From b74e9a3d03d685345a8fa592b033a9d691e6e7c0 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Wed, 28 Mar 2012 14:03:25 +0200 Subject: Implement proposal for new scheduler wakeup strategy --- erts/doc/src/erl.xml | 11 ++ erts/emulator/beam/erl_init.c | 16 ++- erts/emulator/beam/erl_process.c | 269 ++++++++++++++++++++++++++++++++------- erts/emulator/beam/erl_process.h | 3 +- erts/etc/common/erlexec.c | 1 + erts/vsn.mk | 2 +- 6 files changed, 255 insertions(+), 47 deletions(-) (limited to 'erts') 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 @@

For more information, see erlang:system_flag(cpu_topology, CpuTopology).

+ +sws default|legacy|proposal + +

Set scheduler wakeup strategy. Default is legacy (has been + used since OTP-R13B). The proposal strategy is the currently + proposed strategy for OTP-R16. Note that the proposal strategy + might change during OTP-R15. +

+

NOTE: This flag may be removed or changed at any time + without prior notice. +

+ +swt very_low|low|medium|high|very_high

Set scheduler wakeup threshold. Default is medium. 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 -- cgit v1.2.3