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authorRickard Green <[email protected]>2011-05-13 14:27:41 +0200
committerRickard Green <[email protected]>2011-05-13 14:27:41 +0200
commit0c73cf3d305c4b033c6e1efa6ebd08796a1d8682 (patch)
tree4aa3a5a40d8303f1f6f01cd90cee43857371db07 /erts/emulator/beam/erl_process.c
parent926795501b71ebf9ca4b22927021fa551549f9b0 (diff)
parent139fa05489a6ba3e4384e6f20ea3f943741449d5 (diff)
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Merge branch 'rickard/barriers/OTP-9281' into dev
* rickard/barriers/OTP-9281: Silence warnings Fix build with hipe on amd64 Reduce number of atomic ops Use 32-bit atomic for port snapshot Remove pointless erts_ports_alive variable Ensure quick break Ensure that all rehashing information are seen when done Ensure that stack updates are seen when stack is released Add needed barriers for write_concurrency tables Homogenize memory barriers on atomics
Diffstat (limited to 'erts/emulator/beam/erl_process.c')
-rw-r--r--erts/emulator/beam/erl_process.c135
1 files changed, 100 insertions, 35 deletions
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 05172aaefa..2704359a8f 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -166,9 +166,8 @@ static struct {
static struct {
erts_smp_mtx_t update_mtx;
- erts_smp_atomic32_t active_runqs;
+ erts_smp_atomic32_t no_runqs;
int last_active_runqs;
- erts_smp_atomic32_t used_runqs;
int forced_check_balance;
erts_smp_atomic32_t checking_balance;
int halftime;
@@ -965,7 +964,7 @@ sched_spin_wait(ErtsSchedulerSleepInfo *ssi, int spincount)
erts_aint32_t flgs;
do {
- flgs = erts_smp_atomic32_read(&ssi->flags);
+ flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
if ((flgs & (ERTS_SSI_FLG_SLEEPING|ERTS_SSI_FLG_WAITING))
!= (ERTS_SSI_FLG_SLEEPING|ERTS_SSI_FLG_WAITING)) {
break;
@@ -1114,7 +1113,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
else {
erts_aint_t dt;
- erts_smp_atomic32_set(&function_calls, 0);
+ erts_smp_atomic32_set_relb(&function_calls, 0);
*fcalls = 0;
sched_waiting_sys(esdp->no, rq);
@@ -1147,7 +1146,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
nonblockable_aux_work(esdp, ssi, aux_work);
#endif
- flgs = erts_smp_atomic32_read(&ssi->flags);
+ flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
if (!(flgs & ERTS_SSI_FLG_WAITING)) {
ASSERT(!(flgs & ERTS_SSI_FLG_SLEEPING));
goto sys_woken;
@@ -1333,6 +1332,76 @@ wake_all_schedulers(void)
}
}
+#define ERTS_NO_USED_RUNQS_SHIFT 16
+#define ERTS_NO_RUNQS_MASK 0xffff
+
+#if ERTS_MAX_NO_OF_SCHEDULERS > ERTS_NO_RUNQS_MASK
+# error "Too large amount of schedulers allowed"
+#endif
+
+static ERTS_INLINE void
+init_no_runqs(int active, int used)
+{
+ erts_aint32_t no_runqs = (erts_aint32_t) (active & ERTS_NO_RUNQS_MASK);
+ no_runqs |= (erts_aint32_t) ((used & ERTS_NO_RUNQS_MASK) << ERTS_NO_USED_RUNQS_SHIFT);
+ erts_smp_atomic32_init(&balance_info.no_runqs, no_runqs);
+}
+
+static ERTS_INLINE void
+get_no_runqs(int *active, int *used)
+{
+ erts_aint32_t no_runqs = erts_smp_atomic32_read(&balance_info.no_runqs);
+ if (active)
+ *active = (int) (no_runqs & ERTS_NO_RUNQS_MASK);
+ if (used)
+ *used = (int) ((no_runqs >> ERTS_NO_USED_RUNQS_SHIFT) & ERTS_NO_RUNQS_MASK);
+}
+
+static ERTS_INLINE void
+set_no_used_runqs(int used)
+{
+ erts_aint32_t exp = erts_smp_atomic32_read(&balance_info.no_runqs);
+ while (1) {
+ erts_aint32_t act, new;
+ new = (used << ERTS_NO_USED_RUNQS_SHIFT) | (exp & ERTS_NO_RUNQS_MASK);
+ act = erts_smp_atomic32_cmpxchg(&balance_info.no_runqs, new, exp);
+ if (act == exp)
+ break;
+ exp = act;
+ }
+}
+
+static ERTS_INLINE void
+set_no_active_runqs(int active)
+{
+ erts_aint32_t exp = erts_smp_atomic32_read(&balance_info.no_runqs);
+ while (1) {
+ erts_aint32_t act, new;
+ new = (exp & (ERTS_NO_RUNQS_MASK << ERTS_NO_USED_RUNQS_SHIFT)) | active;
+ act = erts_smp_atomic32_cmpxchg(&balance_info.no_runqs, new, exp);
+ if (act == exp)
+ break;
+ exp = act;
+ }
+}
+
+static ERTS_INLINE int
+try_inc_no_active_runqs(int active)
+{
+ erts_aint32_t exp = erts_smp_atomic32_read(&balance_info.no_runqs);
+ if (((exp >> ERTS_NO_USED_RUNQS_SHIFT) & ERTS_NO_RUNQS_MASK) < active)
+ return 0;
+ if ((exp & ERTS_NO_RUNQS_MASK) + 1 == active) {
+ erts_aint32_t new, act;
+ new = (exp & ~ERTS_NO_RUNQS_MASK) | active;
+ act = erts_smp_atomic32_cmpxchg(&balance_info.no_runqs, new, exp);
+ if (act == exp)
+ return 1;
+ }
+ return 0;
+}
+
+
static ERTS_INLINE int
chk_wake_sched(ErtsRunQueue *crq, int ix, int activate)
{
@@ -1344,9 +1413,7 @@ chk_wake_sched(ErtsRunQueue *crq, int ix, int activate)
iflgs = erts_smp_atomic32_read(&wrq->info_flags);
if (!(iflgs & (ERTS_RUNQ_IFLG_SUSPENDED|ERTS_RUNQ_IFLG_NONEMPTY))) {
if (activate) {
- if (ix == erts_smp_atomic32_cmpxchg(&balance_info.active_runqs,
- ix+1,
- ix)) {
+ if (try_inc_no_active_runqs(ix+1)) {
erts_smp_xrunq_lock(crq, wrq);
wrq->flags &= ~ERTS_RUNQ_FLG_INACTIVE;
erts_smp_xrunq_unlock(crq, wrq);
@@ -1363,8 +1430,9 @@ wake_scheduler_on_empty_runq(ErtsRunQueue *crq)
{
int ix = crq->ix;
int stop_ix = ix;
- int active_ix = erts_smp_atomic32_read(&balance_info.active_runqs);
- int balance_ix = erts_smp_atomic32_read(&balance_info.used_runqs);
+ int active_ix, balance_ix;
+
+ get_no_runqs(&active_ix, &balance_ix);
if (active_ix > balance_ix)
active_ix = balance_ix;
@@ -1416,7 +1484,7 @@ erts_sched_notify_check_cpu_bind(void)
int ix;
if (erts_common_run_queue) {
for (ix = 0; ix < erts_no_schedulers; ix++)
- erts_smp_atomic32_set(&ERTS_SCHEDULER_IX(ix)->chk_cpu_bind, 1);
+ erts_smp_atomic32_set_relb(&ERTS_SCHEDULER_IX(ix)->chk_cpu_bind, 1);
wake_all_schedulers();
}
else {
@@ -1871,8 +1939,7 @@ try_steal_task(ErtsRunQueue *rq)
ERTS_SMP_LC_CHK_RUNQ_LOCK(rq, rq_locked);
- active_rqs = erts_smp_atomic32_read(&balance_info.active_runqs);
- blnc_rqs = erts_smp_atomic32_read(&balance_info.used_runqs);
+ get_no_runqs(&active_rqs, &blnc_rqs);
if (active_rqs > blnc_rqs)
active_rqs = blnc_rqs;
@@ -1883,7 +1950,7 @@ try_steal_task(ErtsRunQueue *rq)
if (active_rqs < blnc_rqs) {
int no = blnc_rqs - active_rqs;
int stop_ix = vix = active_rqs + rq->ix % no;
- while (erts_smp_atomic32_read(&no_empty_run_queues) < blnc_rqs) {
+ while (erts_smp_atomic32_read_acqb(&no_empty_run_queues) < blnc_rqs) {
res = check_possible_steal_victim(rq, &rq_locked, vix);
if (res)
goto done;
@@ -1898,7 +1965,7 @@ try_steal_task(ErtsRunQueue *rq)
vix = rq->ix;
/* ... then try to steal a job from another active queue... */
- while (erts_smp_atomic32_read(&no_empty_run_queues) < blnc_rqs) {
+ while (erts_smp_atomic32_read_acqb(&no_empty_run_queues) < blnc_rqs) {
vix++;
if (vix >= active_rqs)
vix = 0;
@@ -1999,7 +2066,7 @@ check_balance(ErtsRunQueue *c_rq)
return;
}
- blnc_no_rqs = (int) erts_smp_atomic32_read(&balance_info.used_runqs);
+ get_no_runqs(NULL, &blnc_no_rqs);
if (blnc_no_rqs == 1) {
c_rq->check_balance_reds = INT_MAX;
erts_smp_atomic32_set(&balance_info.checking_balance, 0);
@@ -2038,7 +2105,8 @@ check_balance(ErtsRunQueue *c_rq)
forced = balance_info.forced_check_balance;
balance_info.forced_check_balance = 0;
- blnc_no_rqs = (int) erts_smp_atomic32_read(&balance_info.used_runqs);
+ get_no_runqs(&current_active, &blnc_no_rqs);
+
if (blnc_no_rqs == 1) {
erts_smp_mtx_unlock(&balance_info.update_mtx);
erts_smp_runq_lock(c_rq);
@@ -2052,8 +2120,6 @@ check_balance(ErtsRunQueue *c_rq)
if (balance_info.full_reds_history_index >= ERTS_FULL_REDS_HISTORY_SIZE)
balance_info.full_reds_history_index = 0;
- current_active = erts_smp_atomic32_read(&balance_info.active_runqs);
-
/* Read balance information for all run queues */
for (qix = 0; qix < blnc_no_rqs; qix++) {
ErtsRunQueue *rq = ERTS_RUNQ_IX(qix);
@@ -2387,7 +2453,7 @@ erts_fprintf(stderr, "--------------------------------\n");
}
balance_info.last_active_runqs = active;
- erts_smp_atomic32_set(&balance_info.active_runqs, active);
+ set_no_active_runqs(active);
balance_info.halftime = 1;
erts_smp_atomic32_set(&balance_info.checking_balance, 0);
@@ -2695,9 +2761,8 @@ erts_init_scheduling(int mrq, int no_schedulers, int no_schedulers_online)
erts_smp_atomic32_init(&schdlr_sspnd.msb.ongoing, 0);
erts_smp_atomic32_init(&schdlr_sspnd.active, no_schedulers);
schdlr_sspnd.msb.procs = NULL;
- erts_smp_atomic32_set(&balance_info.used_runqs,
- erts_common_run_queue ? 1 : no_schedulers_online);
- erts_smp_atomic32_init(&balance_info.active_runqs, no_schedulers);
+ init_no_runqs(no_schedulers,
+ erts_common_run_queue ? 1 : no_schedulers_online);
balance_info.last_active_runqs = no_schedulers;
erts_smp_mtx_init(&balance_info.update_mtx, "migration_info_update");
balance_info.forced_check_balance = 0;
@@ -2939,7 +3004,7 @@ sched_spin_suspended(ErtsSchedulerSleepInfo *ssi, int spincount)
erts_aint32_t flgs;
do {
- flgs = erts_smp_atomic32_read(&ssi->flags);
+ flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
if ((flgs & (ERTS_SSI_FLG_SLEEPING
| ERTS_SSI_FLG_WAITING
| ERTS_SSI_FLG_SUSPENDED))
@@ -3068,7 +3133,7 @@ suspend_scheduler(ErtsSchedulerData *esdp)
wake = 0;
}
- flgs = erts_smp_atomic32_read(&ssi->flags);
+ flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
if (!(flgs & ERTS_SSI_FLG_SUSPENDED))
break;
erts_smp_mtx_unlock(&schdlr_sspnd.mtx);
@@ -3292,7 +3357,7 @@ erts_set_schedulers_online(Process *p,
ErtsRunQueue *to_rq = ERTS_RUNQ_IX(ix % no);
evacuate_run_queue(from_rq, to_rq);
}
- erts_smp_atomic32_set(&balance_info.used_runqs, no);
+ set_no_used_runqs(no);
erts_smp_mtx_unlock(&balance_info.update_mtx);
erts_smp_mtx_lock(&schdlr_sspnd.mtx);
}
@@ -3346,7 +3411,7 @@ erts_set_schedulers_online(Process *p,
for (ix = erts_no_run_queues-1; ix >= no; ix--)
evacuate_run_queue(ERTS_RUNQ_IX(ix),
ERTS_RUNQ_IX(ix % no));
- erts_smp_atomic32_set(&balance_info.used_runqs, no);
+ set_no_used_runqs(no);
erts_smp_mtx_unlock(&balance_info.update_mtx);
erts_smp_mtx_lock(&schdlr_sspnd.mtx);
for (ix = no; ix < online; ix++) {
@@ -3443,7 +3508,7 @@ erts_block_multi_scheduling(Process *p, ErtsProcLocks plocks, int on, int all)
else {
erts_smp_mtx_unlock(&schdlr_sspnd.mtx);
erts_smp_mtx_lock(&balance_info.update_mtx);
- erts_smp_atomic32_set(&balance_info.used_runqs, 1);
+ set_no_used_runqs(1);
for (ix = 0; ix < online; ix++) {
ErtsRunQueue *rq = ERTS_RUNQ_IX(ix);
erts_smp_runq_lock(rq);
@@ -3580,7 +3645,7 @@ erts_block_multi_scheduling(Process *p, ErtsProcLocks plocks, int on, int all)
evacuate_run_queue(ERTS_RUNQ_IX(ix),
ERTS_RUNQ_IX(ix % online));
- erts_smp_atomic32_set(&balance_info.used_runqs, online);
+ set_no_used_runqs(online);
/* Make sure that we balance soon... */
balance_info.forced_check_balance = 1;
erts_smp_runq_lock(ERTS_RUNQ_IX(0));
@@ -5131,7 +5196,7 @@ Process *schedule(Process *p, int calls)
esdp = erts_get_scheduler_data();
rq = erts_get_runq_current(esdp);
ASSERT(esdp);
- fcalls = (int) erts_smp_atomic32_read(&function_calls);
+ fcalls = (int) erts_smp_atomic32_read_acqb(&function_calls);
actual_reds = reds = 0;
erts_smp_runq_lock(rq);
} else {
@@ -5282,14 +5347,14 @@ Process *schedule(Process *p, int calls)
| ERTS_RUNQ_FLG_CHK_CPU_BIND
| ERTS_RUNQ_FLG_SUSPENDED)) {
if ((rq->flags & ERTS_RUNQ_FLG_SUSPENDED)
- || (erts_smp_atomic32_read(&esdp->ssi->flags)
+ || (erts_smp_atomic32_read_acqb(&esdp->ssi->flags)
& ERTS_SSI_FLG_SUSPENDED)) {
ASSERT(erts_smp_atomic32_read(&esdp->ssi->flags)
& ERTS_SSI_FLG_SUSPENDED);
suspend_scheduler(esdp);
}
if ((rq->flags & ERTS_RUNQ_FLG_CHK_CPU_BIND)
- || erts_smp_atomic32_read(&esdp->chk_cpu_bind)) {
+ || erts_smp_atomic32_read_acqb(&esdp->chk_cpu_bind)) {
erts_sched_check_cpu_bind(esdp);
}
}
@@ -5340,7 +5405,7 @@ Process *schedule(Process *p, int calls)
if (rq->flags & (ERTS_RUNQ_FLG_SHARED_RUNQ
| ERTS_RUNQ_FLG_SUSPENDED)) {
if ((rq->flags & ERTS_RUNQ_FLG_SUSPENDED)
- || (erts_smp_atomic32_read(&esdp->ssi->flags)
+ || (erts_smp_atomic32_read_acqb(&esdp->ssi->flags)
& ERTS_SSI_FLG_SUSPENDED)) {
ASSERT(erts_smp_atomic32_read(&esdp->ssi->flags)
& ERTS_SSI_FLG_SUSPENDED);
@@ -5384,7 +5449,7 @@ Process *schedule(Process *p, int calls)
* Schedule system-level activities.
*/
- erts_smp_atomic32_set(&function_calls, 0);
+ erts_smp_atomic32_set_relb(&function_calls, 0);
fcalls = 0;
ASSERT(!erts_port_task_have_outstanding_io_tasks());
@@ -5426,7 +5491,7 @@ Process *schedule(Process *p, int calls)
if (erts_common_run_queue->waiting)
wake_scheduler(erts_common_run_queue, 0, 1);
}
- else if (erts_smp_atomic32_read(&no_empty_run_queues) != 0) {
+ else if (erts_smp_atomic32_read_acqb(&no_empty_run_queues) != 0) {
wake_scheduler_on_empty_runq(rq);
rq->wakeup_other = 0;
}