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authorSverker Eriksson <[email protected]>2016-02-24 17:55:04 +0100
committerSverker Eriksson <[email protected]>2016-02-24 17:55:04 +0100
commit03743cd4193a2ca97f9b9a52a25e63f616e8fc07 (patch)
tree9c1f4094a2105ec4bf19dd0d16e76b598d0e608d /erts/emulator/beam/erl_msacc.c
parent1b094d72ffc56069c72f17c7edd673dbbfe47e39 (diff)
parent35739bd06776f90526006486b3f4ab7e54f7f951 (diff)
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Merge branch 'master' into sverk/master/halt-INT_MIN
Diffstat (limited to 'erts/emulator/beam/erl_msacc.c')
-rw-r--r--erts/emulator/beam/erl_msacc.c486
1 files changed, 486 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_msacc.c b/erts/emulator/beam/erl_msacc.c
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+/*
+ * %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
+}