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authorRickard Green <[email protected]>2012-03-28 14:03:25 +0200
committerRickard Green <[email protected]>2012-04-23 11:48:49 +0200
commitb74e9a3d03d685345a8fa592b033a9d691e6e7c0 (patch)
treeb57b567ee50c28dbde1f7b6d245264bc1b9b20bc /erts
parentac7dcc23af68ef5a01ce5ca03ad485595bf5e18b (diff)
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Implement proposal for new scheduler wakeup strategy
Diffstat (limited to 'erts')
-rw-r--r--erts/doc/src/erl.xml11
-rw-r--r--erts/emulator/beam/erl_init.c16
-rw-r--r--erts/emulator/beam/erl_process.c269
-rw-r--r--erts/emulator/beam/erl_process.h3
-rw-r--r--erts/etc/common/erlexec.c1
-rw-r--r--erts/vsn.mk2
6 files changed, 255 insertions, 47 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 50f90ec9df..33a6339b04 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -867,6 +867,17 @@
<p>For more information, see
<seealso marker="erlang#system_flag_cpu_topology">erlang:system_flag(cpu_topology, CpuTopology)</seealso>.</p>
</item>
+ <tag><marker id="+sws"><c>+sws default|legacy|proposal</c></marker></tag>
+ <item>
+ <p>Set scheduler wakeup strategy. Default is <c>legacy</c> (has been
+ used since OTP-R13B). The <c>proposal</c> strategy is the currently
+ proposed strategy for OTP-R16. Note that the <c>proposal</c> strategy
+ might change during OTP-R15.
+ </p>
+ <p><em>NOTE:</em> This flag may be removed or changed at any time
+ without prior notice.
+ </p>
+ </item>
<tag><marker id="+swt"><c>+swt very_low|low|medium|high|very_high</c></marker></tag>
<item>
<p>Set scheduler wakeup threshold. Default is <c>medium</c>.
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 02efd2adb6..066ceff194 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -514,6 +514,8 @@ void erts_usage(void)
erts_fprintf(stderr, " see the erl(1) documentation for more info.\n");
erts_fprintf(stderr, "-sct cput set cpu topology,\n");
erts_fprintf(stderr, " see the erl(1) documentation for more info.\n");
+ erts_fprintf(stderr, "-sws val set scheduler wakeup strategy, valid values are:\n");
+ erts_fprintf(stderr, " default|legacy|proposal.\n");
erts_fprintf(stderr, "-swt val set scheduler wakeup threshold, valid values are:\n");
erts_fprintf(stderr, " very_low|low|medium|high|very_high.\n");
erts_fprintf(stderr, "-sss size suggested stack size in kilo words for scheduler threads,\n");
@@ -1217,13 +1219,23 @@ erl_start(int argc, char **argv)
use_multi_run_queue = 0;
else if (sys_strcmp("wt", sub_param) == 0) {
arg = get_arg(sub_param+2, argv[i+1], &i);
- if (erts_sched_set_wakeup_limit(arg) != 0) {
+ if (erts_sched_set_wakeup_other_thresold(arg) != 0) {
erts_fprintf(stderr, "scheduler wakeup threshold: %s\n",
arg);
erts_usage();
}
VERBOSE(DEBUG_SYSTEM,
- ("scheduler wakup threshold: %s\n", arg));
+ ("scheduler wakeup threshold: %s\n", arg));
+ }
+ else if (sys_strcmp("ws", sub_param) == 0) {
+ arg = get_arg(sub_param+2, argv[i+1], &i);
+ if (erts_sched_set_wakeup_other_type(arg) != 0) {
+ erts_fprintf(stderr, "scheduler wakeup strategy: %s\n",
+ arg);
+ erts_usage();
+ }
+ VERBOSE(DEBUG_SYSTEM,
+ ("scheduler wakeup threshold: %s\n", arg));
}
else if (has_prefix("ss", sub_param)) {
/* suggested stack size (Kilo Words) for scheduler threads */
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index dba57e04ca..229e3c52dd 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -54,15 +54,6 @@
(ERTS_SCHED_SYS_SLEEP_SPINCOUNT*ERTS_SCHED_TSE_SLEEP_SPINCOUNT_FACT)
#define ERTS_SCHED_SUSPEND_SLEEP_SPINCOUNT 0
-#define ERTS_WAKEUP_OTHER_LIMIT_VERY_HIGH (200*CONTEXT_REDS)
-#define ERTS_WAKEUP_OTHER_LIMIT_HIGH (50*CONTEXT_REDS)
-#define ERTS_WAKEUP_OTHER_LIMIT_MEDIUM (10*CONTEXT_REDS)
-#define ERTS_WAKEUP_OTHER_LIMIT_LOW (CONTEXT_REDS)
-#define ERTS_WAKEUP_OTHER_LIMIT_VERY_LOW (CONTEXT_REDS/10)
-
-#define ERTS_WAKEUP_OTHER_DEC 10
-#define ERTS_WAKEUP_OTHER_FIXED_INC (CONTEXT_REDS/10)
-
#if 0 || defined(DEBUG)
#define ERTS_FAKE_SCHED_BIND_PRINT_SORTED_CPU_DATA
#endif
@@ -116,8 +107,6 @@ Uint erts_no_schedulers;
Uint erts_max_processes = ERTS_DEFAULT_MAX_PROCESSES;
Uint erts_process_tab_index_mask;
-static int wakeup_other_limit;
-
int erts_sched_thread_suggested_stack_size = -1;
#ifdef ERTS_ENABLE_LOCK_CHECK
@@ -2554,30 +2543,243 @@ erts_debug_nbalance(void)
#endif
}
+/* Wakeup other schedulers */
+
+typedef enum {
+ ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_HIGH,
+ ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_HIGH,
+ ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_MEDIUM,
+ ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_LOW,
+ ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_LOW
+} ErtsSchedWakeupOtherThreshold;
+
+typedef enum {
+ ERTS_SCHED_WAKEUP_OTHER_TYPE_PROPOSAL,
+ ERTS_SCHED_WAKEUP_OTHER_TYPE_LEGACY
+} ErtsSchedWakeupOtherType;
+
+/* First proposal */
+
+#define ERTS_WAKEUP_OTHER_LIMIT_VERY_HIGH (200*CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_HIGH (50*CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_MEDIUM (10*CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_LOW (CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_VERY_LOW (CONTEXT_REDS/10)
+
+#define ERTS_WAKEUP_OTHER_DEC_SHIFT_VERY_HIGH 3
+#define ERTS_WAKEUP_OTHER_DEC_SHIFT_HIGH 1
+#define ERTS_WAKEUP_OTHER_DEC_SHIFT_MEDIUM 0
+#define ERTS_WAKEUP_OTHER_DEC_SHIFT_LOW -2
+#define ERTS_WAKEUP_OTHER_DEC_SHIFT_VERY_LOW -5
+
+#define ERTS_WAKEUP_OTHER_DEC_SHIFT 2
+#define ERTS_WAKEUP_OTHER_FIXED_INC (CONTEXT_REDS/10)
+
+/* To be legacy */
+
+#define ERTS_WAKEUP_OTHER_LIMIT_VERY_HIGH_LEGACY (200*CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_HIGH_LEGACY (50*CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_MEDIUM_LEGACY (10*CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_LOW_LEGACY (CONTEXT_REDS)
+#define ERTS_WAKEUP_OTHER_LIMIT_VERY_LOW_LEGACY (CONTEXT_REDS/10)
+
+#define ERTS_WAKEUP_OTHER_DEC_LEGACY 10
+#define ERTS_WAKEUP_OTHER_FIXED_INC_LEGACY (CONTEXT_REDS/10)
+
+#ifdef ERTS_SMP
+
+static struct {
+ ErtsSchedWakeupOtherThreshold threshold;
+ ErtsSchedWakeupOtherType type;
+ int limit;
+ int dec_shift;
+ int dec_mask;
+ void (*check)(ErtsRunQueue *rq);
+} wakeup_other;
+
+static void
+wakeup_other_check(ErtsRunQueue *rq)
+{
+ int wo_reds = rq->wakeup_other_reds;
+ if (wo_reds) {
+ int left_len = rq->len - 1;
+ if (left_len < 1) {
+ int wo_reduce = wo_reds << wakeup_other.dec_shift;
+ wo_reduce &= wakeup_other.dec_mask;
+ rq->wakeup_other -= wo_reduce;
+ if (rq->wakeup_other < 0)
+ rq->wakeup_other = 0;
+ }
+ else {
+ rq->wakeup_other += (left_len*wo_reds
+ + ERTS_WAKEUP_OTHER_FIXED_INC);
+ if (rq->wakeup_other > wakeup_other.limit) {
+ if (erts_common_run_queue) {
+ if (erts_common_run_queue->waiting)
+ wake_scheduler(erts_common_run_queue, 0, 1);
+ }
+ else {
+ int empty_rqs =
+ erts_smp_atomic32_read_acqb(&no_empty_run_queues);
+ if (empty_rqs != 0)
+ wake_scheduler_on_empty_runq(rq);
+ }
+ rq->wakeup_other = 0;
+ }
+ }
+ rq->wakeup_other_reds = 0;
+ }
+}
+
+static void
+wakeup_other_set_limit(void)
+{
+ switch (wakeup_other.threshold) {
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_HIGH:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_VERY_HIGH;
+ wakeup_other.dec_shift = ERTS_WAKEUP_OTHER_DEC_SHIFT_VERY_HIGH;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_HIGH:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_HIGH;
+ wakeup_other.dec_shift = ERTS_WAKEUP_OTHER_DEC_SHIFT_HIGH;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_MEDIUM:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_MEDIUM;
+ wakeup_other.dec_shift = ERTS_WAKEUP_OTHER_DEC_SHIFT_MEDIUM;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_LOW:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_LOW;
+ wakeup_other.dec_shift = ERTS_WAKEUP_OTHER_DEC_SHIFT_LOW;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_LOW:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_VERY_LOW;
+ wakeup_other.dec_shift = ERTS_WAKEUP_OTHER_DEC_SHIFT_VERY_LOW;
+ break;
+ }
+ if (wakeup_other.dec_shift < 0)
+ wakeup_other.dec_mask = (1 << (sizeof(wakeup_other.dec_mask)*8
+ + wakeup_other.dec_shift)) - 1;
+ else {
+ wakeup_other.dec_mask = 0;
+ wakeup_other.dec_mask = ~wakeup_other.dec_mask;
+ }
+}
+
+static void
+wakeup_other_check_legacy(ErtsRunQueue *rq)
+{
+ int wo_reds = rq->wakeup_other_reds;
+ if (wo_reds) {
+ if (rq->len < 2) {
+ rq->wakeup_other -= ERTS_WAKEUP_OTHER_DEC_LEGACY*wo_reds;
+ if (rq->wakeup_other < 0)
+ rq->wakeup_other = 0;
+ }
+ else if (rq->wakeup_other < wakeup_other.limit)
+ rq->wakeup_other += rq->len*wo_reds + ERTS_WAKEUP_OTHER_FIXED_INC_LEGACY;
+ else {
+ if (erts_common_run_queue) {
+ if (erts_common_run_queue->waiting)
+ wake_scheduler(erts_common_run_queue, 0, 1);
+ }
+ else if (erts_smp_atomic32_read_acqb(&no_empty_run_queues) != 0) {
+ wake_scheduler_on_empty_runq(rq);
+ rq->wakeup_other = 0;
+ }
+ rq->wakeup_other = 0;
+ }
+ }
+ rq->wakeup_other_reds = 0;
+}
+
+static void
+wakeup_other_set_limit_legacy(void)
+{
+ switch (wakeup_other.threshold) {
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_HIGH:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_VERY_HIGH_LEGACY;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_HIGH:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_HIGH_LEGACY;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_MEDIUM:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_MEDIUM_LEGACY;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_LOW:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_LOW_LEGACY;
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_LOW:
+ wakeup_other.limit = ERTS_WAKEUP_OTHER_LIMIT_VERY_LOW_LEGACY;
+ break;
+ }
+}
+
+static void
+set_wakeup_other_data(void)
+{
+ switch (wakeup_other.type) {
+ case ERTS_SCHED_WAKEUP_OTHER_TYPE_PROPOSAL:
+ wakeup_other.check = wakeup_other_check;
+ wakeup_other_set_limit();
+ break;
+ case ERTS_SCHED_WAKEUP_OTHER_TYPE_LEGACY:
+ wakeup_other.check = wakeup_other_check_legacy;
+ wakeup_other_set_limit_legacy();
+ break;
+ }
+}
+
+#endif
+
void
erts_early_init_scheduling(void)
{
- wakeup_other_limit = ERTS_WAKEUP_OTHER_LIMIT_MEDIUM;
+#ifdef ERTS_SMP
+ wakeup_other.threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_MEDIUM;
+ wakeup_other.type = ERTS_SCHED_WAKEUP_OTHER_TYPE_LEGACY;
+#endif
}
int
-erts_sched_set_wakeup_limit(char *str)
+erts_sched_set_wakeup_other_thresold(char *str)
{
+ ErtsSchedWakeupOtherThreshold threshold;
if (sys_strcmp(str, "very_high") == 0)
- wakeup_other_limit = ERTS_WAKEUP_OTHER_LIMIT_VERY_HIGH;
+ threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_HIGH;
else if (sys_strcmp(str, "high") == 0)
- wakeup_other_limit = ERTS_WAKEUP_OTHER_LIMIT_HIGH;
+ threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_HIGH;
else if (sys_strcmp(str, "medium") == 0)
- wakeup_other_limit = ERTS_WAKEUP_OTHER_LIMIT_MEDIUM;
+ threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_MEDIUM;
else if (sys_strcmp(str, "low") == 0)
- wakeup_other_limit = ERTS_WAKEUP_OTHER_LIMIT_LOW;
+ threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_LOW;
else if (sys_strcmp(str, "very_low") == 0)
- wakeup_other_limit = ERTS_WAKEUP_OTHER_LIMIT_VERY_LOW;
+ threshold = ERTS_SCHED_WAKEUP_OTHER_THRESHOLD_VERY_LOW;
else
return EINVAL;
+#ifdef ERTS_SMP
+ wakeup_other.threshold = threshold;
+ set_wakeup_other_data();
+#endif
+ return 0;
+}
+
+int
+erts_sched_set_wakeup_other_type(char *str)
+{
+ ErtsSchedWakeupOtherType type;
+ if (sys_strcmp(str, "proposal") == 0)
+ type = ERTS_SCHED_WAKEUP_OTHER_TYPE_PROPOSAL;
+ else if (sys_strcmp(str, "default") == 0)
+ type = ERTS_SCHED_WAKEUP_OTHER_TYPE_LEGACY;
+ else if (sys_strcmp(str, "legacy") == 0)
+ type = ERTS_SCHED_WAKEUP_OTHER_TYPE_LEGACY;
+ else
+ return EINVAL;
+#ifdef ERTS_SMP
+ wakeup_other.type = type;
+#endif
return 0;
}
-
void
erts_init_scheduling(int mrq, int no_schedulers, int no_schedulers_online)
@@ -2590,6 +2792,10 @@ erts_init_scheduling(int mrq, int no_schedulers, int no_schedulers_online)
init_misc_op_list_alloc();
+#ifdef ERTS_SMP
+ set_wakeup_other_data();
+#endif
+
ASSERT(no_schedulers_online <= no_schedulers);
ASSERT(no_schedulers_online >= 1);
ASSERT(no_schedulers >= 1);
@@ -5480,30 +5686,7 @@ Process *schedule(Process *p, int calls)
exec_misc_ops(rq);
#ifdef ERTS_SMP
- {
- int wo_reds = rq->wakeup_other_reds;
- if (wo_reds) {
- if (rq->len < 2) {
- rq->wakeup_other -= ERTS_WAKEUP_OTHER_DEC*wo_reds;
- if (rq->wakeup_other < 0)
- rq->wakeup_other = 0;
- }
- else if (rq->wakeup_other < wakeup_other_limit)
- rq->wakeup_other += rq->len*wo_reds + ERTS_WAKEUP_OTHER_FIXED_INC;
- else {
- if (erts_common_run_queue) {
- if (erts_common_run_queue->waiting)
- wake_scheduler(erts_common_run_queue, 0, 1);
- }
- else if (erts_smp_atomic32_read_acqb(&no_empty_run_queues) != 0) {
- wake_scheduler_on_empty_runq(rq);
- rq->wakeup_other = 0;
- }
- rq->wakeup_other = 0;
- }
- }
- rq->wakeup_other_reds = 0;
- }
+ wakeup_other.check(rq);
#endif
/*
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index c7d89d3bb3..d2f0c67597 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -1040,7 +1040,8 @@ ErtsProcList *erts_proclist_create(Process *);
void erts_proclist_destroy(ErtsProcList *);
int erts_proclist_same(ErtsProcList *, Process *);
-int erts_sched_set_wakeup_limit(char *str);
+int erts_sched_set_wakeup_other_thresold(char *str);
+int erts_sched_set_wakeup_other_type(char *str);
#ifdef DEBUG
void erts_dbg_multi_scheduling_return_trap(Process *, Eterm);
diff --git a/erts/etc/common/erlexec.c b/erts/etc/common/erlexec.c
index 95cb688b29..59bc7229e4 100644
--- a/erts/etc/common/erlexec.c
+++ b/erts/etc/common/erlexec.c
@@ -125,6 +125,7 @@ static char *pluss_val_switches[] = {
"cl",
"ct",
"wt",
+ "ws",
"ss",
NULL
};
diff --git a/erts/vsn.mk b/erts/vsn.mk
index 6be703d453..5af5db3c94 100644
--- a/erts/vsn.mk
+++ b/erts/vsn.mk
@@ -17,7 +17,7 @@
# %CopyrightEnd%
#
-VSN = 5.8.4.1
+VSN = 5.8.4.1.0.2
SYSTEM_VSN = R14B03
# Port number 4365 in 4.2