size,"%d\n",ihk_mc_get_nr_numa_nodes());
-}
-
-static ssize_t 
-show_rusage_memory_numa_stat_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	int i;
-	int num_numa;
-	char tmp_buf1[1024];
-	char tmp_buf2[1024];
-	unsigned long total = 0;
-	memset(tmp_buf1, 0, 1024);
-	num_numa = ihk_mc_get_nr_numa_nodes();
-
-	for (i = 0; i < num_numa; i++) {
-		total += rusage_numa_stat[i];
-	}
-	sprintf(tmp_buf1, "total=%lu ", total);
-
-	for (i = 0; i < num_numa; i++) {
-		sprintf(tmp_buf2, "N%d=%lu ", i, rusage_numa_stat[i]);
-		strcat_rusage(tmp_buf1, tmp_buf2);
-		memset(tmp_buf2, 0, 1024);
-	}
-	return snprintf(buf, size, "%s\n", tmp_buf1);
-}
-
-static ssize_t 
-show_rusage_hugetlb_usage_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf, size, "%lu\n", rusage_hugetlb_usage);
-}
-
-static ssize_t 
-show_rusage_hugetlb_max_usage_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf, size, "%lu\n", rusage_hugetlb_max_usage);
-}
-static ssize_t 
-show_rusage_cpuacct_stat_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	struct timespec uts;
-	struct timespec sts;
-	int i;
-	int r = 0;
-
-	uts.tv_sec = 0;
-	uts.tv_nsec = 0;
-	sts.tv_sec = 0;
-	sts.tv_nsec = 0;
-	if (monitor)
-		for (i = 0; i < num_processors; i++) {
-			struct timespec ats;
-
-			tsc_to_ts(monitor[i].user_tsc, &ats);
-			ts_add(&uts, &ats);
-			tsc_to_ts(monitor[i].system_tsc, &ats);
-			ts_add(&sts, &ats);
-		}
-	r = snprintf(buf, size, "user %lu\n", timespec_to_jiffy(&uts));
-	r += snprintf(strchr(buf, '\0'), size - r, "system %lu\n",
-				  timespec_to_jiffy(&sts));
-	return r;
-}
-static ssize_t 
-show_rusage_cpuacct_usage_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	struct timespec uts;
-	int i;
-	int r = 0;
-
-	uts.tv_sec = 0;
-	uts.tv_nsec = 0;
-	if (monitor)
-		for (i = 0; i < num_processors; i++) {
-			struct timespec ats;
-
-			tsc_to_ts(monitor[i].user_tsc + monitor[i].system_tsc,
-					  &ats);
-			ts_add(&uts, &ats);
-		}
-	if (uts.tv_sec)
-		r = snprintf(buf, size, "%lu%09lu\n", uts.tv_sec, uts.tv_nsec);
-	else
-		r = snprintf(buf, size, "%lu\n", uts.tv_nsec);
-	return r;
-}
-
-
-static ssize_t 
-show_rusage_cpuacct_usage_percpu_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	struct timespec uts;
-	int i;
-	int r = 0;
-
-	((char *)buf)[0] = '\0';
-	for (i = 0; i < num_processors; i++) {
-		if (monitor) {
-			tsc_to_ts(monitor[i].user_tsc + monitor[i].system_tsc,
-					  &uts);
-		}
-		else {
-			uts.tv_sec = 0;
-			uts.tv_nsec = 0;
-		}
-		if (uts.tv_sec)
-			r += snprintf(strchr(buf, '\0'), size - r,
-						  "%lu%09lu ", uts.tv_sec, uts.tv_nsec);
-		else
-			r += snprintf(strchr(buf, '\0'), size - r,
-						  "%lu ", uts.tv_nsec);
-	}
-	((char *)buf)[r - 1] = '\n';
-	return r;
-}
-
-/* callback funciton of rusage(threads) sysfs */
-static ssize_t
-show_rusage_num_threads_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf, size, "%lu\n", rusage_num_threads);
-}
-
-/* callback funciton of rusage(max threads) sysfs */
-static ssize_t
-show_rusage_max_num_threads_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf, size, "%lu\n", rusage_max_num_threads);
-}
-
-/* definition of sysfs ops */
-struct sysfs_ops show_rusage_memory = {
-	.show = &show_rusage_memory_data,
-};
-struct sysfs_ops show_rusage_memory_max_usage = {
-	.show = &show_rusage_memory_max_usage_data,
-};
-struct sysfs_ops show_rusage_memory_kmem_usage = {
-	.show = &show_rusage_memory_kmem_usage_data,
-};
-struct sysfs_ops show_rusage_memory_kmem_max_usage = {
-	.show = &show_rusage_memory_kmem_max_usage_data,
-};
-struct sysfs_ops show_rusage_num_numa_nodes = {
-	.show = &show_rusage_num_numa_nodes_data,
-};
-struct sysfs_ops show_rusage_memory_numa_stat = {
-	.show = &show_rusage_memory_numa_stat_data,
-};
-struct sysfs_ops show_rusage_hugetlb_usage = {
-	.show = &show_rusage_hugetlb_usage_data,
-};
-struct sysfs_ops show_rusage_hugetlb_max_usage = {
-	.show = &show_rusage_hugetlb_max_usage_data,
-};
-struct sysfs_ops show_rusage_cpuacct_stat = {
-	.show = &show_rusage_cpuacct_stat_data,
-};
-struct sysfs_ops show_rusage_cpuacct_usage = {
-	.show = &show_rusage_cpuacct_usage_data,
-};
-struct sysfs_ops show_rusage_num_threads = {
-	.show = &show_rusage_num_threads_data,
-};
-struct sysfs_ops show_rusage_cpuacct_usage_percpu = {
-	.show = &show_rusage_cpuacct_usage_percpu_data,
-};
-struct sysfs_ops show_rusage_max_num_threads = {
-	.show = &show_rusage_max_num_threads_data,
-};
-
-/* create sysfs files for rusage. */
-void rusage_sysfs_setup(void) {
-	int error;
-	error = sysfs_createf(&show_rusage_memory, &rdata, 0444,
-		"/sys/fs/cgroup/memory/memory.stat");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_memory_max_usage, &rdata, 0444,
-		"/sys/fs/cgroup/memory/memory.max_usage_in_bytes");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_memory_kmem_usage, &rdata, 0444,
-		"/sys/fs/cgroup/memory/memory.kmem.usage_in_bytes");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_memory_kmem_max_usage, &rdata, 0444,
-		"/sys/fs/cgroup/memory/memory.kmem.max_usage_in_bytes");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_num_numa_nodes, &rdata, 0444,
-		"/sys/fs/cgroup/cpu/num_numa_nodes.txt");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_memory_numa_stat, &rdata, 0444,
-		"/sys/fs/cgroup/memory/memory.numa_stat");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_hugetlb_usage, &rdata, 0444,
-		"/sys/fs/cgroup/hugetlb/hugetlb.1GB.usage_in_bytes");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_hugetlb_max_usage, &rdata, 0444,
-		"/sys/fs/cgroup/hugetlb/hugetlb.1GB.max_usage_in_bytes");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_cpuacct_stat, &rdata, 0444,
-		"/sys/fs/cgroup/cpuacct/cpuacct.stat");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_cpuacct_usage, &rdata, 0444,
-		"/sys/fs/cgroup/cpuacct/cpuacct.usage");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_cpuacct_usage_percpu, &rdata, 0444,
-		"/sys/fs/cgroup/cpuacct/cpuacct.usage_percpu");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_num_threads, &rdata, 0444,
-		"/sys/fs/cgroup/num_threads");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-	error = sysfs_createf(&show_rusage_max_num_threads, &rdata, 0444,
-		"/sys/fs/cgroup/max_num_threads");
-	if (error) {
-		panic("rusage_sysfs_setup:sysfs_createf() failed\n");
-	}
-}
-
-/* callback funciton of os_status sysfs */
-static ssize_t
-show_ihk_status_data(struct sysfs_ops *ops, void *instance, void *buf, size_t size)
-{
-	return snprintf(buf, size, "%d\n", os_status);
-}
-
-struct sysfs_ops show_ihk_status = {
-	.show = &show_ihk_status_data,
-};
-
-/* create sysfs files for monitoring status.*/
-void status_sysfs_setup(void) {
-	int error;
-	error = sysfs_createf(&show_ihk_status, &rdata, 0444,
-		"/sys/fs/cgroup/mck_status");
-	if (error) {
-		panic("status_sysfs_setup:sysfs_createf() failed\n");
-	}
-}
-#endif
-