erts: Add microstate accounting

Microstate accounting is a way to track which state the
different threads within ERTS are in. The main usage area
is to pin point performance bottlenecks by checking which
states the threads are in and then from there figuring out
why and where to optimize.

Since checking whether microstate accounting is on or off is
relatively expensive if done in a short loop only a few of the
states are enabled by default and more states can be enabled
through configure.

I've done some benchmarking and the overhead with it turned off
is not noticible and with it on it is a fraction of a percent.
If you enable the extra states, depending on the benchmark,
the ovehead when turned off is about 1% and when turned on
somewhere inbetween 5-15%.

OTP-12345

1 files changed, 28 insertions, 6 deletions

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);