Merge branch 'egil/lcnt-refactor/OTP-12846'

* egil/lcnt-refactor/OTP-12846:
  erts: Refactor LCNT

5 files changed, 321 insertions, 389 deletions

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 397c68e199..8a675302b2 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -4296,59 +4296,41 @@ BIF_RETTYPE erts_debug_lock_counters_1(BIF_ALIST_1)
 
 	BIF_RET(am_ok);
     } else if (is_tuple(BIF_ARG_1)) {
-	Eterm* tp = tuple_val(BIF_ARG_1);
+        Eterm* ptr = tuple_val(BIF_ARG_1);
+
+        if ((arityval(ptr[0]) == 2) && (ptr[2] == am_false || ptr[2] == am_true)) {
+            int lock_opt = 0, enable = (ptr[2] == am_true) ? 1 : 0;
+            if (ERTS_IS_ATOM_STR("copy_save", ptr[1])) {
+                lock_opt = ERTS_LCNT_OPT_COPYSAVE;
+            } else if (ERTS_IS_ATOM_STR("process_locks", ptr[1])) {
+                lock_opt = ERTS_LCNT_OPT_PROCLOCK;
+            } else if (ERTS_IS_ATOM_STR("port_locks", ptr[1])) {
+                lock_opt = ERTS_LCNT_OPT_PORTLOCK;
+            } else if (ERTS_IS_ATOM_STR("suspend", ptr[1])) {
+                lock_opt = ERTS_LCNT_OPT_SUSPEND;
+            } else if (ERTS_IS_ATOM_STR("location", ptr[1])) {
+                lock_opt = ERTS_LCNT_OPT_LOCATION;
+            } else {
+                BIF_ERROR(BIF_P, BADARG);
+            }
 
-	switch (arityval(tp[0])) {
-	    case 2: {
-		int opt = 0;
-		int val = 0;
-		if (ERTS_IS_ATOM_STR("copy_save", tp[1])) {
-		    opt = ERTS_LCNT_OPT_COPYSAVE;
-		} else if (ERTS_IS_ATOM_STR("process_locks", tp[1])) {
-		    opt = ERTS_LCNT_OPT_PROCLOCK;
-		} else if (ERTS_IS_ATOM_STR("port_locks", tp[1])) {
-		    opt = ERTS_LCNT_OPT_PORTLOCK;
-		} else if (ERTS_IS_ATOM_STR("suspend", tp[1])) {
-		    opt = ERTS_LCNT_OPT_SUSPEND;
-		} else if (ERTS_IS_ATOM_STR("location", tp[1])) {
-		    opt = ERTS_LCNT_OPT_LOCATION;
-		} else {
-		    BIF_ERROR(BIF_P, BADARG);
-		}
-		if (tp[2] == am_true) {
-		    val = 1;
-		} else if (tp[2] == am_false) {
-		    val = 0;
-		} else {
-		    BIF_ERROR(BIF_P, BADARG);
-		}
+            erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
+            erts_smp_thr_progress_block();
 
-		erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-		erts_smp_thr_progress_block();
-		
-		if (val) {
-		    res = erts_lcnt_set_rt_opt(opt) ? am_true : am_false;
-		} else {
-		    res = erts_lcnt_clear_rt_opt(opt) ? am_true : am_false;
-		}
+            if (enable) res = erts_lcnt_set_rt_opt(lock_opt) ? am_true : am_false;
+            else res = erts_lcnt_clear_rt_opt(lock_opt) ? am_true : am_false;
+            
 #ifdef ERTS_SMP
-		if (res != tp[2]) {
-		    if (opt == ERTS_LCNT_OPT_PORTLOCK) {
-			erts_lcnt_enable_io_lock_count(val);
-		    } else if (opt == ERTS_LCNT_OPT_PROCLOCK) {
-			erts_lcnt_enable_proc_lock_count(val);
-		    }
-		}
+            if (res != ptr[2] && lock_opt == ERTS_LCNT_OPT_PORTLOCK) {
+                erts_lcnt_enable_io_lock_count(enable);
+            } else if (res != ptr[2] && lock_opt == ERTS_LCNT_OPT_PROCLOCK) {
+                erts_lcnt_enable_proc_lock_count(enable);
+            }
 #endif
-		erts_smp_thr_progress_unblock();
-		erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-		BIF_RET(res);
-		break;
-	    }
-     
-	    default:
-	    break;
-	}
+            erts_smp_thr_progress_unblock();
+            erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
+            BIF_RET(res);
+        }
     } 
 
 #endif 
diff --git a/erts/emulator/beam/erl_lock_count.c b/erts/emulator/beam/erl_lock_count.c
index c6d8f4df95..c4956d8569 100644
--- a/erts/emulator/beam/erl_lock_count.c
+++ b/erts/emulator/beam/erl_lock_count.c
@@ -20,7 +20,7 @@
 /*
  * Description:	Statistics for locks.
  *
- * Author:	Bj�rn-Egil Dahlberg
+ * Author:	Björn-Egil Dahlberg
  * Date:	2008-07-03
  */
 
@@ -49,7 +49,7 @@ const char *str_undefined = "undefined";
 
 static ethr_tsd_key lcnt_thr_data_key;
 static int lcnt_n_thr;
-static erts_lcnt_thread_data_t *lcnt_thread_data[4096]; 
+static erts_lcnt_thread_data_t *lcnt_thread_data[2048];
 
 /* local functions */
 
@@ -83,12 +83,12 @@ static ERTS_INLINE int lcnt_log2(Uint64 v) {
 
 static char* lcnt_lock_type(Uint16 flag) {
     switch(flag & ERTS_LCNT_LT_ALL) {
-    case ERTS_LCNT_LT_SPINLOCK:	  return "spinlock";
-    case ERTS_LCNT_LT_RWSPINLOCK: return "rw_spinlock";
-    case ERTS_LCNT_LT_MUTEX:      return "mutex";
-    case ERTS_LCNT_LT_RWMUTEX:	  return "rw_mutex";
-    case ERTS_LCNT_LT_PROCLOCK:	  return "proclock";
-    default:                      return "";
+        case ERTS_LCNT_LT_SPINLOCK:   return "spinlock";
+        case ERTS_LCNT_LT_RWSPINLOCK: return "rw_spinlock";
+        case ERTS_LCNT_LT_MUTEX:      return "mutex";
+        case ERTS_LCNT_LT_RWMUTEX:    return "rw_mutex";
+        case ERTS_LCNT_LT_PROCLOCK:   return "proclock";
+        default:                      return "";
     }
 }
 
@@ -116,15 +116,15 @@ static void lcnt_time(erts_lcnt_time_t *time) {
 static void lcnt_time_diff(erts_lcnt_time_t *d, erts_lcnt_time_t *t1, erts_lcnt_time_t *t0) {
     long ds;
     long dns;
-    
+
     ds  = t1->s  - t0->s;
     dns = t1->ns - t0->ns;
-	
+
     /* the difference should not be able to get bigger than 1 sec in ns*/
-    
+
     if (dns < 0) {
-	ds  -= 1;
-	dns += 1000000000LL;
+        ds  -= 1;
+        dns += 1000000000LL;
     }
 
     ASSERT(ds >= 0);
@@ -145,7 +145,7 @@ static void lcnt_time_add(erts_lcnt_time_t *t, erts_lcnt_time_t *d) {
 
 static erts_lcnt_thread_data_t *lcnt_thread_data_alloc(void) {
     erts_lcnt_thread_data_t *eltd;
-   
+
     eltd = (erts_lcnt_thread_data_t*)malloc(sizeof(erts_lcnt_thread_data_t));
     if (!eltd) {
         ERTS_INTERNAL_ERROR("Lock counter failed to allocate memory!");
@@ -164,7 +164,6 @@ static erts_lcnt_thread_data_t *lcnt_get_thread_data(void) {
     return (erts_lcnt_thread_data_t *)ethr_tsd_get(lcnt_thr_data_key);
 }
 
-
 /* debug */
 
 #if 0
@@ -183,15 +182,15 @@ static void print_lock_x(erts_lcnt_lock_t *lock, Uint16 flag, char *action) {
     type = lcnt_lock_type(lock->flag);
     r_state = ethr_atomic_read(&lock->r_state);
     w_state = ethr_atomic_read(&lock->w_state);
-    
+
     if (lock->flag & flag) {
         erts_fprintf(stderr,"%10s [%24s] [r/w state %4ld/%4ld] %2s id %T\r\n",
-		action,
-		lock->name,
-		r_state,
-		w_state,
-		type,
-		lock->id);
+                action,
+                lock->name,
+                r_state,
+                w_state,
+                type,
+                lock->id);
     }
 }
 #endif
@@ -201,18 +200,18 @@ static erts_lcnt_lock_stats_t *lcnt_get_lock_stats(erts_lcnt_lock_t *lock, char
     erts_lcnt_lock_stats_t *stats = NULL;
 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_LOCATION) {
-	for (i = 0; i < lock->n_stats; i++) {
-	    if ((lock->stats[i].file == file) && (lock->stats[i].line == line)) {
-		return &(lock->stats[i]);
-	    }
-	}
-	if (lock->n_stats < ERTS_LCNT_MAX_LOCK_LOCATIONS) {
-	    stats = &lock->stats[lock->n_stats];
-	    lock->n_stats++;
-	    stats->file = file;
-	    stats->line = line;
-	    return stats;
-	}
+        for (i = 0; i < lock->n_stats; i++) {
+            if ((lock->stats[i].file == file) && (lock->stats[i].line == line)) {
+                return &(lock->stats[i]);
+            }
+        }
+        if (lock->n_stats < ERTS_LCNT_MAX_LOCK_LOCATIONS) {
+            stats = &lock->stats[lock->n_stats];
+            lock->n_stats++;
+            stats->file = file;
+            stats->line = line;
+            return stats;
+        }
     }
     return &lock->stats[0];
 }
@@ -222,53 +221,48 @@ static void lcnt_update_stats_hist(erts_lcnt_hist_t *hist, erts_lcnt_time_t *tim
     unsigned long r;
 
     if (time_wait->s > 0 || time_wait->ns > ERTS_LCNT_HISTOGRAM_MAX_NS) {
-	idx = ERTS_LCNT_HISTOGRAM_SLOT_SIZE - 1;
+        idx = ERTS_LCNT_HISTOGRAM_SLOT_SIZE - 1;
     } else {
-	r = time_wait->ns >> ERTS_LCNT_HISTOGRAM_RSHIFT;
-	if (r) idx = lcnt_log2(r);
-	else idx = 0;
+        r = time_wait->ns >> ERTS_LCNT_HISTOGRAM_RSHIFT;
+        if (r) idx = lcnt_log2(r);
+        else idx = 0;
     }
     hist->ns[idx]++;
 }
 
 static void lcnt_update_stats(erts_lcnt_lock_stats_t *stats, int lock_in_conflict,
-	                      erts_lcnt_time_t *time_wait) {
-    
+        erts_lcnt_time_t *time_wait) {
+
     ethr_atomic_inc(&stats->tries);
 
     if (lock_in_conflict)
-	ethr_atomic_inc(&stats->colls);
+        ethr_atomic_inc(&stats->colls);
 
     if (time_wait) {
-	lcnt_time_add(&(stats->timer), time_wait);
-	stats->timer_n++;
-	lcnt_update_stats_hist(&stats->hist,time_wait);
+        lcnt_time_add(&(stats->timer), time_wait);
+        stats->timer_n++;
+        lcnt_update_stats_hist(&stats->hist,time_wait);
     }
 }
 
-/* 
- * interface 
- */
+/* interface */
 
 void erts_lcnt_init() {
     erts_lcnt_thread_data_t *eltd = NULL;
-    
+
     /* init lock */
     if (ethr_mutex_init(&lcnt_data_lock) != 0) abort();
 
     /* init tsd */    
     lcnt_n_thr = 0;
-
     ethr_tsd_key_create(&lcnt_thr_data_key,"lcnt_data");
 
     lcnt_lock();
 
-    erts_lcnt_rt_options = ERTS_LCNT_OPT_PROCLOCK | ERTS_LCNT_OPT_LOCATION;
-    
+    erts_lcnt_rt_options = ERTS_LCNT_OPT_LOCATION | ERTS_LCNT_OPT_PROCLOCK;
     eltd = lcnt_thread_data_alloc();
-
     ethr_tsd_set(lcnt_thr_data_key, eltd);
-    
+
     /* init lcnt structure */
     erts_lcnt_data = (erts_lcnt_data_t*)malloc(sizeof(erts_lcnt_data_t));
     if (!erts_lcnt_data) {
@@ -293,7 +287,7 @@ void erts_lcnt_late_init() {
 
 erts_lcnt_lock_list_t *erts_lcnt_list_init(void) {
     erts_lcnt_lock_list_t *list;
-    
+
     list = (erts_lcnt_lock_list_t*)malloc(sizeof(erts_lcnt_lock_list_t));
     if (!list) {
         ERTS_INTERNAL_ERROR("Lock counter failed to allocate memory!");
@@ -307,14 +301,14 @@ erts_lcnt_lock_list_t *erts_lcnt_list_init(void) {
 /* only do this on the list with the deleted locks! */
 void erts_lcnt_list_clear(erts_lcnt_lock_list_t *list) {
     erts_lcnt_lock_t *lock = NULL,
-		     *next = NULL;
+                     *next = NULL;
 
     lock = list->head;
-    
+
     while(lock != NULL) {
-	next = lock->next;
-	free(lock);
-	lock = next;
+        next = lock->next;
+        free(lock);
+        lock = next;
     }
 
     list->head = NULL;
@@ -327,26 +321,25 @@ void erts_lcnt_list_insert(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock)
 
     tail = list->tail;
     if (tail) {
-	tail->next = lock;
-	lock->prev = tail;
+        tail->next = lock;
+        lock->prev = tail;
     } else {
-	list->head = lock;
-	lock->prev = NULL;
-	ASSERT(!lock->next);
+        list->head = lock;
+        lock->prev = NULL;
+        ASSERT(!lock->next);
     }
     lock->next = NULL;
     list->tail = lock;
-    
+
     list->n++;
 }
 
 void erts_lcnt_list_delete(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock) {
-
     if (lock->next) lock->next->prev = lock->prev;
     if (lock->prev) lock->prev->next = lock->next;
     if (list->head == lock) list->head = lock->next;
     if (list->tail == lock) list->tail = lock->prev;
-    
+
     lock->prev = NULL;
     lock->next = NULL;
     list->n--;
@@ -364,12 +357,9 @@ void erts_lcnt_init_lock(erts_lcnt_lock_t *lock, char *name, Uint16 flag ) {
 
 void erts_lcnt_init_lock_x(erts_lcnt_lock_t *lock, char *name, Uint16 flag, Eterm id) { 
     int i;
-    if (!name) {
-	lock->flag = 0;
-	return;
-    }
+    if (name == NULL) { ERTS_LCNT_CLEAR_FLAG(lock); return; }
     lcnt_lock();
-    
+
     lock->next = NULL;
     lock->prev = NULL;
     lock->flag = flag;
@@ -378,46 +368,55 @@ void erts_lcnt_init_lock_x(erts_lcnt_lock_t *lock, char *name, Uint16 flag, Eter
 
     ethr_atomic_init(&lock->r_state, 0);
     ethr_atomic_init(&lock->w_state, 0);
-    
 #ifdef DEBUG
     ethr_atomic_init(&lock->flowstate, 0);
 #endif
-    
+
     lock->n_stats = 1;
 
     for (i = 0; i < ERTS_LCNT_MAX_LOCK_LOCATIONS; i++) {
-	lcnt_clear_stats(&lock->stats[i]);
+        lcnt_clear_stats(&lock->stats[i]);
     }
 
     erts_lcnt_list_insert(erts_lcnt_data->current_locks, lock);
     lcnt_unlock();
 }
-
+/* init empty, instead of zero struct */
+void erts_lcnt_init_lock_empty(erts_lcnt_lock_t *lock) {
+    lock->next = NULL;
+    lock->prev = NULL;
+    lock->flag = 0;
+    lock->name = NULL;
+    lock->id   = NIL;
+    ethr_atomic_init(&lock->r_state, 0);
+    ethr_atomic_init(&lock->w_state, 0);
+#ifdef DEBUG
+    ethr_atomic_init(&lock->flowstate, 0);
+#endif
+    lock->n_stats = 0;
+    sys_memzero(lock->stats, sizeof(lock->stats));
+}
+/* destroy lock */
 void erts_lcnt_destroy_lock(erts_lcnt_lock_t *lock) {
-    erts_lcnt_lock_t *deleted_lock;
-
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
-
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
     lcnt_lock();
 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_COPYSAVE) {
-	/* copy structure and insert the copy */
-
-	deleted_lock = (erts_lcnt_lock_t*)malloc(sizeof(erts_lcnt_lock_t));
+        erts_lcnt_lock_t *deleted_lock;
+        /* copy structure and insert the copy */
+        deleted_lock = (erts_lcnt_lock_t*)malloc(sizeof(erts_lcnt_lock_t));
         if (!deleted_lock) {
             ERTS_INTERNAL_ERROR("Lock counter failed to allocate memory!");
         }
-	memcpy(deleted_lock, lock, sizeof(erts_lcnt_lock_t));
-
-	deleted_lock->next = NULL;
-	deleted_lock->prev = NULL;
-
-	erts_lcnt_list_insert(erts_lcnt_data->deleted_locks, deleted_lock);
+        memcpy(deleted_lock, lock, sizeof(erts_lcnt_lock_t));
+        deleted_lock->next = NULL;
+        deleted_lock->prev = NULL;
+        erts_lcnt_list_insert(erts_lcnt_data->deleted_locks, deleted_lock);
     }
     /* delete original */
     erts_lcnt_list_delete(erts_lcnt_data->current_locks, lock);
-    lock->flag = 0;
-    
+    ERTS_LCNT_CLEAR_FLAG(lock);
+
     lcnt_unlock();
 }
 
@@ -426,16 +425,15 @@ void erts_lcnt_destroy_lock(erts_lcnt_lock_t *lock) {
 void erts_lcnt_lock_opt(erts_lcnt_lock_t *lock, Uint16 option) {
     erts_aint_t r_state = 0, w_state = 0;
     erts_lcnt_thread_data_t *eltd;
-    
+
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
 
     eltd = lcnt_get_thread_data();
-
     ASSERT(eltd);
-    
+
     w_state = ethr_atomic_read(&lock->w_state);
-    
+
     if (option & ERTS_LCNT_LO_WRITE) {
         r_state = ethr_atomic_read(&lock->r_state);
         ethr_atomic_inc( &lock->w_state);
@@ -443,48 +441,47 @@ void erts_lcnt_lock_opt(erts_lcnt_lock_t *lock, Uint16 option) {
     if (option & ERTS_LCNT_LO_READ) {
         ethr_atomic_inc( &lock->r_state);
     }
-    
+
     /* we cannot acquire w_lock if either w or r are taken */
     /* we cannot acquire r_lock if w_lock is taken */	
-    
+
     if ((w_state > 0) || (r_state > 0)) {
-	eltd->lock_in_conflict = 1;
-	if (eltd->timer_set == 0) {
-	    lcnt_time(&eltd->timer);
-	}
-	eltd->timer_set++;
+        eltd->lock_in_conflict = 1;
+        if (eltd->timer_set == 0) {
+            lcnt_time(&eltd->timer);
+        }
+        eltd->timer_set++;
     } else {
-	eltd->lock_in_conflict = 0;
+        eltd->lock_in_conflict = 0;
     }
 }
 
 void erts_lcnt_lock(erts_lcnt_lock_t *lock) {
     erts_aint_t w_state;
     erts_lcnt_thread_data_t *eltd;
-    
+
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
 
     w_state = ethr_atomic_read(&lock->w_state);
     ethr_atomic_inc(&lock->w_state);
-
     eltd = lcnt_get_thread_data();
 
     ASSERT(eltd);
 
     if (w_state > 0) {
-	eltd->lock_in_conflict = 1;
-	/* only set the timer if nobody else has it
-	 * This should only happen when proc_locks aquires several locks
-	 * 'atomicly'. All other locks will block the thread if w_state > 0
-	 * i.e. locked.
-	 */
-	if (eltd->timer_set == 0) {
-	    lcnt_time(&eltd->timer);
-	}
-	eltd->timer_set++;
+        eltd->lock_in_conflict = 1;
+        /* only set the timer if nobody else has it
+         * This should only happen when proc_locks aquires several locks
+         * 'atomicly'. All other locks will block the thread if w_state > 0
+         * i.e. locked.
+         */
+        if (eltd->timer_set == 0) {
+            lcnt_time(&eltd->timer);
+        }
+        eltd->timer_set++;
     } else {
-	eltd->lock_in_conflict = 0;
+        eltd->lock_in_conflict = 0;
     }
 }
 
@@ -493,16 +490,19 @@ void erts_lcnt_lock(erts_lcnt_lock_t *lock) {
 void erts_lcnt_lock_unaquire(erts_lcnt_lock_t *lock) {
     /* should check if this thread was "waiting" */
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
 
     ethr_atomic_dec(&lock->w_state);
 }
 
-/* erts_lcnt_lock_post
- * used when we get a lock (i.e. directly after a lock operation)
+/*
+ * erts_lcnt_lock_post
+ *
+ * Used when we get a lock (i.e. directly after a lock operation)
  * if the timer was set then we had to wait for the lock
  * lock_post will calculate the wait time.
  */
+
 void erts_lcnt_lock_post(erts_lcnt_lock_t *lock) {
     erts_lcnt_lock_post_x(lock, (char*)str_undefined, 0);
 }
@@ -517,31 +517,31 @@ void erts_lcnt_lock_post_x(erts_lcnt_lock_t *lock, char *file, unsigned int line
 #endif
 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
-    
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
+
 #ifdef DEBUG
     if (!(lock->flag & (ERTS_LCNT_LT_RWMUTEX | ERTS_LCNT_LT_RWSPINLOCK))) {
-	flowstate = ethr_atomic_read(&lock->flowstate);
-	ASSERT(flowstate == 0);
-	ethr_atomic_inc(&lock->flowstate);
+        flowstate = ethr_atomic_read(&lock->flowstate);
+        ASSERT(flowstate == 0);
+        ethr_atomic_inc(&lock->flowstate);
     }
 #endif
-    
+
     eltd = lcnt_get_thread_data();
-    
+
     ASSERT(eltd);
 
     /* if lock was in conflict, time it */
     stats = lcnt_get_lock_stats(lock, file, line);
     if (eltd->timer_set) {
-	lcnt_time(&timer);
-	
-	lcnt_time_diff(&time_wait, &timer, &(eltd->timer));
-	lcnt_update_stats(stats, eltd->lock_in_conflict, &time_wait);
-	eltd->timer_set--;
-	ASSERT(eltd->timer_set >= 0);
+        lcnt_time(&timer);
+
+        lcnt_time_diff(&time_wait, &timer, &(eltd->timer));
+        lcnt_update_stats(stats, eltd->lock_in_conflict, &time_wait);
+        eltd->timer_set--;
+        ASSERT(eltd->timer_set >= 0);
     } else {
-	lcnt_update_stats(stats, eltd->lock_in_conflict, NULL);
+        lcnt_update_stats(stats, eltd->lock_in_conflict, NULL);
     }
 
 }
@@ -550,27 +550,28 @@ void erts_lcnt_lock_post_x(erts_lcnt_lock_t *lock, char *file, unsigned int line
 
 void erts_lcnt_unlock_opt(erts_lcnt_lock_t *lock, Uint16 option) {
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
     if (option & ERTS_LCNT_LO_WRITE) ethr_atomic_dec(&lock->w_state);
     if (option & ERTS_LCNT_LO_READ ) ethr_atomic_dec(&lock->r_state);
 }
 
 void erts_lcnt_unlock(erts_lcnt_lock_t *lock) {
-#ifdef DEBUG
-    erts_aint_t w_state;  
-    erts_aint_t flowstate;
-#endif
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
 #ifdef DEBUG
-    /* flowstate */
-    flowstate = ethr_atomic_read(&lock->flowstate);
-    ASSERT(flowstate == 1);
-    ethr_atomic_dec(&lock->flowstate);
-    
-    /* write state */
-    w_state = ethr_atomic_read(&lock->w_state);
-    ASSERT(w_state > 0);
+    {
+        erts_aint_t w_state;  
+        erts_aint_t flowstate;
+
+        /* flowstate */
+        flowstate = ethr_atomic_read(&lock->flowstate);
+        ASSERT(flowstate == 1);
+        ethr_atomic_dec(&lock->flowstate);
+
+        /* write state */
+        w_state = ethr_atomic_read(&lock->w_state);
+        ASSERT(w_state > 0);
+    }
 #endif
     ethr_atomic_dec(&lock->w_state);
 }
@@ -579,35 +580,34 @@ void erts_lcnt_unlock(erts_lcnt_lock_t *lock) {
 
 void erts_lcnt_trylock_opt(erts_lcnt_lock_t *lock, int res, Uint16 option) {
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
     /* Determine lock_state via res instead of state */
     if (res != EBUSY) {
-	if (option & ERTS_LCNT_LO_WRITE) ethr_atomic_inc(&lock->w_state);
-	if (option & ERTS_LCNT_LO_READ ) ethr_atomic_inc(&lock->r_state);
-	lcnt_update_stats(&(lock->stats[0]), 0, NULL);
+        if (option & ERTS_LCNT_LO_WRITE) ethr_atomic_inc(&lock->w_state);
+        if (option & ERTS_LCNT_LO_READ ) ethr_atomic_inc(&lock->r_state);
+        lcnt_update_stats(&(lock->stats[0]), 0, NULL);
     } else {
         ethr_atomic_inc(&lock->stats[0].tries);
         ethr_atomic_inc(&lock->stats[0].colls);
     }
 }
 
-   
+
 void erts_lcnt_trylock(erts_lcnt_lock_t *lock, int res) {
     /* Determine lock_state via res instead of state */
-#ifdef DEBUG
-    erts_aint_t flowstate;
-#endif 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
-    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+    if (ERTS_LCNT_IS_LOCK_INVALID(lock)) return;
     if (res != EBUSY) {
-	
 #ifdef DEBUG
-	flowstate = ethr_atomic_read(&lock->flowstate);
-	ASSERT(flowstate == 0);
-    	ethr_atomic_inc( &lock->flowstate);
+        {
+            erts_aint_t flowstate;
+            flowstate = ethr_atomic_read(&lock->flowstate);
+            ASSERT(flowstate == 0);
+            ethr_atomic_inc( &lock->flowstate);
+        }
 #endif
-	ethr_atomic_inc(&lock->w_state);
-	lcnt_update_stats(&(lock->stats[0]), 0, NULL);
+        ethr_atomic_inc(&lock->w_state);
+        lcnt_update_stats(&(lock->stats[0]), 0, NULL);
     } else {
         ethr_atomic_inc(&lock->stats[0].tries);
         ethr_atomic_inc(&lock->stats[0].colls);
@@ -662,13 +662,13 @@ void erts_lcnt_clear_counters(void) {
     lcnt_lock();
 
     list = erts_lcnt_data->current_locks;
-    
+
     for (lock = list->head; lock != NULL; lock = lock->next) {
-    	for( i = 0; i < ERTS_LCNT_MAX_LOCK_LOCATIONS; i++) {
-	    stats = &lock->stats[i];
-	    lcnt_clear_stats(stats);
-    	}
-	lock->n_stats = 1;
+        for( i = 0; i < ERTS_LCNT_MAX_LOCK_LOCATIONS; i++) {
+            stats = &lock->stats[i];
+            lcnt_clear_stats(stats);
+        }
+        lock->n_stats = 1;
     }
 
     /* empty deleted locks in lock list */
@@ -681,14 +681,14 @@ void erts_lcnt_clear_counters(void) {
 
 erts_lcnt_data_t *erts_lcnt_get_data(void) {
     erts_lcnt_time_t timer_stop;
-    
+
     lcnt_lock();
-    
+
     lcnt_time(&timer_stop);
     lcnt_time_diff(&(erts_lcnt_data->duration), &timer_stop, &timer_start);
-    
+
     lcnt_unlock();
-    
+
     return erts_lcnt_data;
 }
 
diff --git a/erts/emulator/beam/erl_lock_count.h b/erts/emulator/beam/erl_lock_count.h
index 09fadd7e9e..051f55271d 100644
--- a/erts/emulator/beam/erl_lock_count.h
+++ b/erts/emulator/beam/erl_lock_count.h
@@ -20,7 +20,7 @@
 /*
  * Description:	Statistics for locks.
  *
- * Author:	Bj�rn-Egil Dahlberg
+ * Author:	Björn-Egil Dahlberg
  * Date:	2008-07-03
  * Abstract:
  * 	Locks statistics internal representation.
@@ -95,30 +95,35 @@
 #define ERTS_LCNT_LO_WRITE      (((Uint16) 1) << 7)
 
 #define ERTS_LCNT_LO_READ_WRITE ( ERTS_LCNT_LO_READ  \
-				| ERTS_LCNT_LO_WRITE )
+                                | ERTS_LCNT_LO_WRITE )
 
 #define ERTS_LCNT_LT_ALL        ( ERTS_LCNT_LT_SPINLOCK   \
-				| ERTS_LCNT_LT_RWSPINLOCK \
-				| ERTS_LCNT_LT_MUTEX      \
-				| ERTS_LCNT_LT_RWMUTEX    \
-				| ERTS_LCNT_LT_PROCLOCK   )
+                                | ERTS_LCNT_LT_RWSPINLOCK \
+                                | ERTS_LCNT_LT_MUTEX      \
+                                | ERTS_LCNT_LT_RWMUTEX    \
+                                | ERTS_LCNT_LT_PROCLOCK   )
+
+#define ERTS_LCNT_LOCK_TYPE(lock)       ((lock)->flag & ERTS_LCNT_LT_ALL)
+#define ERTS_LCNT_IS_LOCK_INVALID(lock) (!((lock)->flag & ERTS_LCNT_LT_ALL))
+#define ERTS_LCNT_CLEAR_FLAG(lock)      ((lock)->flag = 0)
+
 /* runtime options */
 
-#define ERTS_LCNT_OPT_SUSPEND   (((Uint16) 1) << 0)
-#define ERTS_LCNT_OPT_LOCATION  (((Uint16) 1) << 1)
-#define ERTS_LCNT_OPT_PROCLOCK  (((Uint16) 1) << 2)
-#define ERTS_LCNT_OPT_COPYSAVE  (((Uint16) 1) << 3)
-#define ERTS_LCNT_OPT_PORTLOCK  (((Uint16) 1) << 4)
+#define ERTS_LCNT_OPT_SUSPEND  (((Uint16) 1) << 0)
+#define ERTS_LCNT_OPT_LOCATION (((Uint16) 1) << 1)
+#define ERTS_LCNT_OPT_PROCLOCK (((Uint16) 1) << 2)
+#define ERTS_LCNT_OPT_PORTLOCK (((Uint16) 1) << 3)
+#define ERTS_LCNT_OPT_COPYSAVE (((Uint16) 1) << 4)
 
 typedef struct {
     unsigned long s;
     unsigned long ns;
 } erts_lcnt_time_t;
-    
+
 extern erts_lcnt_time_t timer_start;
 
 typedef struct {
-   Uint32 ns[ERTS_LCNT_HISTOGRAM_SLOT_SIZE]; /* log2 array of nano seconds occurences */
+    Uint32 ns[ERTS_LCNT_HISTOGRAM_SLOT_SIZE]; /* log2 array of nano seconds occurences */
 } erts_lcnt_hist_t;
 
 typedef struct erts_lcnt_lock_stats_s {
@@ -129,10 +134,10 @@ typedef struct erts_lcnt_lock_stats_s {
 
     char         *file;       /* which file the lock was taken */
     unsigned int  line;       /* line number in file */
-    
+
     ethr_atomic_t tries;      /* n tries to get lock */
     ethr_atomic_t colls;      /* n collisions of tries to get lock */
-    
+
     unsigned long timer_n;    /* #times waited for lock */
     erts_lcnt_time_t timer;   /* total wait time for lock */
     erts_lcnt_hist_t hist;
@@ -155,7 +160,7 @@ typedef struct erts_lcnt_lock_s {
     /* statistics */
     unsigned int n_stats;
     erts_lcnt_lock_stats_t stats[ERTS_LCNT_MAX_LOCK_LOCATIONS]; /* first entry is "undefined"*/
-    
+
     /* chains for list handling  */
     /* data is hold by lcnt_lock */
     struct erts_lcnt_lock_s *prev;
@@ -167,7 +172,7 @@ typedef struct {
     erts_lcnt_lock_t *tail;
     unsigned long n;
 } erts_lcnt_lock_list_t;
-    
+
 typedef struct {
     erts_lcnt_time_t duration;			/* time since last clear */
     erts_lcnt_lock_list_t *current_locks;
@@ -205,6 +210,7 @@ void erts_lcnt_list_delete(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock);
 /* lock operations (global) */
 void erts_lcnt_init_lock(erts_lcnt_lock_t *lock, char *name, Uint16 flag);
 void erts_lcnt_init_lock_x(erts_lcnt_lock_t *lock, char *name, Uint16 flag, Eterm id);
+void erts_lcnt_init_lock_empty(erts_lcnt_lock_t *lock);
 void erts_lcnt_destroy_lock(erts_lcnt_lock_t *lock);
 
 void erts_lcnt_lock(erts_lcnt_lock_t *lock);
@@ -226,7 +232,5 @@ void   erts_lcnt_clear_counters(void);
 char  *erts_lcnt_lock_type(Uint16 type);
 erts_lcnt_data_t *erts_lcnt_get_data(void);
 
-#define ERTS_LCNT_LOCK_TYPE(lockp)	((lockp)->flag & ERTS_LCNT_LT_ALL)
-
 #endif /* ifdef  ERTS_ENABLE_LOCK_COUNT  */
 #endif /* ifndef ERTS_LOCK_COUNT_H__     */
diff --git a/erts/emulator/beam/erl_process_lock.c b/erts/emulator/beam/erl_process_lock.c
index b28bc498f6..0548c6137c 100644
--- a/erts/emulator/beam/erl_process_lock.c
+++ b/erts/emulator/beam/erl_process_lock.c
@@ -110,6 +110,9 @@ static struct {
 
 erts_pix_lock_t erts_pix_locks[ERTS_NO_OF_PIX_LOCKS];
 
+#ifdef ERTS_ENABLE_LOCK_COUNT
+static void lcnt_enable_proc_lock_count(Process *proc, int enable);
+#endif
 
 void
 erts_init_proc_lock(int cpus)
@@ -1083,30 +1086,32 @@ erts_proc_lock_fin(Process *p)
 /* --- Process lock counting ----------------------------------------------- */
 
 #if ERTS_PROC_LOCK_OWN_IMPL && defined(ERTS_ENABLE_LOCK_COUNT)
-void erts_lcnt_proc_lock_init(Process *p) {
-    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) {
-    if (p->common.id != ERTS_INVALID_PID) {
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_main),   "proc_main",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_msgq),   "proc_msgq",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_btm),    "proc_btm",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_link),   "proc_link",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_status), "proc_status", ERTS_LCNT_LT_PROCLOCK, p->common.id);
-    } else {
-	erts_lcnt_init_lock(&(p->lock.lcnt_main),   "proc_main",   ERTS_LCNT_LT_PROCLOCK);
-	erts_lcnt_init_lock(&(p->lock.lcnt_msgq),   "proc_msgq",   ERTS_LCNT_LT_PROCLOCK);
-	erts_lcnt_init_lock(&(p->lock.lcnt_btm),    "proc_btm",   ERTS_LCNT_LT_PROCLOCK);
-	erts_lcnt_init_lock(&(p->lock.lcnt_link),   "proc_link",   ERTS_LCNT_LT_PROCLOCK);
-	erts_lcnt_init_lock(&(p->lock.lcnt_status), "proc_status", ERTS_LCNT_LT_PROCLOCK);
-    }
-    } else {
-	sys_memzero(&(p->lock.lcnt_main), sizeof(p->lock.lcnt_main));
-	sys_memzero(&(p->lock.lcnt_msgq), sizeof(p->lock.lcnt_msgq));
-	sys_memzero(&(p->lock.lcnt_btm), sizeof(p->lock.lcnt_btm));
-	sys_memzero(&(p->lock.lcnt_link), sizeof(p->lock.lcnt_link));
-	sys_memzero(&(p->lock.lcnt_status), sizeof(p->lock.lcnt_status));
-    }
+
+void erts_lcnt_enable_proc_lock_count(int enable) {
+    int ix, max = erts_ptab_max(&erts_proc);
+    Process *proc = NULL;
+    for (ix = 0; ix < max; ++ix) {
+	if ((proc = erts_pix2proc(ix)) != NULL)
+            lcnt_enable_proc_lock_count(proc, enable);
+    } /* for all processes */
 }
-	
+
+void erts_lcnt_proc_lock_init(Process *p) {
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK)) {
+        erts_lcnt_init_lock_empty(&(p->lock.lcnt_main));
+        erts_lcnt_init_lock_empty(&(p->lock.lcnt_msgq));
+        erts_lcnt_init_lock_empty(&(p->lock.lcnt_btm));
+        erts_lcnt_init_lock_empty(&(p->lock.lcnt_link));
+        erts_lcnt_init_lock_empty(&(p->lock.lcnt_status));
+    } else { /* now the common case */
+        Eterm pid = (p->common.id != ERTS_INVALID_PID) ? p->common.id : NIL;
+        erts_lcnt_init_lock_x(&(p->lock.lcnt_main),  "proc_main",  ERTS_LCNT_LT_PROCLOCK, pid);
+        erts_lcnt_init_lock_x(&(p->lock.lcnt_msgq),  "proc_msgq",  ERTS_LCNT_LT_PROCLOCK, pid);
+        erts_lcnt_init_lock_x(&(p->lock.lcnt_btm),   "proc_btm",   ERTS_LCNT_LT_PROCLOCK, pid);
+        erts_lcnt_init_lock_x(&(p->lock.lcnt_link),  "proc_link",  ERTS_LCNT_LT_PROCLOCK, pid);
+        erts_lcnt_init_lock_x(&(p->lock.lcnt_status),"proc_status",ERTS_LCNT_LT_PROCLOCK, pid);
+    } /* the lock names should really be aligned to four characters */
+} /* logic reversed */
 
 void erts_lcnt_proc_lock_destroy(Process *p) {
     erts_lcnt_destroy_lock(&(p->lock.lcnt_main));
@@ -1116,28 +1121,31 @@ void erts_lcnt_proc_lock_destroy(Process *p) {
     erts_lcnt_destroy_lock(&(p->lock.lcnt_status));
 }
 
-void erts_lcnt_proc_lock(erts_proc_lock_t *lock, ErtsProcLocks locks) {
-    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) { 
-    if (locks & ERTS_PROC_LOCK_MAIN) {
-	erts_lcnt_lock(&(lock->lcnt_main));
-    }
-    if (locks & ERTS_PROC_LOCK_MSGQ) {
-        erts_lcnt_lock(&(lock->lcnt_msgq));
-    }
-    if (locks & ERTS_PROC_LOCK_BTM) {
-        erts_lcnt_lock(&(lock->lcnt_btm));
-    }
-    if (locks & ERTS_PROC_LOCK_LINK) {
-	erts_lcnt_lock(&(lock->lcnt_link));
-    }
-    if (locks & ERTS_PROC_LOCK_STATUS) {
-	erts_lcnt_lock(&(lock->lcnt_status));
+static void lcnt_enable_proc_lock_count(Process *proc, int enable) {
+    if (enable) {
+        if (!ERTS_LCNT_LOCK_TYPE(&(proc->lock.lcnt_main))) {
+            erts_lcnt_proc_lock_init(proc);
+        }
     }
+    else {
+        if (ERTS_LCNT_LOCK_TYPE(&(proc->lock.lcnt_main))) {
+            erts_lcnt_proc_lock_destroy(proc);
+        }
     }
 }
 
-void erts_lcnt_proc_lock_post_x(erts_proc_lock_t *lock, ErtsProcLocks locks, char *file, unsigned int line) {
-    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) { 
+void erts_lcnt_proc_lock(erts_proc_lock_t *lock, ErtsProcLocks locks) {
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK)) return;
+    if (locks & ERTS_PROC_LOCK_MAIN) { erts_lcnt_lock(&(lock->lcnt_main)); }
+    if (locks & ERTS_PROC_LOCK_MSGQ) { erts_lcnt_lock(&(lock->lcnt_msgq)); }
+    if (locks & ERTS_PROC_LOCK_BTM) { erts_lcnt_lock(&(lock->lcnt_btm)); }
+    if (locks & ERTS_PROC_LOCK_LINK) { erts_lcnt_lock(&(lock->lcnt_link)); }
+    if (locks & ERTS_PROC_LOCK_STATUS) { erts_lcnt_lock(&(lock->lcnt_status)); }
+}
+
+void erts_lcnt_proc_lock_post_x(erts_proc_lock_t *lock, ErtsProcLocks locks,
+                                char *file, unsigned int line) {
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK)) return;
     if (locks & ERTS_PROC_LOCK_MAIN) {
 	erts_lcnt_lock_post_x(&(lock->lcnt_main), file, line);
     }
@@ -1153,90 +1161,34 @@ void erts_lcnt_proc_lock_post_x(erts_proc_lock_t *lock, ErtsProcLocks locks, cha
     if (locks & ERTS_PROC_LOCK_STATUS) {
 	erts_lcnt_lock_post_x(&(lock->lcnt_status), file, line);
     }
-    }
 }
 
 void erts_lcnt_proc_lock_unaquire(erts_proc_lock_t *lock, ErtsProcLocks locks) {
-    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) { 
-    if (locks & ERTS_PROC_LOCK_MAIN) {
-	erts_lcnt_lock_unaquire(&(lock->lcnt_main));
-    }
-    if (locks & ERTS_PROC_LOCK_MSGQ) {
-        erts_lcnt_lock_unaquire(&(lock->lcnt_msgq));
-    }
-    if (locks & ERTS_PROC_LOCK_BTM) {
-        erts_lcnt_lock_unaquire(&(lock->lcnt_btm));
-    }
-    if (locks & ERTS_PROC_LOCK_LINK) {
-	erts_lcnt_lock_unaquire(&(lock->lcnt_link));
-    }
-    if (locks & ERTS_PROC_LOCK_STATUS) {
-	erts_lcnt_lock_unaquire(&(lock->lcnt_status));
-    }
-    }
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK)) return;
+    if (locks & ERTS_PROC_LOCK_MAIN) { erts_lcnt_lock_unaquire(&(lock->lcnt_main)); }
+    if (locks & ERTS_PROC_LOCK_MSGQ) { erts_lcnt_lock_unaquire(&(lock->lcnt_msgq)); }
+    if (locks & ERTS_PROC_LOCK_BTM) { erts_lcnt_lock_unaquire(&(lock->lcnt_btm)); }
+    if (locks & ERTS_PROC_LOCK_LINK) { erts_lcnt_lock_unaquire(&(lock->lcnt_link)); }
+    if (locks & ERTS_PROC_LOCK_STATUS) { erts_lcnt_lock_unaquire(&(lock->lcnt_status)); }
 }
 
 void erts_lcnt_proc_unlock(erts_proc_lock_t *lock, ErtsProcLocks locks) {
-    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) { 
-    if (locks & ERTS_PROC_LOCK_MAIN) {
-	erts_lcnt_unlock(&(lock->lcnt_main));
-    }
-    if (locks & ERTS_PROC_LOCK_MSGQ) {
-        erts_lcnt_unlock(&(lock->lcnt_msgq));
-    }
-    if (locks & ERTS_PROC_LOCK_BTM) {
-        erts_lcnt_unlock(&(lock->lcnt_btm));
-    }
-    if (locks & ERTS_PROC_LOCK_LINK) {
-	erts_lcnt_unlock(&(lock->lcnt_link));
-    }
-    if (locks & ERTS_PROC_LOCK_STATUS) {
-	erts_lcnt_unlock(&(lock->lcnt_status));
-    }
-    }
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK)) return;
+    if (locks & ERTS_PROC_LOCK_MAIN) { erts_lcnt_unlock(&(lock->lcnt_main)); }
+    if (locks & ERTS_PROC_LOCK_MSGQ) { erts_lcnt_unlock(&(lock->lcnt_msgq)); }
+    if (locks & ERTS_PROC_LOCK_BTM) { erts_lcnt_unlock(&(lock->lcnt_btm)); }
+    if (locks & ERTS_PROC_LOCK_LINK) { erts_lcnt_unlock(&(lock->lcnt_link)); }
+    if (locks & ERTS_PROC_LOCK_STATUS) { erts_lcnt_unlock(&(lock->lcnt_status)); }
 }
 void erts_lcnt_proc_trylock(erts_proc_lock_t *lock, ErtsProcLocks locks, int res) {
-    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) { 
-    if (locks & ERTS_PROC_LOCK_MAIN) {
-	erts_lcnt_trylock(&(lock->lcnt_main), res);
-    }
-    if (locks & ERTS_PROC_LOCK_MSGQ) {
-        erts_lcnt_trylock(&(lock->lcnt_msgq), res);
-    }
-    if (locks & ERTS_PROC_LOCK_BTM) {
-        erts_lcnt_trylock(&(lock->lcnt_btm), res);
-    }
-    if (locks & ERTS_PROC_LOCK_LINK) {
-	erts_lcnt_trylock(&(lock->lcnt_link), res);
-    }
-    if (locks & ERTS_PROC_LOCK_STATUS) {
-	erts_lcnt_trylock(&(lock->lcnt_status), res);
-    }
-    }
-}
-
-
-void erts_lcnt_enable_proc_lock_count(int enable)
-{
-    int i, max = erts_ptab_max(&erts_proc);
-
-    for (i = 0; i < max; ++i) {
-	Process* p = erts_pix2proc(i);
-	if (p) {
-	    if (enable) {
-		if (!ERTS_LCNT_LOCK_TYPE(&(p->lock.lcnt_main))) {
-		    erts_lcnt_proc_lock_init(p);
-		}
-	    } else {
-		if (ERTS_LCNT_LOCK_TYPE(&(p->lock.lcnt_main))) {
-		    erts_lcnt_proc_lock_destroy(p);
-		}
-	    }
-	}
-    }
-}
-
-#endif /* ifdef ERTS_ENABLE_LOCK_COUNT */
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK)) return;
+    if (locks & ERTS_PROC_LOCK_MAIN) { erts_lcnt_trylock(&(lock->lcnt_main), res); }
+    if (locks & ERTS_PROC_LOCK_MSGQ) { erts_lcnt_trylock(&(lock->lcnt_msgq), res); }
+    if (locks & ERTS_PROC_LOCK_BTM) { erts_lcnt_trylock(&(lock->lcnt_btm), res); }
+    if (locks & ERTS_PROC_LOCK_LINK) { erts_lcnt_trylock(&(lock->lcnt_link), res); }
+    if (locks & ERTS_PROC_LOCK_STATUS) { erts_lcnt_trylock(&(lock->lcnt_status), res); }
+} /* reversed logic */
+#endif /* ERTS_ENABLE_LOCK_COUNT */
 
 
 /* --- Process lock checking ----------------------------------------------- */
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 23f208c2eb..42f0bc88f2 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -1534,12 +1534,10 @@ erts_schedule_proc2port_signal(Process *c_p,
 }
 
 static ERTS_INLINE void
-send_badsig(Port *prt)
-{
+send_badsig(Port *prt) {
     ErtsProcLocks rp_locks = ERTS_PROC_LOCKS_XSIG_SEND;
     Process* rp;
     Eterm connected = ERTS_PORT_GET_CONNECTED(prt);
-
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     ERTS_LC_ASSERT(erts_get_scheduler_id());
 
@@ -1559,15 +1557,13 @@ send_badsig(Port *prt)
 					 0);
 	if (rp_locks)
 	    erts_smp_proc_unlock(rp, rp_locks);
-    }
-}
+    } /* exit sent */
+} /* send_badsig */
 
 static void
-badsig_received(int bang_op,
-		Port *prt,
+badsig_received(int bang_op, Port *prt,
 		erts_aint32_t state,
-		int bad_output_value)
-{
+		int bad_output_value) {
     /*
      * if (bang_op)
      *   we are part of a "Prt ! Something" operation
@@ -1583,12 +1579,12 @@ badsig_received(int bang_op,
 	}
 	if (bang_op)
 	    send_badsig(prt);
-    }
-}
+    } /* not invalid */
+} /* behaved accordingly */
 
 static int
-port_badsig(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
-{
+port_badsig(Port *prt, erts_aint32_t state, int op,
+            ErtsProc2PortSigData *sigdp) {
     if (op == ERTS_PROC2PORT_SIG_EXEC)
 	badsig_received(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BANG_OP,
 			prt,
@@ -1597,16 +1593,14 @@ port_badsig(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
     if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
 	port_sched_op_reply(sigdp->caller, sigdp->ref, am_badarg);
     return ERTS_PORT_REDS_BADSIG;
-}
-
-
-/*
- * bad_port_signal() will
+} /* port_badsig */
+/* bad_port_signal() will
  * - preserve signal order of signals.
  * - send a 'badsig' exit signal to connected process if 'from' is an
  *   internal pid and the port is alive when the bad signal reaches
  *   it.
  */
+
 static ErtsPortOpResult
 bad_port_signal(Process *c_p,
 		int flags,
@@ -2804,7 +2798,6 @@ void erts_init_io(int port_tab_size,
 }
 
 #if defined(ERTS_ENABLE_LOCK_COUNT) && defined(ERTS_SMP)
-
 static ERTS_INLINE void lcnt_enable_drv_lock_count(erts_driver_t *dp, int enable)
 {
     if (dp->lock) {
@@ -2844,25 +2837,26 @@ static ERTS_INLINE void lcnt_enable_port_lock_count(Port *prt, int enable)
     }
 }
 
-void erts_lcnt_enable_io_lock_count(int enable)
-{
+void erts_lcnt_enable_io_lock_count(int enable) {
     erts_driver_t *dp;
-    int i, max = erts_ptab_max(&erts_port);
+    int ix, max = erts_ptab_max(&erts_port);
+    Port *prt;
 
-    for (i = 0; i < max; i++) {
-	Port *prt = erts_pix2port(i);
-	if (prt)
+    for (ix = 0; ix < max; ix++) {
+	if ((prt = erts_pix2port(ix)) != NULL) {
 	    lcnt_enable_port_lock_count(prt, enable);
-    }
+        }
+    } /* for all ports */
 
     lcnt_enable_drv_lock_count(&vanilla_driver, enable);
     lcnt_enable_drv_lock_count(&spawn_driver, enable);
     lcnt_enable_drv_lock_count(&fd_driver, enable);
-    for (dp = driver_list; dp; dp = dp->next)
+    /* enable lock counting in all drivers */
+    for (dp = driver_list; dp; dp = dp->next) {
 	lcnt_enable_drv_lock_count(dp, enable);
-}
-#endif
-
+    }
+} /* enable/disable lock counting of ports */
+#endif /* defined(ERTS_ENABLE_LOCK_COUNT) && defined(ERTS_SMP) */
 /*
  * Buffering of data when using line oriented I/O on ports
  */