From ac7dcc23af68ef5a01ce5ca03ad485595bf5e18b Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Wed, 9 Nov 2011 17:21:20 +0100 Subject: Add switch that can disable scheduler compaction of load --- erts/doc/src/erl.xml | 13 +++++++++++++ erts/emulator/beam/erl_init.c | 16 ++++++++++++++++ erts/emulator/beam/erl_process.c | 4 ++++ erts/emulator/beam/erl_process.h | 1 + erts/etc/common/erlexec.c | 1 + 5 files changed, 35 insertions(+) diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml index 514ee5ffaf..50f90ec9df 100644 --- a/erts/doc/src/erl.xml +++ b/erts/doc/src/erl.xml @@ -738,6 +738,19 @@ erlang:system_flag(scheduler_bind_type, SchedulerBindType).

+ +scl true|false + +

Enable or disable scheduler compaction of load. By default + scheduler compaction of load is enabled. When enabled, load + balancing will strive for a load distribution which causes + as many scheduler threads as possible to be fully loaded (i.e., + not run out of work). This is accomplished by migrating load + (e.g. runnable processes) into a smaller set of schedulers + when schedulers frequently run out of work. When disabled, + the frequency with which schedulers run out of work will + not be taken into account by the load balancing logic. +

+ +sct CpuTopology diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c index 0a57eb6d88..02efd2adb6 100644 --- a/erts/emulator/beam/erl_init.c +++ b/erts/emulator/beam/erl_init.c @@ -510,6 +510,8 @@ 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, "-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"); erts_fprintf(stderr, " see the erl(1) documentation for more info.\n"); erts_fprintf(stderr, "-swt val set scheduler wakeup threshold, valid values are:\n"); @@ -605,6 +607,7 @@ early_init(int *argc, char **argv) /* int max_reader_groups; int reader_groups; + erts_sched_compact_load = 1; use_multi_run_queue = 1; erts_printf_eterm_func = erts_printf_term; erts_disable_tolerant_timeofday = 0; @@ -1150,6 +1153,19 @@ erl_start(int argc, char **argv) erts_usage(); } } + else if (has_prefix("cl", sub_param)) { + arg = get_arg(sub_param+2, argv[i+1], &i); + if (sys_strcmp("true", arg) == 0) + erts_sched_compact_load = 1; + else if (sys_strcmp("false", arg) == 0) + erts_sched_compact_load = 0; + else { + erts_fprintf(stderr, + "bad scheduler compact load value '%s'\n", + arg); + erts_usage(); + } + } else if (has_prefix("ct", sub_param)) { arg = get_arg(sub_param+2, argv[i+1], &i); res = erts_init_cpu_topology_string(arg); diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c index 2704359a8f..dba57e04ca 100644 --- a/erts/emulator/beam/erl_process.c +++ b/erts/emulator/beam/erl_process.c @@ -111,6 +111,7 @@ static Sint p_serial; static Uint p_serial_mask; static Uint p_serial_shift; +int erts_sched_compact_load; Uint erts_no_schedulers; Uint erts_max_processes = ERTS_DEFAULT_MAX_PROCESSES; Uint erts_process_tab_index_mask; @@ -2215,6 +2216,9 @@ check_balance(ErtsRunQueue *c_rq) mmax_len = run_queue_info[qix].max_len; } + if (!erts_sched_compact_load) + goto all_active; + if (!forced && half_full_scheds != blnc_no_rqs) { int min = 1; if (min < half_full_scheds) diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h index 296acc7367..c7d89d3bb3 100644 --- a/erts/emulator/beam/erl_process.h +++ b/erts/emulator/beam/erl_process.h @@ -88,6 +88,7 @@ struct saved_calls { }; extern Export exp_send, exp_receive, exp_timeout; +extern int erts_sched_compact_load; extern Uint erts_no_schedulers; extern Uint erts_no_run_queues; extern int erts_sched_thread_suggested_stack_size; diff --git a/erts/etc/common/erlexec.c b/erts/etc/common/erlexec.c index 2bd576d8e8..95cb688b29 100644 --- a/erts/etc/common/erlexec.c +++ b/erts/etc/common/erlexec.c @@ -122,6 +122,7 @@ static char *plusM_other_switches[] = { /* +s arguments with values */ static char *pluss_val_switches[] = { "bt", + "cl", "ct", "wt", "ss", -- cgit v1.2.3