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-rw-r--r--erts/doc/src/erl.xml10
-rw-r--r--erts/emulator/beam/erl_init.c12
-rw-r--r--erts/emulator/beam/erl_process.c75
-rw-r--r--erts/emulator/beam/erl_process.h1
-rw-r--r--erts/etc/common/erlexec.c1
5 files changed, 93 insertions, 6 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index f23e8bd9b8..72cbf1f3b2 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -766,6 +766,16 @@
<seealso marker="erlang#system_info_scheduler_bindings">erlang:system_info(scheduler_bindings)</seealso>.
</p>
</item>
+ <tag><marker id="+sbwt"><c>+sbwt none|very_short|short|medium|long|very_long</c></marker></tag>
+ <item>
+ <p>Set scheduler busy wait threshold. Default is <c>medium</c>.
+ The threshold determines how long schedulers should busy
+ wait when running out of work before going to sleep.
+ </p>
+ <p><em>NOTE:</em> This flag may be removed or changed at any time
+ without prior notice.
+ </p>
+ </item>
<tag><marker id="+scl"><c>+scl true|false</c></marker></tag>
<item>
<p>Enable or disable scheduler compaction of load. By default
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index faf980b237..8bcba9de15 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -511,6 +511,8 @@ void erts_usage(void)
erts_fprintf(stderr, "-rg amount set reader groups limit\n");
erts_fprintf(stderr, "-sbt type set scheduler bind type, valid types are:\n");
erts_fprintf(stderr, " u|ns|ts|ps|s|nnts|nnps|tnnps|db\n");
+ erts_fprintf(stderr, "-sbwt val set scheduler busy wait threshold, valid values are:\n");
+ erts_fprintf(stderr, " none|very_short|short|medium|long|very_long.\n");
erts_fprintf(stderr, "-scl bool enable/disable compaction of scheduler load,\n");
erts_fprintf(stderr, " see the erl(1) documentation for more info.\n");
erts_fprintf(stderr, "-sct cput set cpu topology,\n");
@@ -1200,6 +1202,16 @@ erl_start(int argc, char **argv)
erts_usage();
}
}
+ else if (has_prefix("bwt", sub_param)) {
+ arg = get_arg(sub_param+3, argv[i+1], &i);
+ if (erts_sched_set_busy_wait_threshold(arg) != 0) {
+ erts_fprintf(stderr, "bad scheduler busy wait threshold: %s\n",
+ arg);
+ erts_usage();
+ }
+ VERBOSE(DEBUG_SYSTEM,
+ ("scheduler wakup threshold: %s\n", arg));
+ }
else if (has_prefix("cl", sub_param)) {
arg = get_arg(sub_param+2, argv[i+1], &i);
if (sys_strcmp("true", arg) == 0)
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 3a70f0de0e..09ca536188 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -52,10 +52,20 @@
#define ERTS_SCHED_SPIN_UNTIL_YIELD 100
-#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT 10
+#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT_VERY_LONG 40
+#define ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_VERY_LONG 1000
+#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT_LONG 20
+#define ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_LONG 1000
+#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT_MEDIUM 10
+#define ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_MEDIUM 1000
+#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT_SHORT 10
+#define ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_SHORT 0
+#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT_VERY_SHORT 5
+#define ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_VERY_SHORT 0
+#define ERTS_SCHED_SYS_SLEEP_SPINCOUNT_NONE 0
+#define ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_NONE 0
+
#define ERTS_SCHED_TSE_SLEEP_SPINCOUNT_FACT 1000
-#define ERTS_SCHED_TSE_SLEEP_SPINCOUNT \
- (ERTS_SCHED_SYS_SLEEP_SPINCOUNT*ERTS_SCHED_TSE_SLEEP_SPINCOUNT_FACT)
#define ERTS_SCHED_SUSPEND_SLEEP_SPINCOUNT 0
#if 0 || defined(DEBUG)
@@ -120,6 +130,12 @@ int erts_sched_thread_suggested_stack_size = -1;
ErtsLcPSDLocks erts_psd_required_locks[ERTS_PSD_SIZE];
#endif
+static struct {
+ int aux_work;
+ int tse;
+ int sys_schedule;
+} sched_busy_wait;
+
#ifdef ERTS_SMP
int erts_disable_proc_not_running_opt;
@@ -2035,7 +2051,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
erts_smp_runq_unlock(rq);
- spincount = ERTS_SCHED_TSE_SLEEP_SPINCOUNT;
+ spincount = sched_busy_wait.tse;
tse_wait:
@@ -2086,7 +2102,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
}
flgs = sched_prep_cont_spin_wait(ssi);
- spincount = ERTS_SCHED_TSE_SLEEP_SPINCOUNT;
+ spincount = sched_busy_wait.aux_work;
if (!(flgs & ERTS_SSI_FLG_WAITING)) {
ASSERT(!(flgs & ERTS_SSI_FLG_SLEEPING));
@@ -2123,7 +2139,9 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
ASSERT(working);
sched_wall_time_change(esdp, working = 0);
- spincount = ERTS_SCHED_SYS_SLEEP_SPINCOUNT;
+ spincount = sched_busy_wait.sys_schedule;
+ if (spincount == 0)
+ goto sys_aux_work;
while (spincount-- > 0) {
@@ -3735,6 +3753,11 @@ erts_early_init_scheduling(int no_schedulers)
wakeup_other.threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_MEDIUM;
wakeup_other.type = ERTS_SCHED_WAKEUP_OTHER_TYPE_LEGACY;
#endif
+ sched_busy_wait.sys_schedule = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_MEDIUM;
+ sched_busy_wait.tse = (ERTS_SCHED_SYS_SLEEP_SPINCOUNT_MEDIUM
+ * ERTS_SCHED_TSE_SLEEP_SPINCOUNT_FACT);
+ sched_busy_wait.aux_work = (ERTS_SCHED_SYS_SLEEP_SPINCOUNT_MEDIUM
+ * ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_MEDIUM);
}
int
@@ -3778,6 +3801,46 @@ erts_sched_set_wakeup_other_type(char *str)
return 0;
}
+int
+erts_sched_set_busy_wait_threshold(char *str)
+{
+ int sys_sched;
+ int aux_work_fact;
+
+ if (sys_strcmp(str, "very_long") == 0) {
+ sys_sched = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_VERY_LONG;
+ aux_work_fact = ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_VERY_LONG;
+ }
+ else if (sys_strcmp(str, "long") == 0) {
+ sys_sched = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_LONG;
+ aux_work_fact = ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_LONG;
+ }
+ else if (sys_strcmp(str, "medium") == 0) {
+ sys_sched = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_MEDIUM;
+ aux_work_fact = ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_MEDIUM;
+ }
+ else if (sys_strcmp(str, "short") == 0) {
+ sys_sched = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_SHORT;
+ aux_work_fact = ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_SHORT;
+ }
+ else if (sys_strcmp(str, "very_short") == 0) {
+ sys_sched = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_VERY_SHORT;
+ aux_work_fact = ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_VERY_SHORT;
+ }
+ else if (sys_strcmp(str, "none") == 0) {
+ sys_sched = ERTS_SCHED_SYS_SLEEP_SPINCOUNT_NONE;
+ aux_work_fact = ERTS_SCHED_AUX_WORK_SLEEP_SPINCOUNT_FACT_NONE;
+ }
+ else {
+ return EINVAL;
+ }
+
+ sched_busy_wait.sys_schedule = sys_sched;
+ sched_busy_wait.tse = sys_sched*ERTS_SCHED_TSE_SLEEP_SPINCOUNT_FACT;
+ sched_busy_wait.aux_work = sys_sched*aux_work_fact;
+
+ return 0;
+}
static void
init_aux_work_data(ErtsAuxWorkData *awdp, ErtsSchedulerData *esdp)
{
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index ec2ba0f924..2683b8540d 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -1098,6 +1098,7 @@ int erts_proclist_same(ErtsProcList *, Process *);
int erts_sched_set_wakeup_other_thresold(char *str);
int erts_sched_set_wakeup_other_type(char *str);
+int erts_sched_set_busy_wait_threshold(char *str);
#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
int erts_dbg_check_halloc_lock(Process *p);
diff --git a/erts/etc/common/erlexec.c b/erts/etc/common/erlexec.c
index 56428e889b..c9aee16def 100644
--- a/erts/etc/common/erlexec.c
+++ b/erts/etc/common/erlexec.c
@@ -121,6 +121,7 @@ static char *plusM_other_switches[] = {
/* +s arguments with values */
static char *pluss_val_switches[] = {
"bt",
+ "bwt",
"cl",
"ct",
"wt",
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-07 15:41:05 +0000