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Diffstat (limited to 'erts/emulator/beam/erl_msacc.c')
| -rw-r--r-- | erts/emulator/beam/erl_msacc.c | 486 |
1 files changed, 486 insertions, 0 deletions
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 +} |