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, 27 insertions, 7 deletions

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