diff --git a/runtime/Makefile b/runtime/Makefile
index c9dd3ed..f8cf33e 100644
--- a/runtime/Makefile
+++ b/runtime/Makefile
@@ -4,13 +4,15 @@ RTDIR=src/
 CFILES=${RTDIR}/*.c ${RTDIR}/libc/*.c ${RTDIR}/memory/common.c
 RUNTIME=bin/awsmrt
 INC=include/
+ARCH := $(shell uname -m)
 
 OPTFLAGS = -O3
 OPTFLAGS += -flto -g
 LDFLAGS = -Wl,--export-dynamic -ldl -lm
 USE_MEM = USE_MEM_VM
 CFLAGS = ${OPTFLAGS} -D${USE_MEM} -I${INC} -pthread
-CFLAGS += -DX86_64 
+CFLAGS += -D${ARCH}
+CFILES += ${RTDIR}/arch/${ARCH}/*.c
 #CFLAGS += -DDEBUG 
 CFLAGS += -D_GNU_SOURCE
 #CFLAGS += -DLOG_TO_FILE
diff --git a/runtime/include/arch/aarch64/context.h b/runtime/include/arch/aarch64/context.h
index 7fc2a2e..ffde16b 100644
--- a/runtime/include/arch/aarch64/context.h
+++ b/runtime/include/arch/aarch64/context.h
@@ -4,7 +4,8 @@
 #include <unistd.h>
 #include <ucontext.h>
 
-#define ARCH_NREGS 31
+#define ARCH_NREGS (2) // SP + PC only.
+#define ARCH_SIG_JMP_OFF 0x100 // Based on code generated!
 
 /**
  * ARM64 code. Currently Unimplemented
@@ -27,11 +28,86 @@ arch_context_init(arch_context_t *actx, reg_t ip, reg_t sp)
 {
 	memset(&actx->mctx, 0, sizeof(mcontext_t));
 	memset((void *)actx->regs, 0, sizeof(reg_t) * ARCH_NREGS);
+
+	*(actx->regs) = sp;
+	*(actx->regs + 1) = ip;
 }
 
+static int
+arch_mcontext_restore(mcontext_t *mc, arch_context_t *ctx)
+{
+	assert(ctx != &worker_thread_base_context);
+
+	// if ctx->regs[0] is set, this was last in a user-level context switch state!
+	// else restore mcontext..
+	if (ctx->regs[0]) {
+		mc->sp       = ctx->regs[0];
+		mc->pc       = ctx->regs[1] + ARCH_SIG_JMP_OFF;
+		ctx->regs[0] = 0;
+
+		return 1;
+	} else {
+		memcpy(mc, &ctx->mctx, sizeof(mcontext_t));
+		memset(&ctx->mctx, 0, sizeof(mcontext_t));
+	}
+
+	return 0;
+}
+
+static void
+arch_mcontext_save(arch_context_t *ctx, mcontext_t *mc)
+{
+	assert(ctx != &worker_thread_base_context);
+
+	ctx->regs[0] = 0;
+	memcpy(&ctx->mctx, mc, sizeof(mcontext_t));
+}
+
+
 static inline int
 arch_context_switch(arch_context_t *ca, arch_context_t *na)
 {
+	if (!ca) {
+		assert(na);
+		// switching from "no sandbox to execute" state to "executing a sandbox"
+		ca = &worker_thread_base_context;
+	} else if (!na) {
+		assert(ca);
+
+		// switching from "executing a sandbox" to "no execution" state.
+		na = &worker_thread_base_context;
+	} else {
+		assert(na && ca);
+
+		// switching between sandboxes.
+	}
+
+	reg_t *cr = ca->regs, *nr = na->regs;
+	assert(cr && nr);
+
+	asm volatile ( 	"mov x0, sp\n\t"
+			"adr x1, reset%=\n\t"
+			"str x1, [%[curr], 8]\n\t"
+			"str x0, [%[curr]]\n\t"
+			"ldr x2, [%[next]]\n\t"
+			"cbz x2, slow%=\n\t"
+			"ldr x3, [%[next], 8]\n\t"
+			"mov sp, x2\n\t"
+			"br x3\n\t"
+		        "slow%=:\n\t"
+			"br %[slowpath]\n\t"
+			".align 8\n\t"
+			"reset%=:\n\t"
+			"mov x1, #0\n\t"
+			"str x1, [%[next]]\n\t"
+			".align 8\n\t"
+			"exit%=:\n\t"
+			:	
+			: [curr]"r"(cr), [next]"r"(nr), [slowpath]"r"(&worker_thread_sandbox_switch_preempt)
+			: "memory", "cc", "x0", "x1", "x2", "x3",	
+			  "x4", "x5", "x6", "x7", "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
+			  "x16", "x17", "x18", "x19", "x20", "x21", "x22", "x23", "x24", "x25", "x26",
+			  "d8", "d9", "d10", "d11", "d12", "d13", "d14", "d15" );
 	return 0;
 }
 
diff --git a/runtime/include/arch/context.h b/runtime/include/arch/context.h
index e8ef2ec..ba56caf 100644
--- a/runtime/include/arch/context.h
+++ b/runtime/include/arch/context.h
@@ -1,9 +1,9 @@
 #ifndef ARCH_CONTEXT_H
 #define ARCH_CONTEXT_H
 
-#if defined(AARCH64)
+#if defined(AARCH64) || defined(aarch64)
 #include "aarch64/context.h"
-#elif defined(X86_64)
+#elif defined(X86_64) || defined(x86_64)
 #include "x86_64/context.h"
 #else
 #warning "Architecture not set. Using x86_64"
diff --git a/runtime/include/runtime.h b/runtime/include/runtime.h
index 82d005e..0ef495e 100644
--- a/runtime/include/runtime.h
+++ b/runtime/include/runtime.h
@@ -71,4 +71,6 @@ worker_thread_get_libuv_handle(void)
 	return &worker_thread_uvio_handle;
 }
 
+unsigned long long __getcycles(void);
+
 #endif /* SFRT_RUNTIME_H */
diff --git a/runtime/include/util.h b/runtime/include/util.h
deleted file mode 100644
index 0f4f1a9..0000000
--- a/runtime/include/util.h
+++ /dev/null
@@ -1,20 +0,0 @@
-#ifndef SFRT_UTIL_H
-#define SFRT_UTIL_H
-
-/**
- * Get CPU time in cycles using the Intel instruction rdtsc
- * @return CPU time in cycles
- **/
-static unsigned long long int
-util__rdtsc(void)
-{
-	unsigned long long int cpu_time_in_cycles = 0;
-	unsigned int           cycles_lo;
-	unsigned int           cycles_hi;
-	__asm__ volatile("rdtsc" : "=a"(cycles_lo), "=d"(cycles_hi));
-	cpu_time_in_cycles = (unsigned long long int)cycles_hi << 32 | cycles_lo;
-
-	return cpu_time_in_cycles;
-}
-
-#endif /* SFRT_UTIL_H */
diff --git a/runtime/src/arch/aarch64/env.c b/runtime/src/arch/aarch64/env.c
new file mode 100644
index 0000000..334288d
--- /dev/null
+++ b/runtime/src/arch/aarch64/env.c
@@ -0,0 +1,19 @@
+#if defined(AARCH64) || defined(aarch64)
+
+#include <runtime.h>
+
+unsigned long long int
+__getcycles(void)
+{
+	unsigned long long virtual_timer_value;
+	asm volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value));
+	return virtual_timer_value;
+}
+
+INLINE unsigned long long
+env_getcycles(void)
+{
+        return __getcycles();
+}
+
+#endif
diff --git a/runtime/src/arch/x86_64/env.c b/runtime/src/arch/x86_64/env.c
new file mode 100644
index 0000000..fec02f7
--- /dev/null
+++ b/runtime/src/arch/x86_64/env.c
@@ -0,0 +1,175 @@
+#if defined(X86_64) || defined(x86_64)
+
+#include <runtime.h>
+
+// Atomic functions, with definitions stolen from musl
+
+i32
+env_a_ctz_64(u64 x)
+{
+        __asm__("bsf %1,%0" : "=r"(x) : "r"(x));
+
+        return x;
+}
+
+// static inline int a_ctz_l(unsigned long x)
+//{
+//      __asm__( "bsf %1,%0" : "=r"(x) : "r"(x) );
+//      return x;
+//}
+
+INLINE void
+env_a_and_64(i32 p_off, u64 v)
+{
+        uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(uint64_t));
+        *p &= v;
+
+        //      __asm__( "lock ; and %1, %0"
+        //                       : "=m"(*p) : "r"(v) : "memory" );
+}
+
+INLINE void
+env_a_or_64(i32 p_off, i64 v)
+{
+        assert(sizeof(i64) == sizeof(uint64_t));
+        uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i64));
+        *p |= v;
+
+        //      __asm__( "lock ; or %1, %0"
+        //                       : "=m"(*p) : "r"(v) : "memory" );
+}
+
+// static inline void a_or_l(volatile void *p, long v)
+//{
+//      __asm__( "lock ; or %1, %0"
+//              : "=m"(*(long *)p) : "r"(v) : "memory" );
+//}
+//
+// static inline void *a_cas_p(volatile void *p, void *t, void *s)
+//{
+//      __asm__( "lock ; cmpxchg %3, %1"
+//              : "=a"(t), "=m"(*(long *)p) : "a"(t), "r"(s) : "memory" );
+//      return t;
+//}
+//
+i32
+env_a_cas(i32 p_off, i32 t, i32 s)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
+
+        __asm__("lock ; cmpxchg %3, %1" : "=a"(t), "=m"(*p) : "a"(t), "r"(s) : "memory");
+
+        return t;
+}
+
+void
+env_a_or(i32 p_off, i32 v)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
+        __asm__("lock ; or %1, %0" : "=m"(*p) : "r"(v) : "memory");
+}
+
+// static inline void a_and(volatile int *p, int v)
+//{
+//      __asm__( "lock ; and %1, %0"
+//              : "=m"(*p) : "r"(v) : "memory" );
+//}
+
+
+i32
+env_a_swap(i32 x_off, i32 v)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+
+        __asm__("xchg %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory");
+
+        return v;
+}
+
+i32
+env_a_fetch_add(i32 x_off, i32 v)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+
+        __asm__("lock ; xadd %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory");
+
+        return v;
+}
+
+void
+env_a_inc(i32 x_off)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+
+        __asm__("lock ; incl %0" : "=m"(*x) : "m"(*x) : "memory");
+}
+
+void
+env_a_dec(i32 x_off)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+
+        __asm__("lock ; decl %0" : "=m"(*x) : "m"(*x) : "memory");
+}
+
+
+void
+env_a_store(i32 p_off, i32 x)
+{
+        assert(sizeof(i32) == sizeof(volatile int));
+        volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
+        __asm__ __volatile__("mov %1, %0 ; lock ; orl $0,(%%esp)" : "=m"(*p) : "r"(x) : "memory");
+}
+
+void
+env_do_spin(i32 i)
+{
+        __asm__ __volatile__("pause" : : : "memory");
+}
+
+void
+env_do_crash(i32 i)
+{
+        printf("crashing: %d\n", i);
+        assert(0);
+}
+
+int
+env_a_ctz_32(i32 x)
+{
+        __asm__("bsf %1,%0" : "=r"(x) : "r"(x));
+
+        return x;
+}
+
+void
+env_do_barrier(i32 x)
+{
+        __asm__ __volatile__("" : : : "memory");
+}
+
+unsigned long long int
+__getcycles(void)
+{
+        unsigned long long int cpu_time_in_cycles = 0;
+        unsigned int           cycles_lo;
+        unsigned int           cycles_hi;
+        __asm__ volatile("rdtsc" : "=a"(cycles_lo), "=d"(cycles_hi));
+        cpu_time_in_cycles = (unsigned long long int)cycles_hi << 32 | cycles_lo;
+
+        return cpu_time_in_cycles;
+}
+
+INLINE unsigned long long
+env_getcycles(void)
+{
+        return __getcycles();
+}
+
+#endif
diff --git a/runtime/src/env.c b/runtime/src/env.c
index df80da8..128b9e6 100644
--- a/runtime/src/env.c
+++ b/runtime/src/env.c
@@ -1,6 +1,5 @@
 /* https://github.com/gwsystems/silverfish/blob/master/runtime/libc/libc_backing.c */
 #include <runtime.h>
-#include <util.h>
 
 extern i32 inner_syscall_handler(i32 n, i32 a, i32 b, i32 c, i32 d, i32 e, i32 f);
 
@@ -18,156 +17,6 @@ env___syscall(i32 n, i32 a, i32 b, i32 c, i32 d, i32 e, i32 f)
 	return env_syscall_handler(n, a, b, c, d, e, f);
 }
 
-// Atomic functions, with definitions stolen from musl
-
-i32
-env_a_ctz_64(u64 x)
-{
-	__asm__("bsf %1,%0" : "=r"(x) : "r"(x));
-
-	return x;
-}
-
-// static inline int a_ctz_l(unsigned long x)
-//{
-//	__asm__( "bsf %1,%0" : "=r"(x) : "r"(x) );
-//	return x;
-//}
-
-INLINE void
-env_a_and_64(i32 p_off, u64 v)
-{
-	uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(uint64_t));
-	*p &= v;
-
-	//	__asm__( "lock ; and %1, %0"
-	//			 : "=m"(*p) : "r"(v) : "memory" );
-}
-
-INLINE void
-env_a_or_64(i32 p_off, i64 v)
-{
-	assert(sizeof(i64) == sizeof(uint64_t));
-	uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i64));
-	*p |= v;
-
-	//	__asm__( "lock ; or %1, %0"
-	//			 : "=m"(*p) : "r"(v) : "memory" );
-}
-
-// static inline void a_or_l(volatile void *p, long v)
-//{
-//	__asm__( "lock ; or %1, %0"
-//		: "=m"(*(long *)p) : "r"(v) : "memory" );
-//}
-//
-// static inline void *a_cas_p(volatile void *p, void *t, void *s)
-//{
-//	__asm__( "lock ; cmpxchg %3, %1"
-//		: "=a"(t), "=m"(*(long *)p) : "a"(t), "r"(s) : "memory" );
-//	return t;
-//}
-//
-i32
-env_a_cas(i32 p_off, i32 t, i32 s)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
-
-	__asm__("lock ; cmpxchg %3, %1" : "=a"(t), "=m"(*p) : "a"(t), "r"(s) : "memory");
-
-	return t;
-}
-
-void
-env_a_or(i32 p_off, i32 v)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
-	__asm__("lock ; or %1, %0" : "=m"(*p) : "r"(v) : "memory");
-}
-
-// static inline void a_and(volatile int *p, int v)
-//{
-//	__asm__( "lock ; and %1, %0"
-//		: "=m"(*p) : "r"(v) : "memory" );
-//}
-
-i32
-env_a_swap(i32 x_off, i32 v)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-
-	__asm__("xchg %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory");
-
-	return v;
-}
-
-i32
-env_a_fetch_add(i32 x_off, i32 v)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-
-	__asm__("lock ; xadd %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory");
-
-	return v;
-}
-
-void
-env_a_inc(i32 x_off)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-
-	__asm__("lock ; incl %0" : "=m"(*x) : "m"(*x) : "memory");
-}
-
-void
-env_a_dec(i32 x_off)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-
-	__asm__("lock ; decl %0" : "=m"(*x) : "m"(*x) : "memory");
-}
-
-void
-env_a_store(i32 p_off, i32 x)
-{
-	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
-	__asm__ __volatile__("mov %1, %0 ; lock ; orl $0,(%%esp)" : "=m"(*p) : "r"(x) : "memory");
-}
-
-void
-env_do_spin(i32 i)
-{
-	__asm__ __volatile__("pause" : : : "memory");
-}
-
-void
-env_do_crash(i32 i)
-{
-	printf("crashing: %d\n", i);
-	assert(0);
-}
-
-int
-env_a_ctz_32(i32 x)
-{
-	__asm__("bsf %1,%0" : "=r"(x) : "r"(x));
-
-	return x;
-}
-
-void
-env_do_barrier(i32 x)
-{
-	__asm__ __volatile__("" : : : "memory");
-}
-
 
 void
 env___unmapself(u32 base, u32 size)
@@ -189,8 +38,3 @@ env_cos(double d)
 	return cos(d);
 }
 
-INLINE unsigned long long
-env_rdtsc(void)
-{
-	return util__rdtsc();
-}
diff --git a/runtime/src/main.c b/runtime/src/main.c
index 744be41..417acc4 100644
--- a/runtime/src/main.c
+++ b/runtime/src/main.c
@@ -87,7 +87,7 @@ runtime_allocate_available_cores()
 		runtime_first_worker_processor  = 0;
 		runtime_total_worker_processors = 1;
 	}
-	debuglog("Number of cores %u, sandboxing cores %u (start: %u) and module reqs %u\n",
+	printf("Number of cores %u, sandboxing cores %u (start: %u) and module reqs %u\n",
 	         runtime_total_online_processors, runtime_total_worker_processors, runtime_first_worker_processor,
 	         LISTENER_THREAD__CORE_ID);
 }
@@ -138,6 +138,7 @@ runtime_start_runtime_worker_threads()
 		assert(ret == 0);
 	}
 	debuglog("Sandboxing environment ready!\n");
+	printf("aWsm runtime ready!\n");
 
 	for (int i = 0; i < runtime_total_worker_processors; i++) {
 		int ret = pthread_join(runtime_worker_threads[i], NULL);
@@ -159,7 +160,7 @@ main(int argc, char **argv)
 	runtime_process_debug_log_behavior();
 #endif
 
-	printf("Starting Awsm\n");
+	printf("Initializing the runtime\n");
 	if (argc != 2) {
 		runtime_usage(argv[0]);
 		exit(-1);
@@ -177,6 +178,8 @@ main(int argc, char **argv)
 		exit(-1);
 	}
 
+	printf("Starting listener thread\n");
 	listener_thread_initialize();
+	printf("Starting worker threads\n");
 	runtime_start_runtime_worker_threads();
 }
diff --git a/runtime/src/module.c b/runtime/src/module.c
index 2acd33a..51e2109 100644
--- a/runtime/src/module.c
+++ b/runtime/src/module.c
@@ -7,7 +7,6 @@
 #include <module.h>
 #include <module_database.h>
 #include <runtime.h>
-#include <util.h>
 
 /***************************************
  * Private Static Inline
@@ -269,7 +268,6 @@ module_new_from_json(char *file_name)
 				is_active = (strcmp(val, "yes") == 0);
 			} else if (strcmp(key, "relative-deadline-us") == 0) {
 				relative_deadline_us = atoi(val);
-				printf("Set relative deadline to %d us\n", relative_deadline_us);
 			} else if (strcmp(key, "http-req-headers") == 0) {
 				assert(tokens[i + j + 1].type == JSMN_ARRAY);
 				assert(tokens[i + j + 1].size <= HTTP__MAX_HEADER_COUNT);
@@ -329,4 +327,4 @@ module_new_from_json(char *file_name)
 	debuglog("Loaded %d module%s!\n", module_count, module_count > 1 ? "s" : "");
 
 	return 0;
-}
\ No newline at end of file
+}
diff --git a/runtime/src/runtime.c b/runtime/src/runtime.c
index ac1a4b8..dbf1cf0 100644
--- a/runtime/src/runtime.c
+++ b/runtime/src/runtime.c
@@ -22,7 +22,6 @@
 #include <sandbox_request.h>
 #include <software_interrupt.h>
 #include <types.h>
-#include <util.h>
 
 /***************************
  * Shared Process State    *
@@ -84,7 +83,7 @@ listener_thread_main(void *dummy)
 	while (true) {
 		int request_count = epoll_wait(runtime_epoll_file_descriptor, epoll_events,
 		                               LISTENER_THREAD__MAX_EPOLL_EVENTS, -1);
-		u64 start_time    = util__rdtsc();
+		u64 start_time    = __getcycles();
 		for (int i = 0; i < request_count; i++) {
 			if (epoll_events[i].events & EPOLLERR) {
 				perror("epoll_wait");
@@ -102,7 +101,6 @@ listener_thread_main(void *dummy)
 				assert(0);
 			}
 			total_requests++;
-			printf("Received Request %d at %lu\n", total_requests, start_time);
 
 			sandbox_request_t *sandbox_request =
 			  sandbox_request__allocate(module, module->name, socket_descriptor,
@@ -254,7 +252,8 @@ worker_thread_process_io(void)
 /**
  * TODO: What is this doing?
  **/
-void __attribute__((noinline)) __attribute__((noreturn)) worker_thread_sandbox_switch_preempt(void)
+void __attribute__((noinline)) __attribute__((noreturn))
+worker_thread_sandbox_switch_preempt(void)
 {
 	pthread_kill(pthread_self(), SIGUSR1);
 
@@ -468,4 +467,4 @@ worker_thread_exit_current_sandbox(void)
 	// unmap linear memory only!
 	munmap(current_sandbox->linear_memory_start, SBOX_MAX_MEM + PAGE_SIZE);
 	worker_thread_switch_to_sandbox(next_sandbox);
-}
\ No newline at end of file
+}
diff --git a/runtime/src/sandbox.c b/runtime/src/sandbox.c
index 7b0cda5..35c1838 100644
--- a/runtime/src/sandbox.c
+++ b/runtime/src/sandbox.c
@@ -6,7 +6,6 @@
 #include <signal.h>
 #include <uv.h>
 #include <libuv_callbacks.h>
-#include <util.h>
 #include <current_sandbox.h>
 
 /**
@@ -140,8 +139,7 @@ current_sandbox_build_and_send_client_response(void)
 done:
 	assert(sndsz == curr->request_response_data_length);
 	// Get End Timestamp
-	curr->total_time = util__rdtsc() - curr->start_time;
-	printf("Function returned in %lu cycles\n", curr->total_time);
+	curr->total_time = __getcycles() - curr->start_time;
 
 #ifndef USE_HTTP_UVIO
 	int r = send(curr->client_socket_descriptor, curr->request_response_data, sndsz, 0);
diff --git a/runtime/tests/work/main.c b/runtime/tests/work/main.c
index e4d62e0..bf42a16 100644
--- a/runtime/tests/work/main.c
+++ b/runtime/tests/work/main.c
@@ -13,9 +13,9 @@ main(void)
 	char *d = malloc(MAX_BUF + 1);
 	int   r = read(0, d, MAX_BUF);
 
-	//	unsigned long long st = util__rdtsc(), en = 0;
+	//	unsigned long long st = getcycles(), en = 0;
 	//	wrk();
-	//	en = util__rdtsc();
+	//	en = getcycles();
 
 	//	if (r <= 0) printf("%llu\n", en > st ? (en - st)/CPU_CYCS : -1);
 	if (r < 0)
diff --git a/runtime/tests/work100k/main.c b/runtime/tests/work100k/main.c
index 375ff7e..dd9cfa7 100644
--- a/runtime/tests/work100k/main.c
+++ b/runtime/tests/work100k/main.c
@@ -11,9 +11,9 @@ main(void)
 	char *d = malloc(MAX_BUF + 1);
 	int   r = read(0, d, MAX_BUF);
 
-	//	unsigned long long st = util__rdtsc(), en = 0;
+	//	unsigned long long st = getcycles(), en = 0;
 	//	wrk();
-	//	en = util__rdtsc();
+	//	en = getcycles();
 
 	//	if (r <= 0) printf("%llu\n", en > st ? (en - st)/CPU_CYCS : -1);
 	if (r < 0)
diff --git a/runtime/tests/work10k/main.c b/runtime/tests/work10k/main.c
index 6370306..f456ccc 100644
--- a/runtime/tests/work10k/main.c
+++ b/runtime/tests/work10k/main.c
@@ -11,9 +11,9 @@ main(void)
 	char *d = malloc(MAX_BUF + 1);
 	int   r = read(0, d, MAX_BUF);
 
-	//	unsigned long long st = util__rdtsc(), en = 0;
+	//	unsigned long long st = getcycles(), en = 0;
 	//	wrk();
-	//	en = util__rdtsc();
+	//	en = getcycles();
 
 	//	if (r <= 0) printf("%llu\n", en > st ? (en - st)/CPU_CYCS : -1);
 	if (r < 0)
diff --git a/runtime/tests/work1k/main.c b/runtime/tests/work1k/main.c
index ed56018..1c76d4d 100644
--- a/runtime/tests/work1k/main.c
+++ b/runtime/tests/work1k/main.c
@@ -11,9 +11,9 @@ main(void)
 	char *d = malloc(MAX_BUF + 1);
 	int   r = read(0, d, MAX_BUF);
 
-	//	unsigned long long st = util__rdtsc(), en = 0;
+	//	unsigned long long st = getcycles(), en = 0;
 	//	wrk();
-	//	en = util__rdtsc();
+	//	en = getcycles();
 
 	//	if (r <= 0) printf("%llu\n", en > st ? (en - st)/CPU_CYCS : -1);
 	if (r < 0)
diff --git a/runtime/tests/work1m/main.c b/runtime/tests/work1m/main.c
index 4f7f070..0c40471 100644
--- a/runtime/tests/work1m/main.c
+++ b/runtime/tests/work1m/main.c
@@ -11,9 +11,9 @@ main(void)
 	char *d = malloc(MAX_BUF + 1);
 	int   r = read(0, d, MAX_BUF);
 
-	//	unsigned long long st = util__rdtsc(), en = 0;
+	//	unsigned long long st = getcycles(), en = 0;
 	//	wrk();
-	//	en = util__rdtsc();
+	//	en = getcycles();
 
 	//	if (r <= 0) printf("%llu\n", en > st ? (en - st)/CPU_CYCS : -1);
 	if (r < 0)
diff --git a/silverfish b/silverfish
index 507ef4b..a44fe45 160000
--- a/silverfish
+++ b/silverfish
@@ -1 +1 @@
-Subproject commit 507ef4b2a14f45ccb246a202b485d175116e0b80
+Subproject commit a44fe4566e1cca6fba95852e077311e5d3e21226