From 664ed2a6fd2b324bb6b56db3d3eca853cfda8f61 Mon Sep 17 00:00:00 2001 From: Lukas Larsson Date: Fri, 12 Sep 2014 16:38:00 +0200 Subject: 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 --- erts/emulator/beam/erl_threads.h | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) (limited to 'erts/emulator/beam/erl_threads.h') 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 -- cgit v1.2.3