Merge branch 'lukas/erts/msacc'

* lukas/erts/msacc:
  Update preloaded modules
  erts: Make msacc alloctor type thread safe
  Silence compiler
  erts: Fix msacc testcase on some windowses
  erts: Add power saving cpu feature tests and use them
  erts: Refactor perf counter internal interface
  erts: Add rdtscp instruction check
  erts: Fix hrtime for windows
  erts: use correct function for perf counter on non-x86
  erts: Fix msacc win32 debug compile error
  erts: Add microstate accounting
  erts, kernel: Add os:perf_counter function
  erts: Add ERTS_WRITE_UNLIKELY

25 files changed, 1265 insertions, 41 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 1629a92aa9..6fb08ee896 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -102,6 +102,7 @@ atom asynchronous
 atom atom
 atom atom_used
 atom attributes
+atom await_microstate_accounting_modifications
 atom await_port_send_result
 atom await_proc_exit
 atom await_result
@@ -172,6 +173,7 @@ atom const
 atom context_switches
 atom control
 atom copy
+atom counters
 atom cpu
 atom cpu_timestamp
 atom cr
@@ -269,6 +271,7 @@ atom get_tcw
 atom getenv
 atom gather_gc_info_result
 atom gather_io_bytes
+atom gather_microstate_accounting_result
 atom gather_sched_wall_time_result
 atom getting_linked
 atom getting_unlinked
@@ -360,6 +363,7 @@ atom merge_trap
 atom meta
 atom meta_match_spec
 atom micro_seconds
+atom microstate_accounting
 atom milli_seconds
 atom min_heap_size
 atom min_bin_vheap_size
diff --git a/erts/emulator/beam/beam_bp.c b/erts/emulator/beam/beam_bp.c
index 2a23da4f25..5d471d168b 100644
--- a/erts/emulator/beam/beam_bp.c
+++ b/erts/emulator/beam/beam_bp.c
@@ -864,7 +864,7 @@ do_call_trace(Process* c_p, BeamInstr* I, Eterm* reg,
     Eterm* cpp;
     int return_to_trace = 0;
     BeamInstr w;
-    BeamInstr *cp_save;
+    BeamInstr *cp_save = c_p->cp;
     Uint32 flags;
     Uint need = 0;
     Eterm* E = c_p->stop;
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index b807102aa0..d4fb36acc3 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -113,6 +113,9 @@ do {                                     \
 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
 #endif
 
+#define GET_BIF_MODULE(p)  ((Eterm) (((Export *) p)->code[0]))
+#define GET_BIF_FUNCTION(p)  ((Eterm) (((Export *) p)->code[1]))
+#define GET_BIF_ARITY(p)  ((Eterm) (((Export *) p)->code[2]))
 #define GET_BIF_ADDRESS(p) ((BifFunction) (((Export *) p)->code[4]))
 #define TermWords(t) (((t) / (sizeof(BeamInstr)/sizeof(Eterm))) + !!((t) % (sizeof(BeamInstr)/sizeof(Eterm))))
 
@@ -1249,6 +1252,8 @@ void process_main(void)
     Uint64 start_time = 0;          /* Monitor long schedule */
     BeamInstr* start_time_i = NULL;
 
+    ERTS_MSACC_DECLARE_CACHE_X() /* a cached value of the tsd pointer for msacc */
+
     ERL_BITS_DECLARE_STATEP; /* Has to be last declaration */
 
 
@@ -1302,6 +1307,8 @@ void process_main(void)
     ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
     PROCESS_MAIN_CHK_LOCKS(c_p);
 
+    ERTS_MSACC_UPDATE_CACHE_X();
+
     if (erts_system_monitor_long_schedule != 0) {
 	start_time = erts_timestamp_millis();
 	start_time_i = c_p->i;
@@ -2741,11 +2748,21 @@ do {						\
      */
  OpCase(call_bif_e):
     {
-	Eterm (*bf)(Process*, Eterm*, BeamInstr*) = GET_BIF_ADDRESS(Arg(0));
+        Eterm (*bf)(Process*, Eterm*, BeamInstr*);
 	Eterm result;
 	BeamInstr *next;
 	ErlHeapFragment *live_hf_end;
 
+        if (ERTS_MSACC_IS_ENABLED_CACHED_X()) {
+            if (GET_BIF_MODULE(Arg(0)) == am_ets) {
+                ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_ETS);
+            } else {
+                ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_BIF);
+            }
+        }
+
+	bf = GET_BIF_ADDRESS(Arg(0));
+
 	PRE_BIF_SWAPOUT(c_p);
 	c_p->fcalls = FCALLS - 1;
 	if (FCALLS <= 0) {
@@ -2768,6 +2785,12 @@ do {						\
 	PROCESS_MAIN_CHK_LOCKS(c_p);
 	HTOP = HEAP_TOP(c_p);
 	FCALLS = c_p->fcalls;
+        /* We have to update the cache if we are enabled in order
+           to make sure no book keeping is done after we disabled
+           msacc. We don't always do this as it is quite expensive. */
+        if (ERTS_MSACC_IS_ENABLED_CACHED_X())
+            ERTS_MSACC_UPDATE_CACHE_X();
+	ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
 	if (is_value(result)) {
 	    r(0) = result;
 	    CHECK_TERM(r(0));
@@ -3452,6 +3475,8 @@ do {						\
 	    BifFunction vbf;
 	    ErlHeapFragment *live_hf_end;
 
+	    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_NIF);
+
 	    DTRACE_NIF_ENTRY(c_p, (Eterm)I[-3], (Eterm)I[-2], (Uint)I[-1]);
 	    c_p->current = I-3; /* current and vbf set to please handle_error */ 
 	    SWAPOUT;
@@ -3476,6 +3501,8 @@ do {						\
 	    PROCESS_MAIN_CHK_LOCKS(c_p);
 	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 
+	    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
+
 	    DTRACE_NIF_RETURN(c_p, (Eterm)I[-3], (Eterm)I[-2], (Uint)I[-1]);
 	    goto apply_bif_or_nif_epilogue;
 	 
@@ -3490,6 +3517,13 @@ do {						\
 	     * code[3]: &&apply_bif
 	     * code[4]: Function pointer to BIF function
 	     */
+            if (ERTS_MSACC_IS_ENABLED_CACHED_X()) {
+                if ((Eterm)I[-3] == am_ets) {
+                    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_ETS);
+                } else {
+                    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_BIF);
+                }
+            }
 
 	    c_p->current = I-3;	/* In case we apply process_info/1,2 or load_nif/1 */
 	    c_p->i = I;		/* In case we apply check_process_code/2. */
@@ -3516,7 +3550,12 @@ do {						\
 		ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 		PROCESS_MAIN_CHK_LOCKS(c_p);
 	    }
-
+            /* We have to update the cache if we are enabled in order
+               to make sure no book keeping is done after we disabled
+               msacc. We don't always do this as it is quite expensive. */
+            if (ERTS_MSACC_IS_ENABLED_CACHED_X())
+                ERTS_MSACC_UPDATE_CACHE_X();
+	    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
 	    DTRACE_BIF_RETURN(c_p, (Eterm)I[-3], (Eterm)I[-2], (Uint)I[-1]);
 
 	apply_bif_or_nif_epilogue:
@@ -4895,6 +4934,38 @@ do {						\
      }
  }
 
+ /* This is optimised as an instruction because
+    it has to be very very fast */
+ OpCase(i_perf_counter): {
+    BeamInstr* next;
+    ErtsSysPerfCounter ts;
+    PreFetch(0, next);
+
+    ts = erts_sys_perf_counter();
+
+    if (IS_SSMALL(ts)) {
+        r(0) = make_small((Sint)ts);
+    } else {
+        TestHeap(ERTS_SINT64_HEAP_SIZE(ts),0);
+        r(0) = make_big(HTOP);
+#if defined(ARCH_32) || HALFWORD_HEAP
+        if (ts >= (((Uint64) 1) << 32)) {
+            *HTOP = make_pos_bignum_header(2);
+            BIG_DIGIT(HTOP, 0) = (Uint) (ts & ((Uint) 0xffffffff));
+            BIG_DIGIT(HTOP, 1) = (Uint) ((ts >> 32) & ((Uint) 0xffffffff));
+            HTOP += 3;
+        }
+        else
+#endif
+        {
+                *HTOP = make_pos_bignum_header(1);
+                BIG_DIGIT(HTOP, 0) = (Uint) ts;
+                HTOP += 2;
+        }
+    }
+    NextPF(0, next);
+ }
+
  OpCase(i_debug_breakpoint): {
      HEAVY_SWAPOUT;
      I = call_error_handler(c_p, I-3, reg, am_breakpoint);
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index bb9165cd79..7e8eb44680 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -44,6 +44,7 @@
 #include "erl_ptab.h"
 #include "erl_bits.h"
 #include "erl_bif_unique.h"
+#include "erl_msacc.h"
 
 Export *erts_await_result;
 static Export* flush_monitor_messages_trap = NULL;
@@ -54,6 +55,9 @@ Export* erts_format_cpu_topology_trap = NULL;
 static Export dsend_continue_trap_export;
 Export *erts_convert_time_unit_trap = NULL;
 
+static Export *await_msacc_mod_trap = NULL;
+static erts_smp_atomic32_t msacc;
+
 static Export *await_sched_wall_time_mod_trap;
 static erts_smp_atomic32_t sched_wall_time;
 
@@ -2143,7 +2147,11 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     int connect = !0;
     Eterm l = opts;
     Sint result;
+
     DeclareTypedTmpHeap(ErtsSendContext, ctx, BIF_P);
+
+    ERTS_MSACC_PUSH_STATE_M_X();
+
     UseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), BIF_P);
 
     ctx->suspend = !0;
@@ -2172,7 +2180,10 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     ref = NIL;
 #endif
 
+    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_SEND);
     result = do_send(p, to, msg, &ref, ctx);
+    ERTS_MSACC_POP_STATE_M_X();
+
     if (result > 0) {
 	ERTS_VBUMP_REDS(p, result);
 	if (ERTS_IS_PROC_OUT_OF_REDS(p))
@@ -2288,8 +2299,8 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
     Eterm ref;
     Sint result;
     DeclareTypedTmpHeap(ErtsSendContext, ctx, p);
+    ERTS_MSACC_PUSH_AND_SET_STATE_M_X(ERTS_MSACC_STATE_SEND);
     UseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), p);
-
 #ifdef DEBUG
     ref = NIL;
 #endif
@@ -2300,7 +2311,9 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
     ctx->dss.phase = ERTS_DSIG_SEND_PHASE_INIT;
 
     result = do_send(p, to, msg, &ref, ctx);
-    
+
+    ERTS_MSACC_POP_STATE_M_X();
+
     if (result > 0) {
 	ERTS_VBUMP_REDS(p, result);
 	if (ERTS_IS_PROC_OUT_OF_REDS(p))
@@ -4586,6 +4599,31 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
 	default:
 	    ERTS_INTERNAL_ERROR("Unknown state");
 	}
+#ifdef ERTS_ENABLE_MSACC
+    } else if (BIF_ARG_1 == am_microstate_accounting) {
+      Eterm threads;
+      if (BIF_ARG_2 == am_true || BIF_ARG_2 == am_false) {
+        erts_aint32_t new = BIF_ARG_2 == am_true ? ERTS_MSACC_ENABLE : ERTS_MSACC_DISABLE;
+	erts_aint32_t old = erts_smp_atomic32_xchg_nob(&msacc, new);
+	Eterm ref = erts_msacc_request(BIF_P, new, &threads);
+        if (is_non_value(ref))
+            BIF_RET(old ? am_true : am_false);
+	BIF_TRAP3(await_msacc_mod_trap,
+		  BIF_P,
+		  ref,
+		  old ? am_true : am_false,
+		  threads);
+      } else if (BIF_ARG_2 == am_reset) {
+	Eterm ref = erts_msacc_request(BIF_P, ERTS_MSACC_RESET, &threads);
+	erts_aint32_t old = erts_smp_atomic32_read_nob(&msacc);
+	ASSERT(is_value(ref));
+	BIF_TRAP3(await_msacc_mod_trap,
+		  BIF_P,
+		  ref,
+		  old ? am_true : am_false,
+		  threads);
+      }
+#endif
     } else if (ERTS_IS_ATOM_STR("scheduling_statistics", BIF_ARG_1)) {
 	int what;
 	if (ERTS_IS_ATOM_STR("disable", BIF_ARG_2))
@@ -4915,8 +4953,12 @@ void erts_init_bif(void)
     await_port_send_result_trap
 	= erts_export_put(am_erts_internal, am_await_port_send_result, 3);
     await_sched_wall_time_mod_trap
-	= erts_export_put(am_erlang, am_await_sched_wall_time_modifications, 2);
+        = erts_export_put(am_erlang, am_await_sched_wall_time_modifications, 2);
+    await_msacc_mod_trap
+	= erts_export_put(am_erts_internal, am_await_microstate_accounting_modifications, 3);
+
     erts_smp_atomic32_init_nob(&sched_wall_time, 0);
+    erts_smp_atomic32_init_nob(&msacc, ERTS_MSACC_IS_ENABLED());
 }
 
 #ifdef HARDDEBUG
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 1b8ae8cef5..4efc055aaf 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -170,6 +170,7 @@ bif erts_internal:term_type/1
 bif erts_internal:map_hashmap_children/1
 
 bif erts_internal:time_unit/0
+bif erts_internal:perf_counter_unit/0
 
 bif erts_internal:is_system_process/1
 
@@ -369,6 +370,7 @@ bif os:getpid/0
 bif os:timestamp/0
 bif os:system_time/0
 bif os:system_time/1
+bif os:perf_counter/0
 
 #
 # Bifs in the erl_ddll module (the module actually does not exist)
diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 5544712e8d..51b522c9e0 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -103,9 +103,9 @@ static Uint install_debug_functions(void);
 
 static int lock_all_physical_memory = 0;
 
-ErtsAllocatorFunctions_t erts_allctrs[ERTS_ALC_A_MAX+1];
+ErtsAllocatorFunctions_t ERTS_WRITE_UNLIKELY(erts_allctrs[ERTS_ALC_A_MAX+1]);
 ErtsAllocatorInfo_t erts_allctrs_info[ERTS_ALC_A_MAX+1];
-ErtsAllocatorThrSpec_t erts_allctr_thr_spec[ERTS_ALC_A_MAX+1];
+ErtsAllocatorThrSpec_t ERTS_WRITE_UNLIKELY(erts_allctr_thr_spec[ERTS_ALC_A_MAX+1]);
 
 #define ERTS_MIN(A, B) ((A) < (B) ? (A) : (B))
 #define ERTS_MAX(A, B) ((A) > (B) ? (A) : (B))
diff --git a/erts/emulator/beam/erl_alloc.h b/erts/emulator/beam/erl_alloc.h
index 14e80960f5..71e4713624 100644
--- a/erts/emulator/beam/erl_alloc.h
+++ b/erts/emulator/beam/erl_alloc.h
@@ -233,12 +233,14 @@ ERTS_ALC_INLINE
 void *erts_alloc(ErtsAlcType_t type, Uint size)
 {
     void *res;
+    ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     res = (*erts_allctrs[ERTS_ALC_T2A(type)].alloc)(
 	ERTS_ALC_T2N(type),
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	size);
     if (!res)
 	erts_alloc_n_enomem(ERTS_ALC_T2N(type), size);
+    ERTS_MSACC_POP_STATE_X();
     return res;
 }
 
@@ -246,6 +248,7 @@ ERTS_ALC_INLINE
 void *erts_realloc(ErtsAlcType_t type, void *ptr, Uint size)
 {
     void *res;
+    ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     res = (*erts_allctrs[ERTS_ALC_T2A(type)].realloc)(
 	ERTS_ALC_T2N(type),
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
@@ -253,37 +256,48 @@ void *erts_realloc(ErtsAlcType_t type, void *ptr, Uint size)
 	size);
     if (!res)
 	erts_realloc_n_enomem(ERTS_ALC_T2N(type), ptr, size);
+    ERTS_MSACC_POP_STATE_X();
     return res;
 }
 
 ERTS_ALC_INLINE
 void erts_free(ErtsAlcType_t type, void *ptr)
 {
+    ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     (*erts_allctrs[ERTS_ALC_T2A(type)].free)(
 	ERTS_ALC_T2N(type),
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	ptr);
+    ERTS_MSACC_POP_STATE_X();
 }
 
 
 ERTS_ALC_INLINE
 void *erts_alloc_fnf(ErtsAlcType_t type, Uint size)
 {
-    return (*erts_allctrs[ERTS_ALC_T2A(type)].alloc)(
+    void *res;
+    ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
+    res = (*erts_allctrs[ERTS_ALC_T2A(type)].alloc)(
 	ERTS_ALC_T2N(type),
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	size);
+    ERTS_MSACC_POP_STATE_X();
+    return res;
 }
 
 
 ERTS_ALC_INLINE
 void *erts_realloc_fnf(ErtsAlcType_t type, void *ptr, Uint size)
 {
-    return (*erts_allctrs[ERTS_ALC_T2A(type)].realloc)(
+    void *res;
+    ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
+    res = (*erts_allctrs[ERTS_ALC_T2A(type)].realloc)(
 	ERTS_ALC_T2N(type),
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	ptr,
 	size);
+    ERTS_MSACC_POP_STATE_X();
+    return res;
 }
 
 ERTS_ALC_INLINE
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index e0bc71c88a..5f153ac0ab 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -361,6 +361,7 @@ type	AINFO_REQ	SHORT_LIVED	SYSTEM		alloc_info_request
 type	SCHED_WTIME_REQ	SHORT_LIVED	SYSTEM		sched_wall_time_request
 type	GC_INFO_REQ	SHORT_LIVED	SYSTEM		gc_info_request
 type	PORT_DATA_HEAP	STANDARD	SYSTEM		port_data_heap
+type    MSACC           DRIVER          SYSTEM          microstate_accounting
 
 #
 # Types used by system specific code
diff --git a/erts/emulator/beam/erl_async.c b/erts/emulator/beam/erl_async.c
index be0bc0cfec..cdeeb5281b 100644
--- a/erts/emulator/beam/erl_async.c
+++ b/erts/emulator/beam/erl_async.c
@@ -400,13 +400,19 @@ static ERTS_INLINE void call_async_ready(ErtsAsync *a)
 				     ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
 #endif
     if (!p) {
-	if (a->async_free)
+	if (a->async_free) {
+            ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_PORT);
 	    a->async_free(a->async_data);
+            ERTS_MSACC_POP_STATE();
+        }
     }
     else {
 	if (async_ready(p, a->async_data)) {
-	    if (a->async_free)
+	    if (a->async_free) {
+                ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_PORT);
 		a->async_free(a->async_data);
+                ERTS_MSACC_POP_STATE();
+            }
 	}
 #if ERTS_USE_ASYNC_READY_Q
 	erts_port_release(p);
@@ -460,6 +466,8 @@ static erts_tse_t *async_thread_init(ErtsAsyncQ *aq)
 {
     ErtsThrQInit_t qinit = ERTS_THR_Q_INIT_DEFAULT;
     erts_tse_t *tse = erts_tse_fetch();
+    ERTS_DECLARE_DUMMY(Uint no);
+
 #ifdef ERTS_SMP
     ErtsThrPrgrCallbacks callbacks;
 
@@ -483,10 +491,12 @@ static erts_tse_t *async_thread_init(ErtsAsyncQ *aq)
 
     /* Inform main thread that we are done initializing... */
     erts_mtx_lock(&async->init.data.mtx);
-    async->init.data.no_initialized++;
+    no = async->init.data.no_initialized++;
     erts_cnd_signal(&async->init.data.cnd);
     erts_mtx_unlock(&async->init.data.mtx);
 
+    erts_msacc_init_thread("async", no, 0);
+
     return tse;
 }
 
@@ -494,6 +504,7 @@ static void *async_main(void* arg)
 {
     ErtsAsyncQ *aq = (ErtsAsyncQ *) arg;
     erts_tse_t *tse = async_thread_init(aq);
+    ERTS_MSACC_DECLARE_CACHE();
 
     while (1) {
 	ErtsThrQPrepEnQ_t *prep_enq;
@@ -501,11 +512,14 @@ static void *async_main(void* arg)
 	if (is_nil(a->port))
 	    break; /* Time to die */
 
+        ERTS_MSACC_UPDATE_CACHE();
+
 #if ERTS_ASYNC_PRINT_JOB
 	erts_fprintf(stderr, "<- %ld\n", a->async_id);
 #endif
-
+        ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_PORT);
 	a->async_invoke(a->async_data);
+        ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_OTHER);
 
 	async_reply(a, prep_enq);
     }
@@ -628,10 +642,13 @@ long driver_async(ErlDrvPort ix, unsigned int* key,
     unsigned int qix;
 #if ERTS_USE_ASYNC_READY_Q
     Uint sched_id;
+    ERTS_MSACC_PUSH_STATE();
 
     sched_id = erts_get_scheduler_id();
     if (!sched_id)
 	sched_id = 1;
+#else
+    ERTS_MSACC_PUSH_STATE();
 #endif
 
     prt = erts_drvport2port(ix);
@@ -684,12 +701,17 @@ long driver_async(ErlDrvPort ix, unsigned int* key,
 	return id;
     }
 #endif
-
+    
+    ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_PORT);
     (*a->async_invoke)(a->async_data);
+    ERTS_MSACC_POP_STATE();
 
     if (async_ready(prt, a->async_data)) {
-	if (a->async_free != NULL)
+	if (a->async_free != NULL) {
+            ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_PORT);
 	    (*a->async_free)(a->async_data);
+            ERTS_MSACC_POP_STATE();
+        }
     }
     erts_free(ERTS_ALC_T_ASYNC, (void *) a);
 
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 06e7dc8661..017339e1f6 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -64,6 +64,7 @@ static Export* alloc_sizes_trap = NULL;
 static Export* gather_io_bytes_trap = NULL;
 
 static Export *gather_sched_wall_time_res_trap;
+static Export *gather_msacc_res_trap;
 static Export *gather_gc_info_res_trap;
 
 #define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1)
@@ -3260,6 +3261,14 @@ BIF_RETTYPE statistics_1(BIF_ALIST_1)
 	    szp = NULL;
 	    hpp = &hp;
 	}
+#ifdef ERTS_ENABLE_MSACC
+    } else if (BIF_ARG_1 == am_microstate_accounting) {
+        Eterm threads;
+        res = erts_msacc_request(BIF_P, ERTS_MSACC_GATHER, &threads);
+	if (is_non_value(res))
+	    BIF_RET(am_undefined);
+	BIF_TRAP2(gather_msacc_res_trap, BIF_P, res, threads);
+#endif
     } else if (BIF_ARG_1 == am_context_switches) {
 	Eterm cs = erts_make_integer(erts_get_total_context_switches(), BIF_P);
 	hp = HAlloc(BIF_P, 3);
@@ -4396,6 +4405,9 @@ erts_bif_info_init(void)
 	= erts_export_put(am_erlang, am_gather_gc_info_result, 1);
     gather_io_bytes_trap
 	= erts_export_put(am_erts_internal, am_gather_io_bytes, 2);
+    gather_msacc_res_trap
+	= erts_export_put(am_erts_internal, am_gather_microstate_accounting_result, 2);
+
     process_info_init();
     os_info_init();
 }
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 06acece471..21b03ae8bd 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -576,6 +576,7 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
     int reds;
     ErtsMonotonicTime start_time = 0; /* Shut up faulty warning... */
     ErtsSchedulerData *esdp;
+    ERTS_MSACC_PUSH_STATE_M();
 #ifdef USE_VM_PROBES
     DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE);
 #endif
@@ -588,6 +589,8 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
     else if (p->live_hf_end != ERTS_INVALID_HFRAG_PTR)
 	live_hf_end = p->live_hf_end;
 
+    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_GC);
+
     esdp = erts_get_scheduler_data();
 
     if (IS_TRACED_FL(p, F_TRACE_GC)) {
@@ -624,9 +627,11 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
     }
     else {
     do_major_collection:
+        ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_GC_FULL);
 	DTRACE2(gc_major_start, pidbuf, need);
 	reds = major_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now);
 	DTRACE2(gc_major_end, pidbuf, reclaimed_now);
+        ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_GC);
     }
 
     reset_active_writer(p);
@@ -669,6 +674,8 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
     FLAGS(p) &= ~F_FORCE_GC;
     p->live_hf_end = ERTS_INVALID_HFRAG_PTR;
 
+    ERTS_MSACC_POP_STATE_M();
+
 #ifdef CHECK_FOR_HOLES
     /*
      * We intentionally do not rescan the areas copied by the GC.
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 42aca726bf..520b504fcb 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -394,6 +394,7 @@ erl_init(int ncpu,
 #endif
     packet_parser_init();
     erl_nif_init();
+    erts_msacc_init();
 }
 
 static Eterm
@@ -1193,6 +1194,7 @@ early_init(int *argc, char **argv) /*
 	erts_thr_late_init(&elid);
     }
 #endif
+    erts_msacc_early_init();
 
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_late_init();
@@ -2220,6 +2222,7 @@ erl_start(int argc, char **argv)
 #else
     {
 	ErtsSchedulerData *esdp = erts_get_scheduler_data();
+        erts_msacc_init_thread("scheduler", 1, 1);
 	erts_thr_set_main_status(1, 1);
 #if ERTS_USE_ASYNC_READY_Q
 	esdp->aux_work_data.async_ready.queue
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index f7b4bd8041..598bf84c0b 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -137,6 +137,8 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"mmap_init_atoms",			NULL			},
     {	"drv_tsd",				NULL			},
     {	"async_enq_mtx",			NULL			},
+    {   "msacc_list_mutex",                     NULL                    },
+    {   "msacc_unmanaged_mutex",                NULL                    },
 #ifdef ERTS_SMP
     {	"atom_tab",				NULL			},
     {	"misc_op_list_pre_alloc_lock",		"address"		},
diff --git a/erts/emulator/beam/erl_msacc.c b/erts/emulator/beam/erl_msacc.c
new file mode 100644
index 0000000000..71e3fd8b6e
--- /dev/null
+++ b/erts/emulator/beam/erl_msacc.c
@@ -0,0 +1,486 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014-2015. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/*
+ * Description: Microstate accounting.
+ *
+ *              We keep track of the different states that the
+ *              Erlang VM threads are in, in order to provide
+ *              performance/debugging statistics. There is a
+ *              small overhead in enabling this, but in the big
+ *              scheme of things it should be negligible.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#define ERTS_MSACC_STATE_STRINGS 1
+
+#include "sys.h"
+#include "global.h"
+#include "erl_threads.h"
+#include "erl_bif_unique.h"
+#include "erl_map.h"
+#include "erl_msacc.h"
+
+#if ERTS_ENABLE_MSACC
+
+static Eterm erts_msacc_gather_stats(ErtsMsAcc *msacc, Eterm **hpp, Uint *szp);
+static void erts_msacc_reset(ErtsMsAcc *msacc);
+static ErtsMsAcc* get_msacc(void);
+
+#ifdef USE_THREADS
+erts_tsd_key_t ERTS_WRITE_UNLIKELY(erts_msacc_key);
+#else
+ErtsMsAcc *ERTS_WRITE_UNLIKELY(erts_msacc) = NULL;
+#endif
+int ERTS_WRITE_UNLIKELY(erts_msacc_enabled);
+
+static Eterm *erts_msacc_state_atoms = NULL;
+static erts_rwmtx_t msacc_mutex;
+static ErtsMsAcc *msacc_managed = NULL;
+#ifdef USE_THREADS
+static ErtsMsAcc *msacc_unmanaged = NULL;
+static Uint msacc_unmanaged_count = 0;
+#endif
+
+/* we have to split initiation as atoms are not inited in early init */
+void erts_msacc_early_init(void) {
+#ifndef ERTS_MSACC_ALWAYS_ON
+    erts_msacc_enabled = 0;
+#endif
+    erts_rwmtx_init(&msacc_mutex,"msacc_list_mutex");
+#ifdef USE_THREADS
+    erts_tsd_key_create(&erts_msacc_key,"erts_msacc_key");
+#else
+    erts_msacc = NULL;
+#endif
+}
+
+void erts_msacc_init(void) {
+    int i;
+    erts_msacc_state_atoms = erts_alloc(ERTS_ALC_T_MSACC,
+                                        sizeof(Eterm)*ERTS_MSACC_STATE_COUNT);
+    for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+        erts_msacc_state_atoms[i] = am_atom_put(erts_msacc_states[i],
+                                                strlen(erts_msacc_states[i]));
+    }
+}
+
+void erts_msacc_init_thread(char *type, int id, int managed) {
+    ErtsMsAcc *msacc;
+
+    msacc = erts_alloc(ERTS_ALC_T_MSACC, sizeof(ErtsMsAcc));
+
+    msacc->type = strdup(type);
+    msacc->id = make_small(id);
+    msacc->unmanaged = !managed;
+    msacc->tid = erts_thr_self();
+    msacc->perf_counter = 0;
+
+#ifdef USE_THREADS
+    erts_rwmtx_rwlock(&msacc_mutex);
+    if (!managed) {
+        erts_mtx_init(&msacc->mtx,"msacc_unmanaged_mutex");
+        msacc->next = msacc_unmanaged;
+        msacc_unmanaged = msacc;
+        msacc_unmanaged_count++;
+        ERTS_MSACC_TSD_SET(msacc);
+    } else {
+        msacc->next = msacc_managed;
+        msacc_managed = msacc;
+    }
+    erts_rwmtx_rwunlock(&msacc_mutex);
+#else
+    msacc_managed = msacc;
+#endif
+
+    erts_msacc_reset(msacc);
+
+#ifdef ERTS_MSACC_ALWAYS_ON
+    ERTS_MSACC_TSD_SET(msacc);
+    msacc->perf_counter = erts_sys_perf_counter();
+    msacc->state = ERTS_MSACC_STATE_OTHER;
+#endif
+}
+
+/*
+ * Creates a structure looking like this
+ * #{ type => scheduler, id => 1, counters => #{ State1 => Counter1 ... StateN => CounterN}}
+ */
+static
+Eterm erts_msacc_gather_stats(ErtsMsAcc *msacc, Eterm **hpp, Uint *szp) {
+    int i;
+    Eterm *hp;
+    Eterm key, state_key, state_map;
+    Eterm res = THE_NON_VALUE;
+    flatmap_t *map;
+
+    if (szp) {
+      *szp += MAP_HEADER_FLATMAP_SZ + 1 + 2*(3);
+      *szp += MAP_HEADER_FLATMAP_SZ + 1 + 2*(ERTS_MSACC_STATE_COUNT);
+      for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+          (void)erts_bld_sint64(NULL,szp,(Sint64)msacc->perf_counters[i]);
+#ifdef ERTS_MSACC_STATE_COUNTERS
+          (void)erts_bld_uint64(NULL,szp,msacc->state_counters[i]);
+          *szp += 3; /* tuple to put state+perf counter in */
+#endif
+      }
+    }
+
+    if (hpp) {
+        Eterm counters[ERTS_MSACC_STATE_COUNT];
+        hp = *hpp;
+        for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+            Eterm counter = erts_bld_sint64(&hp,NULL,(Sint64)msacc->perf_counters[i]);
+#ifdef ERTS_MSACC_STATE_COUNTERS
+            Eterm counter__ = erts_bld_uint64(&hp,NULL,msacc->state_counters[i]);
+            counters[i] = TUPLE2(hp,counter,counter__);
+            hp += 3;
+#else
+            counters[i] = counter;
+#endif
+        }
+
+      key = TUPLE3(hp,am_counters,am_id,am_type);
+      hp += 4;
+
+      state_key = make_tuple(hp);
+      hp[0] = make_arityval(ERTS_MSACC_STATE_COUNT);
+      
+      for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++)
+        hp[1+i] = erts_msacc_state_atoms[i];
+      hp += 1 + ERTS_MSACC_STATE_COUNT;
+
+      map = (flatmap_t*)hp;
+      hp += MAP_HEADER_FLATMAP_SZ;
+      map->thing_word = MAP_HEADER_FLATMAP;
+      map->size = ERTS_MSACC_STATE_COUNT;
+      map->keys = state_key;
+      for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++)
+            hp[i] = counters[i];
+      hp += ERTS_MSACC_STATE_COUNT;
+      state_map = make_flatmap(map);
+
+      map = (flatmap_t*)hp;
+      hp += MAP_HEADER_FLATMAP_SZ;
+      map->thing_word = MAP_HEADER_FLATMAP;
+      map->size = 3;
+      map->keys = key;
+      hp[0] = state_map;
+      hp[1] = msacc->id;
+      hp[2] = am_atom_put(msacc->type,strlen(msacc->type));
+      hp += 3;
+
+      *hpp = hp;
+      res = make_flatmap(map);
+    }
+
+    return res;
+}
+
+typedef struct {
+    int action;
+    Process *proc;
+    Eterm ref;
+    Eterm ref_heap[REF_THING_SIZE];
+    Uint req_sched;
+    erts_smp_atomic32_t refc;
+} ErtsMSAccReq;
+
+static ErtsMsAcc* get_msacc(void) {
+    ErtsMsAcc *msacc;
+    erts_rwmtx_rlock(&msacc_mutex);
+    msacc = msacc_managed;
+    while (!erts_equal_tids(msacc->tid,erts_thr_self())) {
+        msacc = msacc->next;
+        ASSERT(msacc != NULL);
+    }
+    erts_rwmtx_runlock(&msacc_mutex);
+    return msacc;
+}
+
+static void send_reply(ErtsMsAcc *msacc, ErtsMSAccReq *msaccrp) {
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    Process *rp = msaccrp->proc;
+    ErtsMessage *msgp = NULL;
+    Eterm **hpp, *hp;
+    Eterm ref_copy = NIL, msg;
+    Uint sz, *szp;
+    ErlOffHeap *ohp = NULL;
+    ErtsProcLocks rp_locks = (esdp && msaccrp->req_sched == esdp->no
+                              ? ERTS_PROC_LOCK_MAIN : 0);
+
+    sz = 0;
+    hpp = NULL;
+    szp = &sz;
+
+    if (msacc->unmanaged) erts_mtx_lock(&msacc->mtx);
+
+    while (1) {
+	if (hpp)
+            ref_copy = STORE_NC(hpp, ohp, msaccrp->ref);
+	else
+            *szp += REF_THING_SIZE;
+
+	if (msaccrp->action != ERTS_MSACC_GATHER)
+            msg = ref_copy;
+	else {
+            msg = erts_msacc_gather_stats(msacc, hpp, szp);
+            msg = erts_bld_tuple(hpp, szp, 2, ref_copy, msg);
+	}
+	if (hpp)
+            break;
+
+	msgp = erts_alloc_message_heap(rp, &rp_locks, sz, &hp, &ohp);
+        hpp = &hp;
+	szp = NULL;
+    }
+
+    if (msacc->unmanaged) erts_mtx_unlock(&msacc->mtx);
+
+    erts_queue_message(rp, &rp_locks, msgp, msg, NIL);
+
+    if (esdp && msaccrp->req_sched == esdp->no)
+	rp_locks &= ~ERTS_PROC_LOCK_MAIN;
+
+    if (rp_locks)
+	erts_smp_proc_unlock(rp, rp_locks);
+
+}
+
+static void
+reply_msacc(void *vmsaccrp)
+{
+    ErtsMsAcc *msacc = ERTS_MSACC_TSD_GET();
+    ErtsMSAccReq *msaccrp = (ErtsMSAccReq *) vmsaccrp;
+
+    ASSERT(!msacc || !msacc->unmanaged);
+
+    if (msaccrp->action == ERTS_MSACC_ENABLE && !msacc) {
+        msacc = get_msacc();
+
+        msacc->perf_counter = erts_sys_perf_counter();
+
+        msacc->state = ERTS_MSACC_STATE_OTHER;
+
+        ERTS_MSACC_TSD_SET(msacc);
+
+    } else if (msaccrp->action == ERTS_MSACC_DISABLE && msacc) {
+        ERTS_MSACC_TSD_SET(NULL);
+    } else if (msaccrp->action == ERTS_MSACC_RESET) {
+        msacc = msacc ? msacc : get_msacc();
+        erts_msacc_reset(msacc);
+    } else if (msaccrp->action == ERTS_MSACC_GATHER && !msacc) {
+        msacc = get_msacc();
+    }
+
+    ASSERT(!msacc || !msacc->unmanaged);
+
+    send_reply(msacc, msaccrp);
+
+    erts_proc_dec_refc(msaccrp->proc);
+
+    if (erts_smp_atomic32_dec_read_nob(&msaccrp->refc) == 0)
+      erts_free(ERTS_ALC_T_MSACC, vmsaccrp);
+}
+
+static void erts_msacc_reset(ErtsMsAcc *msacc) {
+  int i;
+  if (msacc->unmanaged) erts_mtx_lock(&msacc->mtx);
+
+  for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+      msacc->perf_counters[i] = 0;
+#ifdef ERTS_MSACC_STATE_COUNTERS
+      msacc->state_counters[i] = 0;
+#endif
+  }
+
+  if (msacc->unmanaged) erts_mtx_unlock(&msacc->mtx);
+}
+
+#endif /* ERTS_ENABLE_MSACC */
+
+
+/*
+ * This function is responsible for enabling, disabling, resetting and
+ * gathering data related to microstate accounting.
+ *
+ * Managed threads and unmanaged threads are handled differently.
+ *   - managed threads get a misc_aux job telling them to switch on msacc
+ *   - unmanaged have some fields protected by a mutex that has to be taken
+ *     before any values can be updated
+ *
+ * For performance reasons there is also a global value erts_msacc_enabled
+ * that controls the state of all threads. Statistics gathering is only on
+ * if erts_msacc_enabled && msacc is true.
+ */
+Eterm
+erts_msacc_request(Process *c_p, int action, Eterm *threads)
+{
+#ifdef ERTS_ENABLE_MSACC
+    ErtsMsAcc *msacc =  ERTS_MSACC_TSD_GET();
+    ErtsSchedulerData *esdp = ERTS_PROC_GET_SCHDATA(c_p);
+    Eterm ref;
+    ErtsMSAccReq *msaccrp;
+    Eterm *hp;
+
+
+#ifdef ERTS_MSACC_ALWAYS_ON
+    if (action == ERTS_MSACC_ENABLE || action == ERTS_MSACC_DISABLE)
+        return THE_NON_VALUE;
+#else
+    /* take care of double enable, and double disable here */
+    if (msacc && action == ERTS_MSACC_ENABLE) {
+        return THE_NON_VALUE;
+    } else if (!msacc && action == ERTS_MSACC_DISABLE) {
+        return THE_NON_VALUE;
+    }
+#endif
+
+    ref = erts_make_ref(c_p);
+
+    msaccrp = erts_alloc(ERTS_ALC_T_MSACC, sizeof(ErtsMSAccReq));
+    hp = &msaccrp->ref_heap[0];
+
+    msaccrp->action = action;
+    msaccrp->proc = c_p;
+    msaccrp->ref = STORE_NC(&hp, NULL, ref);
+    msaccrp->req_sched = esdp->no;
+
+#ifdef ERTS_SMP
+    *threads = erts_no_schedulers;
+    *threads += 1; /* aux thread */
+#else
+    *threads = 1;
+#endif
+
+    erts_smp_atomic32_init_nob(&msaccrp->refc,(erts_aint32_t)*threads);
+
+    erts_proc_add_refc(c_p, *threads);
+
+    if (erts_no_schedulers > 1)
+	erts_schedule_multi_misc_aux_work(1,
+                                          erts_no_schedulers,
+                                          reply_msacc,
+                                          (void *) msaccrp);
+#ifdef ERTS_SMP
+    /* aux thread */
+    erts_schedule_misc_aux_work(0, reply_msacc, (void *) msaccrp);
+#endif
+
+#ifdef USE_THREADS
+    /* Manage unmanaged threads */
+    switch (action) {
+    case ERTS_MSACC_GATHER: {
+        Uint unmanaged_count;
+        ErtsMsAcc *msacc, **unmanaged;
+        int i = 0;
+
+        /* we copy a list of pointers here so that we do not have to have
+           the msacc_mutex when sending messages */
+        erts_rwmtx_rlock(&msacc_mutex);
+        unmanaged_count = msacc_unmanaged_count;
+        unmanaged = erts_alloc(ERTS_ALC_T_MSACC,
+                               sizeof(ErtsMsAcc*)*unmanaged_count);
+
+        for (i = 0, msacc = msacc_unmanaged;
+             i < unmanaged_count;
+             i++, msacc = msacc->next) {
+            unmanaged[i] = msacc;
+        }
+        erts_rwmtx_runlock(&msacc_mutex);
+
+        for (i = 0; i < unmanaged_count; i++) {
+            erts_mtx_lock(&unmanaged[i]->mtx);
+            if (unmanaged[i]->perf_counter) {
+                ErtsSysPerfCounter perf_counter;
+                /* if enabled update stats */
+                perf_counter = erts_sys_perf_counter();
+                unmanaged[i]->perf_counters[unmanaged[i]->state] +=
+                    perf_counter - unmanaged[i]->perf_counter;
+                unmanaged[i]->perf_counter = perf_counter;
+            }
+            erts_mtx_unlock(&unmanaged[i]->mtx);
+            send_reply(unmanaged[i],msaccrp);
+        }
+        erts_free(ERTS_ALC_T_MSACC,unmanaged);
+        /* We have just sent unmanaged_count messages, so bump no of threads */
+        *threads += unmanaged_count;
+        break;
+    }
+    case ERTS_MSACC_RESET: {
+        ErtsMsAcc *msacc;
+        erts_rwmtx_rlock(&msacc_mutex);
+        for (msacc = msacc_unmanaged; msacc != NULL; msacc = msacc->next)
+            erts_msacc_reset(msacc);
+        erts_rwmtx_runlock(&msacc_mutex);
+        break;
+    }
+    case ERTS_MSACC_ENABLE: {
+        erts_rwmtx_rlock(&msacc_mutex);
+        for (msacc = msacc_unmanaged; msacc != NULL; msacc = msacc->next) {
+            erts_mtx_lock(&msacc->mtx);
+            msacc->perf_counter = erts_sys_perf_counter();
+            /* we assume the unmanaged thread is sleeping */
+            msacc->state = ERTS_MSACC_STATE_SLEEP;
+            erts_mtx_unlock(&msacc->mtx);
+        }
+        erts_rwmtx_runlock(&msacc_mutex);
+        break;
+    }
+    case ERTS_MSACC_DISABLE: {
+        ErtsSysPerfCounter perf_counter;
+        erts_rwmtx_rlock(&msacc_mutex);
+        /* make sure to update stats with latest results */
+        for (msacc = msacc_unmanaged; msacc != NULL; msacc = msacc->next) {
+            erts_mtx_lock(&msacc->mtx);
+            perf_counter = erts_sys_perf_counter();
+            msacc->perf_counters[msacc->state] += perf_counter - msacc->perf_counter;
+            msacc->perf_counter = 0;
+            erts_mtx_unlock(&msacc->mtx);
+        }
+        erts_rwmtx_runlock(&msacc_mutex);
+        break;
+    }
+    default: { ASSERT(0); }
+    }
+
+#endif
+
+    *threads = make_small(*threads);
+
+    reply_msacc((void *) msaccrp);
+
+#ifndef ERTS_MSACC_ALWAYS_ON
+    /* enable/disable the global value */
+    if (action == ERTS_MSACC_ENABLE) {
+        erts_msacc_enabled = 1;
+    } else if (action == ERTS_MSACC_DISABLE) {
+        erts_msacc_enabled = 0;
+    }
+#endif
+
+    return ref;
+#else
+    return THE_NON_VALUE;
+#endif
+}
diff --git a/erts/emulator/beam/erl_msacc.h b/erts/emulator/beam/erl_msacc.h
new file mode 100644
index 0000000000..284388f7aa
--- /dev/null
+++ b/erts/emulator/beam/erl_msacc.h
@@ -0,0 +1,409 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014-2015. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERL_MSACC_H__
+#define ERL_MSACC_H__
+
+/* Can be enabled/disabled via configure */
+#if ERTS_ENABLE_MSACC == 2
+#define ERTS_MSACC_EXTENDED_STATES 1
+#endif
+
+/* Uncomment this to also count the number of
+   transitions to a state. This will add a count
+   to the counter map. */
+/* #define ERTS_MSACC_STATE_COUNTERS 1 */
+
+/* Uncomment this to make msacc to always be on,
+   this reduces overhead a little bit when profiling */
+/* #define ERTS_MSACC_ALWAYS_ON 1 */
+
+#define ERTS_MSACC_DISABLE 0
+#define ERTS_MSACC_ENABLE  1
+#define ERTS_MSACC_RESET   2
+#define ERTS_MSACC_GATHER  3
+
+/*
+ * When adding a new state, you have to:
+ * * Add it here
+ * * Increment ERTS_MSACC_STATE_COUNT
+ * * Add string value to erts_msacc_states
+ * * Have to be in alphabetical order!
+ * * Only add states to the non-extended section after
+ *   careful benchmarking to make sure the overhead
+ *   when disabled is minimal.
+ */
+
+#ifndef ERTS_MSACC_EXTENDED_STATES
+#define ERTS_MSACC_STATE_AUX       0
+#define ERTS_MSACC_STATE_CHECK_IO  1
+#define ERTS_MSACC_STATE_EMULATOR  2
+#define ERTS_MSACC_STATE_GC        3
+#define ERTS_MSACC_STATE_OTHER     4
+#define ERTS_MSACC_STATE_PORT      5
+#define ERTS_MSACC_STATE_SLEEP     6
+
+#define ERTS_MSACC_STATE_COUNT 7
+
+#if ERTS_MSACC_STATE_STRINGS && ERTS_ENABLE_MSACC
+static char *erts_msacc_states[] = {
+    "aux",
+    "check_io",
+    "emulator",
+    "gc",
+    "other",
+    "port",
+    "sleep"
+};
+#endif
+
+#else
+
+#define ERTS_MSACC_STATE_ALLOC     0
+#define ERTS_MSACC_STATE_AUX       1
+#define ERTS_MSACC_STATE_BIF       2
+#define ERTS_MSACC_STATE_BUSY_WAIT 3
+#define ERTS_MSACC_STATE_CHECK_IO  4
+#define ERTS_MSACC_STATE_EMULATOR  5
+#define ERTS_MSACC_STATE_ETS       6
+#define ERTS_MSACC_STATE_GC        7
+#define ERTS_MSACC_STATE_GC_FULL   8
+#define ERTS_MSACC_STATE_NIF       9
+#define ERTS_MSACC_STATE_OTHER     10
+#define ERTS_MSACC_STATE_PORT      11
+#define ERTS_MSACC_STATE_SEND      12
+#define ERTS_MSACC_STATE_SLEEP     13
+#define ERTS_MSACC_STATE_TIMERS    14
+
+#define ERTS_MSACC_STATE_COUNT 15
+
+#if ERTS_MSACC_STATE_STRINGS
+static char *erts_msacc_states[] = {
+    "alloc",
+    "aux",
+    "bif",
+    "busy_wait",
+    "check_io",
+    "emulator",
+    "ets",
+    "gc",
+    "gc_full",
+    "nif",
+    "other",
+    "port",
+    "send",
+    "sleep",
+    "timers"
+};
+#endif
+
+#endif
+
+typedef struct erl_msacc_t_ ErtsMsAcc;
+
+struct erl_msacc_t_ {
+
+    /* the the values below are protected by mtx iff unmanaged = 1 */
+    ErtsSysPerfCounter perf_counter;
+    ErtsSysPerfCounter perf_counters[ERTS_MSACC_STATE_COUNT];
+#ifdef ERTS_MSACC_STATE_COUNTERS
+    Uint64 state_counters[ERTS_MSACC_STATE_COUNT];
+#endif
+    Uint state;
+
+    /* protected by msacc_mutex in erl_msacc.c, and should be constant */
+    int unmanaged;
+    erts_mtx_t mtx;
+    ErtsMsAcc *next;
+    erts_tid_t tid;
+    Eterm id;
+    char *type;
+};
+
+#if ERTS_ENABLE_MSACC
+
+#define ERTS_MSACC_INLINE ERTS_GLB_INLINE
+
+#ifdef USE_THREADS
+extern erts_tsd_key_t erts_msacc_key;
+#else
+extern ErtsMsAcc *erts_msacc;
+#endif
+
+#ifdef ERTS_MSACC_ALWAYS_ON
+#define erts_msacc_enabled 1
+#else
+extern int erts_msacc_enabled;
+#endif
+
+#ifdef USE_THREADS
+#define ERTS_MSACC_TSD_GET() erts_tsd_get(erts_msacc_key)
+#define ERTS_MSACC_TSD_SET(tsd) erts_tsd_set(erts_msacc_key,tsd)
+#else
+#define ERTS_MSACC_TSD_GET() erts_msacc
+#define ERTS_MSACC_TSD_SET(tsd) erts_msacc = tsd
+#endif
+
+void erts_msacc_early_init(void);
+void erts_msacc_init(void);
+void erts_msacc_init_thread(char *type, int id, int liberty);
+
+/* The defines below are used to instrument the vm code
+ * with different state changes. There are two variants
+ * of each define. One that has a cached ErtsMsAcc *
+ * that it can use, and one that does not.
+ * The cached values are necessary to have in order to get
+ * low enough overhead when running without msacc enabled.
+ *
+ * The two most common patterns to use the function with are:
+ *
+ *   ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_NEWSTATE);
+ *     ... call other function in new state ...
+ *   ERTS_MSACC_POP_STATE();
+ *
+ * Note that the erts_msacc_push* function declare new variables, so
+ * to conform with C89 we have to call it in the beginning of a function.
+ * We might not want to change state it the beginning though, so we use this:
+ *
+ *   ERTS_MSACC_PUSH_STATE();
+ *     ... some other code ...
+ *   ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_NEWSTATE);
+ *     ... call other function in new state ...
+ *   ERTS_MSACC_POP_STATE();
+ *
+ * Notice that we used the cached version of set_state as push_state already
+ * read the erts_msacc_enabled to the cache.
+ *
+ * Most macros also have other variants with the suffix _m which means that
+ * they are known to only be called in managed threads, or with the _x suffix
+ * which means that it should only be used in an emulator compiled with
+ * extended states.
+ *
+ * Here is a listing of the entire api:
+ *
+ *  void ERTS_MSACC_DECLARE_CACHE()
+ *  void ERTS_MSACC_UPDATE_CACHE()
+ *  void ERTS_MSACC_IS_ENABLED()
+ *  void ERTS_MSACC_IS_ENABLED_CACHED()
+ *
+ *  void ERTS_MSACC_PUSH_STATE()
+ *  void ERTS_MSACC_SET_STATE(int state)
+ *  void ERTS_MSACC_PUSH_AND_SET_STATE(int state)
+ *
+ *  void ERTS_MSACC_PUSH_STATE_CACHED()
+ *  void ERTS_MSACC_SET_STATE_CACHED(int state)
+ *  void ERTS_MSACC_PUSH_AND_SET_STATE_CACHED(int state)
+ *  void ERTS_MSACC_POP_STATE()
+ *
+ *  void ERTS_MSACC_PUSH_STATE_M()
+ *  void ERTS_MSACC_PUSH_STATE_CACHED_M()
+ *  void ERTS_MSACC_SET_STATE_CACHED_M(int state)
+ *  void ERTS_MSACC_SET_STATE_M(int state)
+ *  void ERTS_MSACC_POP_STATE_M()
+ *  void ERTS_MSACC_PUSH_AND_SET_STATE_M(int state)
+ *
+ *  Most functions are also available with an _x suffix that are only enabled
+ *  when using the extra states. If they are not, just add them to the end
+ *  of this file.
+ */
+
+/* cache handling functions */
+#define ERTS_MSACC_IS_ENABLED() ERTS_UNLIKELY(erts_msacc_enabled)
+#define ERTS_MSACC_DECLARE_CACHE()                                      \
+    ErtsMsAcc *ERTS_MSACC_UPDATE_CACHE();                                 \
+    ERTS_DECLARE_DUMMY(Uint __erts_msacc_state) = ERTS_MSACC_STATE_OTHER;
+#define ERTS_MSACC_IS_ENABLED_CACHED() ERTS_UNLIKELY(__erts_msacc_cache != NULL)
+#define ERTS_MSACC_UPDATE_CACHE()                                       \
+    __erts_msacc_cache = erts_msacc_enabled ? ERTS_MSACC_TSD_GET() : NULL
+
+
+/* The defines below implicitly declare and load a new cache */
+#define ERTS_MSACC_PUSH_STATE()                           \
+    ERTS_MSACC_DECLARE_CACHE();                           \
+    ERTS_MSACC_PUSH_STATE_CACHED()
+#define ERTS_MSACC_SET_STATE(state)                                     \
+    ERTS_MSACC_DECLARE_CACHE();                                         \
+    ERTS_MSACC_SET_STATE_CACHED(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE(state)                    \
+    ERTS_MSACC_PUSH_STATE(); ERTS_MSACC_SET_STATE_CACHED(state)
+
+/* The defines below need an already declared cache to work */
+#define ERTS_MSACC_PUSH_STATE_CACHED()                                  \
+    __erts_msacc_state = ERTS_MSACC_IS_ENABLED_CACHED() ?               \
+        erts_msacc_get_state_um__(__erts_msacc_cache) : ERTS_MSACC_STATE_OTHER
+#define ERTS_MSACC_SET_STATE_CACHED(state) \
+    if (ERTS_MSACC_IS_ENABLED_CACHED())                         \
+        erts_msacc_set_state_um__(__erts_msacc_cache, state, 1)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_CACHED(state) \
+    ERTS_MSACC_PUSH_STATE_CACHED(); ERTS_MSACC_SET_STATE_CACHED(state)
+#define ERTS_MSACC_POP_STATE()                                          \
+    if (ERTS_MSACC_IS_ENABLED_CACHED())                                 \
+        erts_msacc_set_state_um__(__erts_msacc_cache, __erts_msacc_state, 0)
+
+/* Only use these defines when we know that we have in a managed thread */
+#define ERTS_MSACC_PUSH_STATE_M()                         \
+    ERTS_MSACC_DECLARE_CACHE();                           \
+    ERTS_MSACC_PUSH_STATE_CACHED_M()
+#define ERTS_MSACC_PUSH_STATE_CACHED_M()                                \
+    __erts_msacc_state = ERTS_MSACC_IS_ENABLED_CACHED() ?    \
+        erts_msacc_get_state_m__(__erts_msacc_cache) : ERTS_MSACC_STATE_OTHER
+#define ERTS_MSACC_SET_STATE_M(state)                   \
+    ERTS_MSACC_DECLARE_CACHE();                         \
+    ERTS_MSACC_SET_STATE_CACHED_M(state)
+#define ERTS_MSACC_SET_STATE_CACHED_M(state)            \
+    if (ERTS_MSACC_IS_ENABLED_CACHED())      \
+        erts_msacc_set_state_m__(__erts_msacc_cache, state, 1)
+#define ERTS_MSACC_POP_STATE_M()                                  \
+    if (ERTS_MSACC_IS_ENABLED_CACHED())                      \
+        erts_msacc_set_state_m__(__erts_msacc_cache, __erts_msacc_state, 0)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_M(state)                    \
+    ERTS_MSACC_PUSH_STATE_M(); ERTS_MSACC_SET_STATE_CACHED_M(state)
+
+ERTS_MSACC_INLINE
+void erts_msacc_set_state_um__(ErtsMsAcc *msacc,Uint state,int increment);
+ERTS_MSACC_INLINE
+void erts_msacc_set_state_m__(ErtsMsAcc *msacc,Uint state,int increment);
+
+ERTS_MSACC_INLINE
+Uint erts_msacc_get_state_um__(ErtsMsAcc *msacc);
+ERTS_MSACC_INLINE
+Uint erts_msacc_get_state_m__(ErtsMsAcc *msacc);
+
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_MSACC_INLINE
+Uint erts_msacc_get_state_um__(ErtsMsAcc *msacc) {
+    Uint state;
+    if (msacc->unmanaged)
+        erts_mtx_lock(&msacc->mtx);
+    state = msacc->state;
+    if (msacc->unmanaged)
+        erts_mtx_unlock(&msacc->mtx);
+    return state;
+}
+
+ERTS_MSACC_INLINE
+Uint erts_msacc_get_state_m__(ErtsMsAcc *msacc) {
+    return msacc->state;
+}
+
+ERTS_MSACC_INLINE
+void erts_msacc_set_state_um__(ErtsMsAcc *msacc, Uint new_state, int increment) {
+    if (ERTS_UNLIKELY(msacc->unmanaged)) {
+        erts_mtx_lock(&msacc->mtx);
+        msacc->state = new_state;
+        if (ERTS_LIKELY(!msacc->perf_counter)) {
+            erts_mtx_unlock(&msacc->mtx);
+            return;
+        }
+    }
+
+    erts_msacc_set_state_m__(msacc,new_state,increment);
+
+    if (ERTS_UNLIKELY(msacc->unmanaged))
+        erts_mtx_unlock(&msacc->mtx);
+}
+
+ERTS_MSACC_INLINE
+void erts_msacc_set_state_m__(ErtsMsAcc *msacc, Uint new_state, int increment) {
+    ErtsSysPerfCounter prev_perf_counter;
+    Sint64 diff;
+
+    if (new_state == msacc->state)
+        return;
+
+    prev_perf_counter = msacc->perf_counter;
+    msacc->perf_counter = erts_sys_perf_counter();
+    diff = msacc->perf_counter - prev_perf_counter;
+    ASSERT(diff >= 0);
+    msacc->perf_counters[msacc->state] += diff;
+#ifdef ERTS_MSACC_STATE_COUNTERS
+    msacc->state_counters[new_state] += increment;
+#endif
+    msacc->state = new_state;
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#else
+
+#define ERTS_MSACC_IS_ENABLED() 0
+#define erts_msacc_early_init()
+#define erts_msacc_init()
+#define erts_msacc_init_thread(type, id, liberty)
+#define ERTS_MSACC_PUSH_STATE()
+#define ERTS_MSACC_PUSH_STATE_CACHED()
+#define ERTS_MSACC_POP_STATE()
+#define ERTS_MSACC_SET_STATE(state)
+#define ERTS_MSACC_SET_STATE_CACHED(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_CACHED(state)
+#define ERTS_MSACC_UPDATE_CACHE()
+#define ERTS_MSACC_IS_ENABLED_CACHED()
+#define ERTS_MSACC_DECLARE_CACHE()
+#define ERTS_MSACC_PUSH_STATE_M()
+#define ERTS_MSACC_PUSH_STATE_CACHED_M()
+#define ERTS_MSACC_SET_STATE_CACHED_M(state)
+#define ERTS_MSACC_POP_STATE_M()
+#define ERTS_MSACC_PUSH_AND_SET_STATE_M(state)
+
+
+#endif /* ERTS_ENABLE_MSACC */
+
+#ifndef ERTS_MSACC_EXTENDED_STATES
+
+#define ERTS_MSACC_PUSH_STATE_X()
+#define ERTS_MSACC_POP_STATE_X()
+#define ERTS_MSACC_SET_STATE_X(state)
+#define ERTS_MSACC_SET_STATE_M_X(state)
+#define ERTS_MSACC_SET_STATE_CACHED_X(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_X(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_CACHED_X(state)
+#define ERTS_MSACC_UPDATE_CACHE_X()
+#define ERTS_MSACC_IS_ENABLED_CACHED_X() 0
+#define ERTS_MSACC_DECLARE_CACHE_X()
+#define ERTS_MSACC_PUSH_STATE_M_X()
+#define ERTS_MSACC_PUSH_STATE_CACHED_M_X()
+#define ERTS_MSACC_SET_STATE_CACHED_M_X(state)
+#define ERTS_MSACC_POP_STATE_M_X()
+#define ERTS_MSACC_PUSH_AND_SET_STATE_M_X(state)
+
+#else
+
+#define ERTS_MSACC_PUSH_STATE_X() ERTS_MSACC_PUSH_STATE()
+#define ERTS_MSACC_POP_STATE_X() ERTS_MSACC_POP_STATE()
+#define ERTS_MSACC_SET_STATE_X(state) ERTS_MSACC_SET_STATE(state)
+#define ERTS_MSACC_SET_STATE_M_X(state) ERTS_MSACC_SET_STATE_M(state)
+#define ERTS_MSACC_SET_STATE_CACHED_X(state) ERTS_MSACC_SET_STATE_CACHED(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_X(state) ERTS_MSACC_PUSH_AND_SET_STATE(state)
+#define ERTS_MSACC_PUSH_AND_SET_STATE_CACHED_X(state) ERTS_MSACC_PUSH_AND_SET_STATE_CACHED(state)
+#define ERTS_MSACC_UPDATE_CACHE_X() ERTS_MSACC_UPDATE_CACHE()
+#define ERTS_MSACC_IS_ENABLED_CACHED_X() ERTS_MSACC_IS_ENABLED_CACHED()
+#define ERTS_MSACC_DECLARE_CACHE_X() ERTS_MSACC_DECLARE_CACHE()
+#define ERTS_MSACC_PUSH_STATE_M_X() ERTS_MSACC_PUSH_STATE_M()
+#define ERTS_MSACC_PUSH_STATE_CACHED_M_X() ERTS_MSACC_PUSH_STATE_CACHED_M()
+#define ERTS_MSACC_SET_STATE_CACHED_M_X(state) ERTS_MSACC_SET_STATE_CACHED_M(state)
+#define ERTS_MSACC_POP_STATE_M_X() ERTS_MSACC_POP_STATE_M()
+#define ERTS_MSACC_PUSH_AND_SET_STATE_M_X(state) ERTS_MSACC_PUSH_AND_SET_STATE_M(state)
+
+#endif /* !ERTS_MSACC_EXTENDED_STATES */
+
+#endif /* ERL_MSACC_H__ */
diff --git a/erts/emulator/beam/erl_port_task.c b/erts/emulator/beam/erl_port_task.c
index 2c09834d19..197b328fe2 100644
--- a/erts/emulator/beam/erl_port_task.c
+++ b/erts/emulator/beam/erl_port_task.c
@@ -1648,6 +1648,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
     int active;
     Uint64 start_time = 0;
     ErtsSchedulerData *esdp = runq->scheduler;
+    ERTS_MSACC_PUSH_STATE_M();
 
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(runq));
 
@@ -1690,6 +1691,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 
     state = erts_atomic32_read_nob(&pp->state);
     pp->reds = ERTS_PORT_REDS_EXECUTE;
+    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
     goto begin_handle_tasks;
 
     while (1) {
@@ -1822,6 +1824,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
     }
 
     erts_unblock_fpe(fpe_was_unmasked);
+    ERTS_MSACC_POP_STATE_M();
 
 
     if (io_tasks_executed) {
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 7d194f9840..8e1ebe795c 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -148,14 +148,14 @@ extern BeamInstr beam_apply[];
 extern BeamInstr beam_exit[];
 extern BeamInstr beam_continue_exit[];
 
-int erts_default_spo_flags = 0;
-int erts_eager_check_io = 1;
-int erts_sched_compact_load;
-int erts_sched_balance_util = 0;
-Uint erts_no_schedulers;
+int ERTS_WRITE_UNLIKELY(erts_default_spo_flags) = 0;
+int ERTS_WRITE_UNLIKELY(erts_eager_check_io) = 1;
+int ERTS_WRITE_UNLIKELY(erts_sched_compact_load);
+int ERTS_WRITE_UNLIKELY(erts_sched_balance_util) = 0;
+Uint ERTS_WRITE_UNLIKELY(erts_no_schedulers);
 #ifdef ERTS_DIRTY_SCHEDULERS
-Uint erts_no_dirty_cpu_schedulers;
-Uint erts_no_dirty_io_schedulers;
+Uint ERTS_WRITE_UNLIKELY(erts_no_dirty_cpu_schedulers);
+Uint ERTS_WRITE_UNLIKELY(erts_no_dirty_io_schedulers);
 #endif
 
 static char *erts_aux_work_flag_descr[ERTS_SSI_AUX_WORK_NO_FLAGS] = {0};
@@ -295,7 +295,7 @@ do {							\
 erts_sched_stat_t erts_sched_stat;
 
 #ifdef USE_THREADS
-static erts_tsd_key_t sched_data_key;
+static erts_tsd_key_t ERTS_WRITE_UNLIKELY(sched_data_key);
 #endif
 
 static erts_smp_atomic32_t function_calls;
@@ -335,10 +335,10 @@ static ErtsAlignedSchedulerSleepInfo *aligned_dirty_io_sched_sleep_info;
 
 static Uint last_reductions;
 static Uint last_exact_reductions;
-Eterm erts_system_monitor;
-Eterm erts_system_monitor_long_gc;
-Uint erts_system_monitor_long_schedule;
-Eterm erts_system_monitor_large_heap;
+Eterm ERTS_WRITE_UNLIKELY(erts_system_monitor);
+Eterm ERTS_WRITE_UNLIKELY(erts_system_monitor_long_gc);
+Uint ERTS_WRITE_UNLIKELY(erts_system_monitor_long_schedule);
+Eterm ERTS_WRITE_UNLIKELY(erts_system_monitor_large_heap);
 struct erts_system_monitor_flags_t erts_system_monitor_flags;
 
 /* system performance monitor */
@@ -941,6 +941,12 @@ sched_wall_time_change(ErtsSchedulerData *esdp, int working)
 	    }
 	}
     }
+    if (!working) {
+        ERTS_MSACC_SET_STATE_M_X(ERTS_MSACC_STATE_BUSY_WAIT);
+    } else {
+        ERTS_MSACC_SET_STATE_M_X(ERTS_MSACC_STATE_OTHER);
+    }
+
 }
 
 typedef struct {
@@ -1696,15 +1702,17 @@ handle_delayed_dealloc(ErtsAuxWorkData *awdp, erts_aint32_t aux_work, int waitin
     int need_thr_progress = 0;
     ErtsThrPrgrVal wakeup = ERTS_THR_PRGR_INVALID;
     int more_work = 0;
-
+    ERTS_MSACC_PUSH_STATE_M_X();
 #ifdef ERTS_DIRTY_SCHEDULERS
     ASSERT(!awdp->esdp || !ERTS_SCHEDULER_IS_DIRTY(awdp->esdp));
 #endif
     unset_aux_work_flags(ssi, ERTS_SSI_AUX_WORK_DD);
+    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_ALLOC);
     erts_alloc_scheduler_handle_delayed_dealloc((void *) awdp->esdp,
 						&need_thr_progress,
 						&wakeup,
 						&more_work);
+    ERTS_MSACC_POP_STATE_M_X();
     if (more_work) {
 	if (set_aux_work_flags(ssi, ERTS_SSI_AUX_WORK_DD)
 	    & ERTS_SSI_AUX_WORK_DD_THR_PRGR) {
@@ -2176,12 +2184,15 @@ handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work, int waiting)
 	ERTS_DBG_CHK_AUX_WORK_VAL(aux_work); \
 	if (!(aux_work & ~ignore)) { \
 	    ERTS_DBG_CHK_AUX_WORK_VAL(aux_work); \
+            ERTS_MSACC_UPDATE_CACHE();       \
+            ERTS_MSACC_POP_STATE_M();              \
 	    return aux_work; \
 	} \
     }
 
     erts_aint32_t aux_work = orig_aux_work;
     erts_aint32_t ignore = 0;
+    ERTS_MSACC_PUSH_AND_SET_STATE_M(ERTS_MSACC_STATE_AUX);
 
     ASSERT(!awdp->esdp || !ERTS_SCHEDULER_IS_DIRTY(awdp->esdp));
 #ifdef ERTS_SMP
@@ -2272,6 +2283,8 @@ handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work, int waiting)
 	haw_thr_prgr_current_check_progress(awdp);
 #endif
 
+    ERTS_MSACC_UPDATE_CACHE();
+    ERTS_MSACC_POP_STATE_M();
     return aux_work;
 
 #undef HANDLE_AUX_WORK
@@ -2779,6 +2792,8 @@ aux_thread(void *unused)
 
     ssi->event = erts_tse_fetch();
 
+    erts_msacc_init_thread("aux", 1, 1);
+
     callbacks.arg = (void *) ssi;
     callbacks.wakeup = thr_prgr_wakeup;
     callbacks.prepare_wait = thr_prgr_prep_wait;
@@ -2789,6 +2804,7 @@ aux_thread(void *unused)
     init_aux_work_data(awdp, NULL, NULL);
     awdp->ssi = ssi;
 
+
     sched_prep_spin_wait(ssi);
 
     while (1) {
@@ -2842,6 +2858,9 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 #ifdef ERTS_SMP
     int thr_prgr_active = 1;
     erts_aint32_t flgs;
+#endif
+    ERTS_MSACC_PUSH_STATE_M();
+#ifdef ERTS_SMP
 
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
 
@@ -2898,6 +2917,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 		    sched_wall_time_change(esdp, 1);
 		}
 		aux_work = handle_aux_work(&esdp->aux_work_data, aux_work, 1);
+                ERTS_MSACC_UPDATE_CACHE();
 		if (aux_work && erts_thr_progress_update(esdp))
 		    erts_thr_progress_leader_update(esdp);
 	    }
@@ -2959,7 +2979,9 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 								     - 1) + 1;
 				} else
 				    timeout = -1;
+                                ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
 				res = erts_tse_twait(ssi->event, timeout);
+                                ERTS_MSACC_POP_STATE_M();
 				current_time = ERTS_SCHEDULER_IS_DIRTY(esdp) ? 0 :
 				    erts_get_monotonic_time(esdp);
 			    } while (res == EINTR);
@@ -3028,9 +3050,13 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    if (working)
 		sched_wall_time_change(esdp, working = 0);
 
+	    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_CHECK_IO);
+
 	    ASSERT(!erts_port_task_have_outstanding_io_tasks());
 	    erl_sys_schedule(1); /* Might give us something to do */
 
+	    ERTS_MSACC_POP_STATE_M();
+
 	    if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
 		current_time = erts_get_monotonic_time(esdp);
 		if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
@@ -3051,6 +3077,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 		    erts_thr_progress_active(esdp, thr_prgr_active = 1);
 #endif
 		aux_work = handle_aux_work(&esdp->aux_work_data, aux_work, 1);
+                ERTS_MSACC_UPDATE_CACHE();
 #ifdef ERTS_SMP
 		if (aux_work && erts_thr_progress_update(esdp))
 		    erts_thr_progress_leader_update(esdp);
@@ -3148,8 +3175,12 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 
 	ASSERT(!erts_port_task_have_outstanding_io_tasks());
 
+	ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_CHECK_IO);
+
 	erl_sys_schedule(0);
 
+	ERTS_MSACC_POP_STATE_M();
+
 	if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
 	    ErtsMonotonicTime current_time = erts_get_monotonic_time(esdp);
 	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
@@ -7926,6 +7957,8 @@ sched_thread_func(void *vesdp)
     callbacks.wait = thr_prgr_wait;
     callbacks.finalize_wait = thr_prgr_fin_wait;
 
+    erts_msacc_init_thread("scheduler", no, 1);
+
     erts_thr_progress_register_managed_thread(esdp, &callbacks, 0);
     erts_alloc_register_scheduler(vesdp);
 #endif
@@ -9204,6 +9237,8 @@ Process *schedule(Process *p, int calls)
     Uint32 flags;
     erts_aint32_t state = 0; /* Supress warning... */
 
+    ERTS_MSACC_DECLARE_CACHE();
+
 #ifdef USE_VM_PROBES
     if (p != NULL && DTRACE_ENABLED(process_unscheduled)) {
         DTRACE_CHARBUF(process_buf, DTRACE_TERM_BUF_SIZE);
@@ -9308,6 +9343,8 @@ Process *schedule(Process *p, int calls)
 
 	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS);
 
+        ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_OTHER);
+
 	if (state & ERTS_PSFLG_FREE) {
 #ifdef ERTS_SMP
 	    ASSERT(esdp->free_process == p);
@@ -9468,7 +9505,7 @@ Process *schedule(Process *p, int calls)
 	    scheduler_wait(&fcalls, esdp, rq);
 	    flags = ERTS_RUNQ_FLGS_SET_NOB(rq, ERTS_RUNQ_FLG_EXEC);
 	    flags |= ERTS_RUNQ_FLG_EXEC;
-
+            ERTS_MSACC_UPDATE_CACHE();
 #ifdef ERTS_SMP
 	    non_empty_runq(rq);
 #endif
@@ -9483,6 +9520,8 @@ Process *schedule(Process *p, int calls)
 	     * Schedule system-level activities.
 	     */
 
+	    ERTS_MSACC_PUSH_STATE_CACHED_M();
+
 	    erts_smp_atomic32_set_relb(&function_calls, 0);
 	    fcalls = 0;
 
@@ -9490,7 +9529,9 @@ Process *schedule(Process *p, int calls)
 	    erts_sys_schedule_interrupt(0);
 #endif
 	    erts_smp_runq_unlock(rq);
+	    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_CHECK_IO);
 	    erl_sys_schedule(1);
+	    ERTS_MSACC_POP_STATE_M();
 
 	    current_time = erts_get_monotonic_time(esdp);
 	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
@@ -9568,9 +9609,12 @@ Process *schedule(Process *p, int calls)
 	    case 0:			/* No process at all */
 	    default:
 		ASSERT(qmask == 0);
+                ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_OTHER);
 		goto check_activities_to_run;
 	    }
 
+            ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_EMULATOR);
+
 	    BM_START_TIMER(system);
 
 	    /*
diff --git a/erts/emulator/beam/erl_threads.h b/erts/emulator/beam/erl_threads.h
index 34f91e2ec8..e689547d1d 100644
--- a/erts/emulator/beam/erl_threads.h
+++ b/erts/emulator/beam/erl_threads.h
@@ -2056,6 +2056,8 @@ erts_atomic64_read_dirty(erts_atomic64_t *var)
 
 #endif /* !USE_THREADS */
 
+#include "erl_msacc.h"
+
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
 ERTS_GLB_INLINE void
@@ -2414,6 +2416,7 @@ erts_cnd_wait(erts_cnd_t *cnd, erts_mtx_t *mtx)
 {
 #ifdef USE_THREADS
     int res;
+    ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_SLEEP);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_unlock(&mtx->lc);
 #endif
@@ -2432,6 +2435,7 @@ erts_cnd_wait(erts_cnd_t *cnd, erts_mtx_t *mtx)
 #endif
     if (res != 0 && res != EINTR)
 	erts_thr_fatal_error(res, "wait on condition variable");
+    ERTS_MSACC_POP_STATE();
 #endif
 }
 
@@ -3488,7 +3492,11 @@ ERTS_GLB_INLINE void erts_tse_reset(erts_tse_t *ep)
 ERTS_GLB_INLINE int erts_tse_wait(erts_tse_t *ep)
 {
 #ifdef USE_THREADS
-    return ethr_event_wait(&((ethr_ts_event *) ep)->event);
+    int res;
+    ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_SLEEP);
+    res = ethr_event_wait(&((ethr_ts_event *) ep)->event);
+    ERTS_MSACC_POP_STATE();
+    return res;
 #else
     return ENOTSUP;
 #endif
@@ -3497,7 +3505,11 @@ ERTS_GLB_INLINE int erts_tse_wait(erts_tse_t *ep)
 ERTS_GLB_INLINE int erts_tse_swait(erts_tse_t *ep, int spincount)
 {
 #ifdef USE_THREADS
-    return ethr_event_swait(&((ethr_ts_event *) ep)->event, spincount);
+    int res;
+    ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_SLEEP);
+    res = ethr_event_swait(&((ethr_ts_event *) ep)->event, spincount);
+    ERTS_MSACC_POP_STATE();
+    return res;
 #else
     return ENOTSUP;
 #endif
@@ -3506,8 +3518,12 @@ ERTS_GLB_INLINE int erts_tse_swait(erts_tse_t *ep, int spincount)
 ERTS_GLB_INLINE int erts_tse_twait(erts_tse_t *ep, Sint64 tmo)
 {
 #ifdef USE_THREADS
-    return ethr_event_twait(&((ethr_ts_event *) ep)->event,
-			    (ethr_sint64_t) tmo);
+    int res;
+    ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_SLEEP);
+    res = ethr_event_twait(&((ethr_ts_event *) ep)->event,
+                           (ethr_sint64_t) tmo);
+    ERTS_MSACC_POP_STATE();
+    return res;
 #else
     return ENOTSUP;
 #endif
@@ -3516,9 +3532,13 @@ ERTS_GLB_INLINE int erts_tse_twait(erts_tse_t *ep, Sint64 tmo)
 ERTS_GLB_INLINE int erts_tse_stwait(erts_tse_t *ep, int spincount, Sint64 tmo)
 {
 #ifdef USE_THREADS
-    return ethr_event_stwait(&((ethr_ts_event *) ep)->event,
-			     spincount,
-			     (ethr_sint64_t) tmo);
+    int res;
+    ERTS_MSACC_PUSH_AND_SET_STATE(ERTS_MSACC_STATE_SLEEP);
+    res = ethr_event_stwait(&((ethr_ts_event *) ep)->event,
+                            spincount,
+                            (ethr_sint64_t) tmo);
+    ERTS_MSACC_POP_STATE();
+    return res;
 #else
     return ENOTSUP;
 #endif
diff --git a/erts/emulator/beam/erl_time.h b/erts/emulator/beam/erl_time.h
index 93a0d556bf..5242063550 100644
--- a/erts/emulator/beam/erl_time.h
+++ b/erts/emulator/beam/erl_time.h
@@ -142,6 +142,8 @@ erts_time_unit_conversion(Uint64 value,
 			  Uint32 from_time_unit,
 			  Uint32 to_time_unit);
 
+ErtsSysPerfCounter erts_perf_counter_unit(void);
+
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
 ERTS_GLB_INLINE Uint64
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 668dbb5daa..98159fdf72 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -1749,7 +1749,7 @@ erts_get_monotonic_time(ErtsSchedulerData *esdp)
 {
     ErtsMonotonicTime mtime = time_sup.r.o.get_time();
     update_last_mtime(esdp, mtime);
-    return mtime;    
+    return mtime;
 }
 
 ErtsMonotonicTime
@@ -2435,9 +2435,19 @@ BIF_RETTYPE os_system_time_0(BIF_ALIST_0)
     BIF_RET(make_time_val(BIF_P, stime));
 }
 
-BIF_RETTYPE os_system_time_1(BIF_ALIST_0)
+BIF_RETTYPE os_system_time_1(BIF_ALIST_1)
 {
     ErtsSystemTime stime = erts_os_system_time();
     BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, stime, 0));
 }
 
+BIF_RETTYPE
+os_perf_counter_0(BIF_ALIST_0)
+{
+    BIF_RET(make_time_val(BIF_P, erts_sys_perf_counter()));
+}
+
+BIF_RETTYPE erts_internal_perf_counter_unit_0(BIF_ALIST_0)
+{
+    BIF_RET(make_time_val(BIF_P, erts_sys_perf_counter_unit()));
+}
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 3f5925765d..e8a7573e86 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -1448,6 +1448,8 @@ ERTS_GLB_FORCE_INLINE int erts_is_literal(Eterm tptr, Eterm *ptr)
 
 #endif
 
+Eterm erts_msacc_request(Process *c_p, int action, Eterm *threads);
+
 /*
 ** Call_trace uses this API for the parameter matching functions
 */
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 07578fd24e..41b0fcdd1b 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -706,6 +706,7 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 
     error_number = error_type = 0;
     if (driver->start) {
+        ERTS_MSACC_PUSH_STATE_M();
 	if (IS_TRACED_FL(port, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(port, am_in, am_start);
 	}
@@ -716,6 +717,7 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
             DTRACE3(driver_start, process_str, driver->name, port_str);
         }
 #endif
+	ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
 	fpe_was_unmasked = erts_block_fpe();
 	drv_data = (*driver->start)(ERTS_Port2ErlDrvPort(port), name, opts);
 	if (((SWord) drv_data) == -1)
@@ -735,6 +737,7 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 	}
 
 	erts_unblock_fpe(fpe_was_unmasked);
+	ERTS_MSACC_POP_STATE_M();
 	port->caller = NIL;
 	if (IS_TRACED_FL(port, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(port, am_out, am_start);
@@ -1710,6 +1713,7 @@ call_driver_outputv(int bang_op,
     else {
 	ErtsSchedulerData *esdp = erts_get_scheduler_data();
 	ErlDrvSizeT size = evp->size;
+	ERTS_MSACC_PUSH_AND_SET_STATE_M(ERTS_MSACC_STATE_PORT);
 
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt)	
 			   || ERTS_IS_CRASH_DUMPING);
@@ -1730,6 +1734,8 @@ call_driver_outputv(int bang_op,
 	    esdp->io.out += (Uint64) size;
 	else
 	    erts_atomic64_add_nob(&bytes_out, (erts_aint64_t) size);
+
+	ERTS_MSACC_POP_STATE_M();
     }
 }
 
@@ -1810,6 +1816,7 @@ call_driver_output(int bang_op,
 	send_badsig(prt);
     else {
 	ErtsSchedulerData *esdp = erts_get_scheduler_data();
+        ERTS_MSACC_PUSH_AND_SET_STATE_M(ERTS_MSACC_STATE_PORT);
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt)	
 			   || ERTS_IS_CRASH_DUMPING);
 
@@ -1829,6 +1836,8 @@ call_driver_output(int bang_op,
 	    esdp->io.out += (Uint64) size;
 	else
 	    erts_atomic64_add_nob(&bytes_out, (erts_aint64_t) size);
+
+	ERTS_MSACC_POP_STATE_M();
     }
 }
 
@@ -3473,6 +3482,7 @@ static void flush_port(Port *p)
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
 
     if (p->drv_ptr->flush != NULL) {
+        ERTS_MSACC_PUSH_STATE_M();
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(driver_flush)) {
             DTRACE_FORMAT_COMMON_PID_AND_PORT(ERTS_PORT_GET_CONNECTED(p), p)
@@ -3482,9 +3492,11 @@ static void flush_port(Port *p)
         if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(p, am_in, am_flush);
 	}
+        ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
 	fpe_was_unmasked = erts_block_fpe();
 	(*p->drv_ptr->flush)((ErlDrvData)p->drv_data);
 	erts_unblock_fpe(fpe_was_unmasked);
+	ERTS_MSACC_POP_STATE_M();
         if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(p, am_out, am_flush);
 	}
@@ -3532,6 +3544,7 @@ terminate_port(Port *prt)
     drv = prt->drv_ptr;
     if ((drv != NULL) && (drv->stop != NULL)) {
 	int fpe_was_unmasked = erts_block_fpe();
+	ERTS_MSACC_PUSH_AND_SET_STATE_M(ERTS_MSACC_STATE_PORT);
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(driver_stop)) {
             DTRACE_FORMAT_COMMON_PID_AND_PORT(connected_id, prt)
@@ -3540,6 +3553,7 @@ terminate_port(Port *prt)
 #endif
 	(*drv->stop)((ErlDrvData)prt->drv_data);
 	erts_unblock_fpe(fpe_was_unmasked);
+	ERTS_MSACC_POP_STATE_M();
 #ifdef ERTS_SMP
 	if (prt->xports)
 	    erts_port_handle_xports(prt);
@@ -3850,6 +3864,7 @@ call_driver_control(Eterm caller,
 		    ErlDrvSizeT *from_size)
 {
     ErlDrvSSizeT cres;
+    ERTS_MSACC_PUSH_STATE_M();
 
     if (!prt->drv_ptr->control)
 	return ERTS_PORT_OP_BADARG;
@@ -3863,6 +3878,8 @@ call_driver_control(Eterm caller,
                 command, size);
     }
 #endif
+    
+    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
 
     prt->caller = caller;
     cres = prt->drv_ptr->control((ErlDrvData) prt->drv_data,
@@ -3873,6 +3890,8 @@ call_driver_control(Eterm caller,
 				 *from_size);
     prt->caller = NIL;
 
+    ERTS_MSACC_POP_STATE_M();
+
     if (cres < 0)
 	return ERTS_PORT_OP_BADARG;
 
@@ -4260,6 +4279,7 @@ call_driver_call(Eterm caller,
 		 unsigned *ret_flagsp)
 {
     ErlDrvSSizeT cres;
+    ERTS_MSACC_PUSH_STATE_M();
 
     if (!prt->drv_ptr->call)
 	return ERTS_PORT_OP_BADARG;
@@ -4275,6 +4295,8 @@ call_driver_call(Eterm caller,
     }
 #endif
 
+    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
+
     prt->caller = caller;
     cres = prt->drv_ptr->call((ErlDrvData) prt->drv_data,
 			      command,
@@ -4285,6 +4307,8 @@ call_driver_call(Eterm caller,
 			      ret_flagsp);
     prt->caller = NIL;
 
+    ERTS_MSACC_POP_STATE_M();
+
     if (cres <= 0
 	|| ((byte) (*resp_bufp)[0]) != VERSION_MAGIC)
 	return ERTS_PORT_OP_BADARG;
@@ -4988,6 +5012,7 @@ int get_port_flags(ErlDrvPort ix)
 void erts_raw_port_command(Port* p, byte* buf, Uint len)
 {
     int fpe_was_unmasked;
+    ERTS_MSACC_PUSH_STATE_M();
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
@@ -5008,9 +5033,11 @@ void erts_raw_port_command(Port* p, byte* buf, Uint len)
         DTRACE4(driver_output, "-raw-", port_str, p->name, len);
     }
 #endif
+    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
     fpe_was_unmasked = erts_block_fpe();
     (*p->drv_ptr->output)((ErlDrvData)p->drv_data, (char*) buf, (int) len);
     erts_unblock_fpe(fpe_was_unmasked);
+    ERTS_MSACC_POP_STATE_M();
 }
 
 int async_ready(Port *p, void* data)
@@ -5022,6 +5049,7 @@ int async_ready(Port *p, void* data)
     if (p) {
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
 	if (p->drv_ptr->ready_async != NULL) {
+	    ERTS_MSACC_PUSH_AND_SET_STATE_M(ERTS_MSACC_STATE_PORT);
 #ifdef USE_VM_PROBES
             if (DTRACE_ENABLED(driver_ready_async)) {
                 DTRACE_FORMAT_COMMON_PID_AND_PORT(ERTS_PORT_GET_CONNECTED(p), p)
@@ -5030,6 +5058,7 @@ int async_ready(Port *p, void* data)
 #endif
 	    (*p->drv_ptr->ready_async)((ErlDrvData)p->drv_data, data);
 	    need_free = 0;
+	    ERTS_MSACC_POP_STATE_M();
 
 	}
 	erts_port_driver_callback_epilogue(p, NULL);
@@ -7053,6 +7082,7 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
     void (*callback)(ErlDrvData drv_data, ErlDrvMonitor *monitor);
     ErlDrvMonitor drv_monitor;
     int fpe_was_unmasked;
+    ERTS_MSACC_PUSH_STATE_M();
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
     ASSERT(prt->drv_ptr != NULL);    
@@ -7064,6 +7094,7 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
     callback = prt->drv_ptr->process_exit;
     ASSERT(callback != NULL);
     ref_to_driver_monitor(ref,&drv_monitor);
+    ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_PORT);
     DRV_MONITOR_UNLOCK_PDL(prt);
 #ifdef USE_VM_PROBES
     if (DTRACE_ENABLED(driver_process_exit)) {
@@ -7075,6 +7106,7 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
     (*callback)((ErlDrvData) (prt->drv_data), &drv_monitor);
     erts_unblock_fpe(fpe_was_unmasked);
     DRV_MONITOR_LOCK_PDL(prt);
+    ERTS_MSACC_POP_STATE_M();
     /* remove monitor *after* callback */
     rmon = erts_remove_monitor(&ERTS_P_MONITORS(prt), ref);
     DRV_MONITOR_UNLOCK_PDL(prt);
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 081c4108a0..9e53b4bfcc 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -988,6 +988,13 @@ move Discarded x==0 | move Something x==0 => move Something x=0
 
 %endif
 
+call_ext u==0 u$func:os:perf_counter/0 => \
+    i_perf_counter
+call_ext_last u==0 u$func:os:perf_counter/0 D => \
+    i_perf_counter | deallocate_return D
+call_ext_only u==0 u$func:os:perf_counter/0 => \
+    i_perf_counter | return
+
 #
 # The general case for BIFs that have no special instructions.
 # A BIF used in the tail must be followed by a return instruction.
@@ -1027,6 +1034,8 @@ i_apply_fun_only
 
 i_hibernate
 
+i_perf_counter
+
 call_bif e
 
 #
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index 279e4db0af..e77b4b2dc8 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -136,6 +136,17 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType;
 #  define ERTS_LIKELY(BOOL)   (BOOL)
 #  define ERTS_UNLIKELY(BOOL) (BOOL)
 #endif
+
+#if ERTS_AT_LEAST_GCC_VSN__(2, 96, 0)
+#ifndef __llvm__
+#  define ERTS_WRITE_UNLIKELY(X) X __attribute__ ((section ("ERTS_LOW_WRITE") ))
+#else
+#  define ERTS_WRITE_UNLIKELY(X) X __attribute__ ((section ("__DATA,ERTS_LOW_WRITE") ))
+#endif
+#else
+#  define ERTS_WRITE_UNLIKELY(X) X
+#endif
+
 #ifdef __GNUC__
 #  if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 5)
 #    define ERTS_DECLARE_DUMMY(X) X __attribute__ ((unused))
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 0ab6661c9f..48cb39333a 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -278,9 +278,14 @@ ErtsMonotonicTime
 erts_check_next_timeout_time(ErtsSchedulerData *esdp)
 {
     ErtsTimerWheel *tiw = esdp->timer_wheel;
+    ErtsMonotonicTime time;
+    ERTS_MSACC_DECLARE_CACHE_X();
     if (tiw->true_next_timeout_time)
 	return tiw->next_timeout_time;
-    return find_next_timeout(esdp, tiw, 1, 0, 0);
+    ERTS_MSACC_PUSH_AND_SET_STATE_CACHED_X(ERTS_MSACC_STATE_TIMERS);
+    time = find_next_timeout(esdp, tiw, 1, 0, 0);
+    ERTS_MSACC_POP_STATE_M_X();
+    return time;
 }
 
 #ifndef ERTS_TW_DEBUG
@@ -336,6 +341,7 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 {
     int tiw_pos_ix, slots, yielded_slot_restarted, yield_count;
     ErtsMonotonicTime bump_to, tmp_slots, old_pos;
+    ERTS_MSACC_PUSH_AND_SET_STATE_M_X(ERTS_MSACC_STATE_TIMERS);
 
     yield_count = ERTS_TWHEEL_BUMP_YIELD_LIMIT;
 
@@ -371,6 +377,7 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 		tiw->next_timeout_time = curr_time + ERTS_MONOTONIC_DAY;
 		tiw->pos = bump_to;
 		tiw->yield_slot = ERTS_TWHEEL_SLOT_INACTIVE;
+                ERTS_MSACC_POP_STATE_M_X();
 		return;
 	    }
 
@@ -382,6 +389,7 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 		    tiw->yield_slot = ERTS_TWHEEL_SLOT_AT_ONCE;
 		    tiw->true_next_timeout_time = 1;
 		    tiw->next_timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(old_pos);
+                    ERTS_MSACC_POP_STATE_M_X();
 		    return;
 		}
 
@@ -400,8 +408,10 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 		p = tiw->at_once.head;
 	    }
 
-	    if (tiw->pos >= bump_to)
+	    if (tiw->pos >= bump_to) {
+                ERTS_MSACC_POP_STATE_M_X();
 		break;
+            }
 
 	    if (tiw->nto == 0)
 		goto empty_wheel;
@@ -478,6 +488,7 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 			    tiw->yield_slot = tiw_pos_ix;
 			    tiw->yield_slots_left = slots;
 			    tiw->yield_start_pos = old_pos;
+                            ERTS_MSACC_POP_STATE_M_X();
 			    return; /* Yield! */
 			}
 
@@ -500,6 +511,7 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 
     /* Search at most two seconds ahead... */
     (void) find_next_timeout(NULL, tiw, 0, curr_time, ERTS_SEC_TO_MONOTONIC(2));
+    ERTS_MSACC_POP_STATE_M_X();
 }
 
 Uint
@@ -569,6 +581,7 @@ erts_twheel_set_timer(ErtsTimerWheel *tiw,
 		      ErtsMonotonicTime timeout_pos)
 {
     ErtsMonotonicTime timeout_time;
+    ERTS_MSACC_PUSH_AND_SET_STATE_M_X(ERTS_MSACC_STATE_TIMERS);
 
     p->u.func.timeout = timeout;
     p->u.func.cancel = cancel;
@@ -612,6 +625,7 @@ erts_twheel_set_timer(ErtsTimerWheel *tiw,
 	tiw->true_next_timeout_time = 1;
 	tiw->next_timeout_time = timeout_time;
     }
+    ERTS_MSACC_POP_STATE_M_X();
 }
 
 void
@@ -620,11 +634,13 @@ erts_twheel_cancel_timer(ErtsTimerWheel *tiw, ErtsTWheelTimer *p)
     if (p->slot != ERTS_TWHEEL_SLOT_INACTIVE) {
 	ErlCancelProc cancel;
 	void *arg;
+        ERTS_MSACC_PUSH_AND_SET_STATE_M_X(ERTS_MSACC_STATE_TIMERS);
 	remove_timer(tiw, p);
 	cancel = p->u.func.cancel;
 	arg = p->u.func.arg;
 	if (cancel)
 	    (*cancel)(arg);
+        ERTS_MSACC_POP_STATE_M_X();
     }
 }