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-rw-r--r--erts/doc/src/erl.xml50
-rw-r--r--erts/emulator/beam/erl_init.c169
-rw-r--r--erts/emulator/test/scheduler_SUITE.erl64
-rw-r--r--erts/etc/common/erlexec.c18
4 files changed, 238 insertions, 63 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 70569b1c6c..c16b45856d 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -748,19 +748,47 @@
</item>
<tag><marker id="+S"><c><![CDATA[+S Schedulers:SchedulerOnline]]></c></marker></tag>
<item>
- <p>Sets the amount of scheduler threads to create and scheduler
- threads to set online when SMP support has been enabled.
- Valid range for both values are 1-1024. If the
- Erlang runtime system is able to determine the amount
- of logical processors configured and logical processors available,
- <c>Schedulers</c> will default to logical processors configured,
- and <c>SchedulersOnline</c> will default to logical processors
- available; otherwise, the default values will be 1. <c>Schedulers</c>
- may be omitted if <c>:SchedulerOnline</c> is not and vice versa. The
- amount of schedulers online can be changed at run time via
+ <p>Sets the number of scheduler threads to create and scheduler
+ threads to set online when SMP support has been enabled. The maximum for
+ both values is 1024. If the Erlang runtime system is able to determine the
+ amount of logical processors configured and logical processors available,
+ <c>Schedulers</c> will default to logical processors configured, and
+ <c>SchedulersOnline</c> will default to logical processors available;
+ otherwise, the default values will be 1. <c>Schedulers</c> may be omitted
+ if <c>:SchedulerOnline</c> is not and vice versa. The number of schedulers
+ online can be changed at run time via
<seealso marker="erlang#system_flag_schedulers_online">erlang:system_flag(schedulers_online, SchedulersOnline)</seealso>.
</p>
- <p>This flag will be ignored if the emulator doesn't have
+ <p>If <c>Schedulers</c> or <c>SchedulersOnline</c> is specified as a
+ negative number, the value is subtracted from the default number of
+ logical processors configured or logical processors available, respectively.
+ </p>
+ <p>Specifying the value 0 for <c>Schedulers</c> or <c>SchedulersOnline</c>
+ resets the number of scheduler threads or scheduler threads online respectively
+ to its default value.
+ </p>
+ <p>This option is ignored if the emulator doesn't have
+ SMP support enabled (see the <seealso marker="#smp">-smp</seealso>
+ flag).</p>
+ </item>
+ <tag><marker id="+SP"><c><![CDATA[+SP SchedulersPercentage:SchedulersOnlinePercentage]]></c></marker></tag>
+ <item>
+ <p>Similar to <seealso marker="#+S">+S</seealso> but uses percentages to set the
+ number of scheduler threads to create, based on logical processors configured,
+ and scheduler threads to set online, based on logical processors available, when
+ SMP support has been enabled. Specified values must be greater than 0. For example,
+ <c>+SP 50:25</c> sets the number of scheduler threads to 50% of the logical processors
+ configured and the number of scheduler threads online to 25% of the logical processors available.
+ <c>SchedulersPercentage</c> may be omitted if <c>:SchedulersOnlinePercentage</c> is
+ not and vice versa. The number of schedulers online can be changed at run time via
+ <seealso marker="erlang#system_flag_schedulers_online">erlang:system_flag(schedulers_online, SchedulersOnline)</seealso>.
+ </p>
+ <p>This option interacts with <seealso marker="#+S">+S</seealso> settings.
+ For example, on a system with 8 logical cores configured and 8 logical cores
+ available, the combination of the options <c>+S 4:4 +SP 50:25</c> (in either order)
+ results in 2 scheduler threads (50% of 4) and 1 scheduler thread online (25% of 4).
+ </p>
+ <p>This option is ignored if the emulator doesn't have
SMP support enabled (see the <seealso marker="#smp">-smp</seealso>
flag).</p>
</item>
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 8d137df7ae..f7bfa91b54 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -549,9 +549,12 @@ void erts_usage(void)
ERTS_SCHED_THREAD_MAX_STACK_SIZE);
erts_fprintf(stderr, "-spp Bool set port parallelism scheduling hint\n");
erts_fprintf(stderr, "-S n1:n2 set number of schedulers (n1), and number of\n");
- erts_fprintf(stderr, " schedulers online (n2), valid range for both\n");
- erts_fprintf(stderr, " numbers are [1-%d]\n",
+ erts_fprintf(stderr, " schedulers online (n2), maximum for both\n");
+ erts_fprintf(stderr, " numbers is %d\n",
ERTS_MAX_NO_OF_SCHEDULERS);
+ erts_fprintf(stderr, "-SP p1:p2 specify schedulers (p1) and schedulers online (p2)\n");
+ erts_fprintf(stderr, " as percentages of logical processors configured and logical\n");
+ erts_fprintf(stderr, " processors available, respectively\n");
erts_fprintf(stderr, "-t size set the maximum number of atoms the "
"emulator can handle\n");
erts_fprintf(stderr, " valid range is [%d-%d]\n",
@@ -631,6 +634,8 @@ early_init(int *argc, char **argv) /*
int ncpuavail;
int schdlrs;
int schdlrs_onln;
+ int schdlrs_percentage = 100;
+ int schdlrs_onln_percentage = 100;
int max_main_threads;
int max_reader_groups;
int reader_groups;
@@ -758,63 +763,128 @@ early_init(int *argc, char **argv) /*
}
break;
}
- case 'S' : {
- int tot, onln;
- char *arg = get_arg(argv[i]+2, argv[i+1], &i);
- switch (sscanf(arg, "%d:%d", &tot, &onln)) {
- case 0:
- switch (sscanf(arg, ":%d", &onln)) {
+ case 'S' :
+ if (argv[i][2] == 'P') {
+ int ptot, ponln;
+ char *arg = get_arg(argv[i]+3, argv[i+1], &i);
+ switch (sscanf(arg, "%d:%d", &ptot, &ponln)) {
+ case 0:
+ switch (sscanf(arg, ":%d", &ponln)) {
+ case 1:
+ if (ponln < 0)
+ goto bad_SP;
+ ptot = 100;
+ goto chk_SP;
+ default:
+ goto bad_SP;
+ }
case 1:
- tot = no_schedulers;
- goto chk_S;
+ if (ptot < 0)
+ goto bad_SP;
+ ponln = ptot < 100 ? ptot : 100;
+ goto chk_SP;
+ case 2:
+ if (ptot < 0 || ponln < 0)
+ goto bad_SP;
+ chk_SP:
+ schdlrs_percentage = ptot;
+ schdlrs_onln_percentage = ponln;
+ break;
default:
- goto bad_S;
- }
- case 1:
- onln = tot < schdlrs_onln ? tot : schdlrs_onln;
- case 2:
- chk_S:
- if (tot > 0)
- schdlrs = tot;
- else
- schdlrs = no_schedulers + tot;
- if (onln > 0)
- schdlrs_onln = onln;
- else
- schdlrs_onln = no_schedulers_online + onln;
- if (schdlrs < 1 || ERTS_MAX_NO_OF_SCHEDULERS < schdlrs) {
- erts_fprintf(stderr,
- "bad amount of schedulers %d\n",
- tot);
- erts_usage();
- }
- if (schdlrs_onln < 1 || schdlrs < schdlrs_onln) {
+ bad_SP:
+ erts_fprintf(stderr,
+ "bad schedulers percentage specifier %s\n",
+ arg);
+ erts_usage();
+ break;
+ }
+
+ VERBOSE(DEBUG_SYSTEM,
+ ("using %d:%d scheduler percentages\n",
+ schdlrs_percentage, schdlrs_onln_percentage));
+ } else {
+ int tot, onln;
+ char *arg = get_arg(argv[i]+2, argv[i+1], &i);
+ switch (sscanf(arg, "%d:%d", &tot, &onln)) {
+ case 0:
+ switch (sscanf(arg, ":%d", &onln)) {
+ case 1:
+ tot = no_schedulers;
+ goto chk_S;
+ default:
+ goto bad_S;
+ }
+ case 1:
+ onln = tot < schdlrs_onln ? tot : schdlrs_onln;
+ case 2:
+ chk_S:
+ if (tot > 0)
+ schdlrs = tot;
+ else
+ schdlrs = no_schedulers + tot;
+ if (onln > 0)
+ schdlrs_onln = onln;
+ else
+ schdlrs_onln = no_schedulers_online + onln;
+ if (schdlrs < 1 || ERTS_MAX_NO_OF_SCHEDULERS < schdlrs) {
+ erts_fprintf(stderr,
+ "bad amount of schedulers %d\n",
+ tot);
+ erts_usage();
+ }
+ if (schdlrs_onln < 1 || schdlrs < schdlrs_onln) {
+ erts_fprintf(stderr,
+ "bad amount of schedulers online %d "
+ "(total amount of schedulers %d)\n",
+ schdlrs_onln, schdlrs);
+ erts_usage();
+ }
+ break;
+ default:
+ bad_S:
erts_fprintf(stderr,
- "bad amount of schedulers online %d "
- "(total amount of schedulers %d)\n",
- schdlrs_onln, schdlrs);
+ "bad amount of schedulers %s\n",
+ arg);
erts_usage();
+ break;
}
- break;
- default:
- bad_S:
- erts_fprintf(stderr,
- "bad amount of schedulers %s\n",
- arg);
- erts_usage();
- break;
- }
- VERBOSE(DEBUG_SYSTEM,
- ("using %d:%d scheduler(s)\n", tot, onln));
- break;
- }
+ VERBOSE(DEBUG_SYSTEM,
+ ("using %d:%d scheduler(s)\n", tot, onln));
+ }
+ break;
default:
break;
}
}
i++;
}
+
+#ifdef ERTS_SMP
+ /* apply any scheduler percentages */
+ if (schdlrs_percentage != 100 || schdlrs_onln_percentage != 100) {
+ schdlrs = schdlrs * schdlrs_percentage / 100;
+ schdlrs_onln = schdlrs_onln * schdlrs_onln_percentage / 100;
+ if (schdlrs < 1)
+ schdlrs = 1;
+ if (ERTS_MAX_NO_OF_SCHEDULERS < schdlrs) {
+ erts_fprintf(stderr,
+ "bad schedulers percentage %d "
+ "(total amount of schedulers %d)\n",
+ schdlrs_percentage, schdlrs);
+ erts_usage();
+ }
+ if (schdlrs_onln < 1)
+ schdlrs_onln = 1;
+ if (schdlrs < schdlrs_onln) {
+ erts_fprintf(stderr,
+ "bad schedulers online percentage %d "
+ "(total amount of schedulers %d, online %d)\n",
+ schdlrs_onln_percentage, schdlrs, schdlrs_onln);
+ erts_usage();
+ }
+ }
+#endif
}
#ifndef USE_THREADS
@@ -1312,7 +1382,10 @@ erl_start(int argc, char **argv)
break;
case 'S' : /* Was handled in early_init() just read past it */
- (void) get_arg(argv[i]+2, argv[i+1], &i);
+ if (argv[i][2] == 'P')
+ (void) get_arg(argv[i]+3, argv[i+1], &i);
+ else
+ (void) get_arg(argv[i]+2, argv[i+1], &i);
break;
case 's' : {
diff --git a/erts/emulator/test/scheduler_SUITE.erl b/erts/emulator/test/scheduler_SUITE.erl
index 8931562828..81539faa09 100644
--- a/erts/emulator/test/scheduler_SUITE.erl
+++ b/erts/emulator/test/scheduler_SUITE.erl
@@ -52,6 +52,7 @@
update_cpu_info/1,
sct_cmd/1,
sbt_cmd/1,
+ scheduler_threads/1,
scheduler_suspend/1,
reader_groups/1]).
@@ -66,7 +67,7 @@ all() ->
equal_with_part_time_max,
equal_and_high_with_part_time_max, equal_with_high,
equal_with_high_max, bound_process,
- {group, scheduler_bind}, scheduler_suspend,
+ {group, scheduler_bind}, scheduler_threads, scheduler_suspend,
reader_groups].
groups() ->
@@ -1039,7 +1040,66 @@ sbt_test(Config, CpuTCmd, ClBt, Bt, LP) ->
tuple_to_list(SB)),
?line stop_node(Node),
?line ok.
-
+
+scheduler_threads(Config) when is_list(Config) ->
+ SmpSupport = erlang:system_info(smp_support),
+ {Sched, SchedOnln, _} = get_sstate(Config, ""),
+ %% Configure half the number of both the scheduler threads and
+ %% the scheduler threads online.
+ {HalfSched, HalfSchedOnln} = case SmpSupport of
+ false -> {1,1};
+ true ->
+ {Sched div 2,
+ SchedOnln div 2}
+ end,
+ {HalfSched, HalfSchedOnln, _} = get_sstate(Config, "+SP 50:50"),
+ %% Use +S to configure 4x the number of scheduler threads and
+ %% 4x the number of scheduler threads online, but alter that
+ %% setting using +SP to 50% scheduler threads and 25% scheduler
+ %% threads online. The result should be 2x scheduler threads and
+ %% 1x scheduler threads online.
+ TwiceSched = case SmpSupport of
+ false -> 1;
+ true -> Sched*2
+ end,
+ FourSched = integer_to_list(Sched*4),
+ FourSchedOnln = integer_to_list(SchedOnln*4),
+ CombinedCmd1 = "+S "++FourSched++":"++FourSchedOnln++" +SP50:25",
+ {TwiceSched, SchedOnln, _} = get_sstate(Config, CombinedCmd1),
+ %% Now do the same test but with the +S and +SP options in the
+ %% opposite order, since order shouldn't matter.
+ CombinedCmd2 = "+SP50:25 +S "++FourSched++":"++FourSchedOnln,
+ {TwiceSched, SchedOnln, _} = get_sstate(Config, CombinedCmd2),
+ %% Apply two +SP options to make sure the second overrides the first
+ TwoCmd = "+SP 25:25 +SP 100:100",
+ {Sched, SchedOnln, _} = get_sstate(Config, TwoCmd),
+ %% Configure 50% of scheduler threads online only
+ {Sched, HalfSchedOnln, _} = get_sstate(Config, "+SP:50"),
+ %% Configure 2x scheduler threads only
+ {TwiceSched, SchedOnln, _} = get_sstate(Config, "+SP 200"),
+ %% Test resetting the scheduler counts
+ ResetCmd = "+S "++FourSched++":"++FourSchedOnln++" +S 0:0",
+ {Sched, SchedOnln, _} = get_sstate(Config, ResetCmd),
+ %% Test negative +S settings, but only for SMP-enabled emulators
+ case SmpSupport of
+ false -> ok;
+ true ->
+ SchedMinus1 = Sched-1,
+ SchedOnlnMinus1 = SchedOnln-1,
+ {SchedMinus1, SchedOnlnMinus1, _} = get_sstate(Config, "+S -1"),
+ {Sched, SchedOnlnMinus1, _} = get_sstate(Config, "+S :-1"),
+ {SchedMinus1, SchedOnlnMinus1, _} = get_sstate(Config, "+S -1:-1")
+ end,
+ ok.
+
+get_sstate(Config, Cmd) ->
+ {ok, Node} = start_node(Config, Cmd),
+ [SState] = mcall(Node, [fun () ->
+ erlang:system_info(schedulers_state)
+ end]),
+ stop_node(Node),
+ SState.
+
scheduler_suspend(Config) when is_list(Config) ->
?line Dog = ?t:timetrap(?t:minutes(5)),
?line lists:foreach(fun (S) -> scheduler_suspend_test(Config, S) end,
diff --git a/erts/etc/common/erlexec.c b/erts/etc/common/erlexec.c
index e61ebe15f5..552afe295d 100644
--- a/erts/etc/common/erlexec.c
+++ b/erts/etc/common/erlexec.c
@@ -803,7 +803,6 @@ int main(int argc, char **argv)
case 'n':
case 'P':
case 'Q':
- case 'S':
case 't':
case 'T':
case 'R':
@@ -818,6 +817,19 @@ int main(int argc, char **argv)
add_Eargs(argv[i+1]);
i++;
break;
+ case 'S':
+ if (argv[i][2] == 'P') {
+ if (argv[i][3] != '\0')
+ goto the_default;
+ } else if (argv[i][2] != '\0')
+ goto the_default;
+ if (i+1 >= argc)
+ usage(argv[i]);
+ argv[i][0] = '-';
+ add_Eargs(argv[i]);
+ add_Eargs(argv[i+1]);
+ i++;
+ break;
case 'B':
argv[i][0] = '-';
if (argv[i][2] != '\0') {
@@ -1119,7 +1131,9 @@ usage_aux(void)
"[+l] [+M<SUBSWITCH> <ARGUMENT>] [+P MAX_PROCS] [+Q MAX_PORTS] "
"[+R COMPAT_REL] "
"[+r] [+rg READER_GROUPS_LIMIT] [+s SCHEDULER_OPTION] "
- "[+S NO_SCHEDULERS:NO_SCHEDULERS_ONLINE] [+T LEVEL] [+V] [+v] "
+ "[+S NO_SCHEDULERS:NO_SCHEDULERS_ONLINE] "
+ "[+SP PERCENTAGE_SCHEDULERS:PERCENTAGE_SCHEDULERS_ONLINE] "
+ "[+T LEVEL] [+V] [+v] "
"[+W<i|w>] [+z MISC_OPTION] [args ...]\n");
exit(1);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 05:45:03 +0000