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-rw-r--r--erts/doc/src/erl.xml164
1 files changed, 94 insertions, 70 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 638e88ca31..4cf0066999 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -360,11 +360,12 @@
</item>
<tag><c><![CDATA[-mode interactive | embedded]]></c></tag>
<item>
- <p>Indicates if the system is to load code dynamically
- (<c><![CDATA[interactive]]></c>), or if all code is to be loaded
- during system initialization (<c><![CDATA[embedded]]></c>); see
- <seealso marker="kernel:code"><c>code(3)</c></seealso>.
- Defaults to <c><![CDATA[interactive]]></c>.</p>
+ <p>Modules are auto loaded when they are first referenced if the
+ runtime system runs in <c><![CDATA[interactive]]></c> mode, which is
+ the default. In <c><![CDATA[embedded]]></c> mode modules are not auto
+ loaded. The latter is recommended when the boot script preloads all
+ modules, as conventionally happens in OTP releases. See
+ <seealso marker="kernel:code"><c>code(3)</c></seealso></p>.
</item>
<tag><c><![CDATA[-name Name]]></c></tag>
<item>
@@ -538,20 +539,6 @@
<p>Note that a distributed node will fail to start if epmd is
not running.</p>
</item>
- <tag><marker id="smp"/><c><![CDATA[-smp [enable|auto|disable]]]></c></tag>
- <item>
- <p><c>-smp enable</c> and <c>-smp</c> start the Erlang runtime
- system with SMP support enabled. This can fail if no runtime
- system with SMP support is available. <c>-smp auto</c> starts
- the Erlang runtime system with SMP support enabled if it is
- available and more than one logical processor is detected.
- <c>-smp disable</c> starts a runtime system without SMP support.
- The runtime system without SMP support is deprecated and will
- be removed in a future major release.</p>
- <note>
- <p>See also flag<seealso marker="#+S"><c>+S</c></seealso>.</p>
- </note>
- </item>
<tag><c><![CDATA[-version]]></c> (emulator flag)</tag>
<item>
<p>Makes the emulator print its version number. The same
@@ -585,7 +572,7 @@
<tag><marker id="async_thread_pool_size"/><c><![CDATA[+A size]]></c></tag>
<item>
<p>Sets the number of threads in async thread pool. Valid range
- is 0-1024. Defaults to 10 if thread support is available.</p>
+ is 0-1024. Defaults to 1.</p>
</item>
<tag><c><![CDATA[+B [c | d | i]]]></c></tag>
<item>
@@ -644,14 +631,16 @@
of process heaps is destroyed by the crash dump generation.</p>
<p>Option <c>+d</c> instructs the emulator to produce only a
core dump and no crash dump if an internal error is detected.</p>
- <p>Calling <seealso marker="erlang:halt/1">
+ <p>Calling <seealso marker="erlang#halt/1">
<c>erlang:halt/1</c></seealso> with a string argument still
produces a crash dump. On Unix systems, sending an emulator process
a <c>SIGUSR1</c> signal also forces a crash dump.</p>
</item>
<tag><marker id="+e"/><c><![CDATA[+e Number]]></c></tag>
<item>
- <p>Sets the maximum number of ETS tables.</p>
+ <p>Sets the maximum number of ETS tables. This limit is
+ <seealso marker="stdlib:ets#max_ets_tables">partially obsolete</seealso>.
+ </p>
</item>
<tag><c><![CDATA[+ec]]></c></tag>
<item>
@@ -776,13 +765,40 @@
<seealso marker="erlang#process_flag_message_queue_data">
<c>process_flag(message_queue_data, MQD)</c></seealso>.</p>
</item>
- <tag><c><![CDATA[+K true | false]]></c></tag>
+ <tag><marker id="+IOp"/><c>+IOp PollSets</c></tag>
+ <item>
+ <p>Sets the number of IO pollsets to use when polling for I/O.
+ This option is only used on platforms that support concurrent
+ updates of a pollset, otherwise the same number of pollsets
+ are used as IO poll threads.
+ The default is 1.
+ </p>
+ </item>
+ <tag><marker id="+IOt"/><c>+IOt PollThreads</c></tag>
+ <item>
+ <p>Sets the number of IO poll threads to use when polling for I/O.
+ The maximum number of poll threads allowed is 1024. The default is 1.
+ </p>
+ <p>A good way to check if more IO poll threads are needed is to use
+ <seealso marker="runtime_tools:msacc">microstate accounting</seealso>
+ and see what the load of the IO poll thread is. If it is high it could
+ be a good idea to add more threads.</p>
+ </item>
+ <tag><marker id="+IOPp"/><c>+IOPp PollSetsPercentage</c></tag>
+ <item>
+ <p>Similar to <seealso marker="#+IOp"><c>+IOp</c></seealso> but uses
+ percentages to set the number of IO pollsets to create, based on the
+ number of poll threads configured. If both <c>+IOPp</c> and <c>+IOp</c>
+ are used, <c>+IOPp</c> is ignored.
+ </p>
+ </item>
+ <tag><marker id="+IOPt"/><c>+IOPt PollThreadsPercentage</c></tag>
<item>
- <p>Enables or disables the kernel poll functionality if supported by
- the emulator. Defaults to <c><![CDATA[false]]></c> (disabled).
- If the emulator does not support kernel poll, and flag
- <c><![CDATA[+K]]></c> is passed to the emulator, a warning is
- issued at startup.</p>
+ <p>Similar to <seealso marker="#+IOt"><c>+IOt</c></seealso> but uses
+ percentages to set the number of IO poll threads to create, based on
+ the number of schedulers configured. If both <c>+IOPt</c> and
+ <c>+IOt</c> are used, <c>+IOPt</c> is ignored.
+ </p>
</item>
<tag><c><![CDATA[+l]]></c></tag>
<item>
@@ -902,7 +918,7 @@
<c><![CDATA[+S Schedulers:SchedulerOnline]]></c></tag>
<item>
<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
+ to set online. The maximum for both
values is 1024. If the Erlang runtime system is able to determine the
number of logical processors configured and logical processors
available, <c>Schedulers</c> defaults to logical processors
@@ -920,8 +936,6 @@
<p>Specifying value <c>0</c> 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 does not have SMP support
- enabled (see flag <seealso marker="#smp"><c>-smp</c></seealso>).</p>
</item>
<tag><marker id="+SP"/><c><![CDATA[+SP
SchedulersPercentage:SchedulersOnlinePercentage]]></c></tag>
@@ -929,8 +943,8 @@
<p>Similar to <seealso marker="#+S"><c>+S</c></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 &gt; 0. For example,
+ based on logical processors available.
+ Specified values must be &gt; 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.
@@ -945,15 +959,13 @@
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 does not have SMP support
- enabled (see flag <seealso marker="#smp"><c>-smp</c></seealso>).</p>
</item>
<tag><marker id="+SDcpu"/><c><![CDATA[+SDcpu
DirtyCPUSchedulers:DirtyCPUSchedulersOnline]]></c></tag>
<item>
<p>Sets the number of dirty CPU scheduler threads to create and dirty
- CPU scheduler threads to set online when threading support has been
- enabled. The maximum for both values is 1024, and each value is
+ CPU scheduler threads to set online.
+ The maximum for both values is 1024, and each value is
further limited by the settings for normal schedulers:</p>
<list type="bulleted">
<item>The number of dirty CPU scheduler threads created cannot exceed
@@ -977,16 +989,14 @@
executing on ordinary schedulers. If the amount of dirty CPU
schedulers was allowed to be unlimited, dirty CPU bound jobs would
potentially starve normal jobs.</p>
- <p>This option is ignored if the emulator does not have threading
- support enabled.</p>
</item>
<tag><marker id="+SDPcpu"/><c><![CDATA[+SDPcpu
DirtyCPUSchedulersPercentage:DirtyCPUSchedulersOnlinePercentage]]></c></tag>
<item>
<p>Similar to <seealso marker="#+SDcpu"><c>+SDcpu</c></seealso> but
uses percentages to set the number of dirty CPU scheduler threads to
- create and the number of dirty CPU scheduler threads to set online
- when threading support has been enabled. Specified values must be
+ create and the number of dirty CPU scheduler threads to set online.
+ Specified values must be
&gt; 0. For example, <c>+SDPcpu 50:25</c> sets the number of dirty
CPU scheduler threads to 50% of the logical processors configured
and the number of dirty CPU scheduler threads online to 25% of the
@@ -1003,13 +1013,11 @@
the combination of the options <c>+SDcpu 4:4 +SDPcpu 50:25</c> (in
either order) results in 2 dirty CPU scheduler threads (50% of 4) and
1 dirty CPU scheduler thread online (25% of 4).</p>
- <p>This option is ignored if the emulator does not have threading
- support enabled.</p>
</item>
<tag><marker id="+SDio"/><c><![CDATA[+SDio DirtyIOSchedulers]]></c></tag>
<item>
- <p>Sets the number of dirty I/O scheduler threads to create when
- threading support has been enabled. Valid range is 0-1024. By
+ <p>Sets the number of dirty I/O scheduler threads to create.
+ Valid range is 0-1024. By
default, the number of dirty I/O scheduler threads created is 10,
same as the default number of threads in the <seealso
marker="#async_thread_pool_size">async thread pool</seealso>.</p>
@@ -1019,8 +1027,6 @@
expected to execute on dirty I/O schedulers. If the user should schedule CPU
bound jobs on dirty I/O schedulers, these jobs might starve ordinary
jobs executing on ordinary schedulers.</p>
- <p>This option is ignored if the emulator does not have threading
- support enabled.</p>
</item>
<tag><c><![CDATA[+sFlag Value]]></c></tag>
<item>
@@ -1151,6 +1157,26 @@
without prior notice.</p>
</note>
</item>
+ <tag><marker id="+sbwtdcpu"/>
+ <c>+sbwtdcpu none|very_short|short|medium|long|very_long</c></tag>
+ <item>
+ <p>As <seealso marker="#+sbwt"><c>+sbwt</c></seealso> but affects
+ dirty CPU schedulers. Defaults to <c>short</c>.</p>
+ <note>
+ <p>This flag can be removed or changed at any time
+ without prior notice.</p>
+ </note>
+ </item>
+ <tag><marker id="+sbwtdio"/>
+ <c>+sbwtdio none|very_short|short|medium|long|very_long</c></tag>
+ <item>
+ <p>As <seealso marker="#+sbwt"><c>+sbwt</c></seealso> but affects
+ dirty IO schedulers. Defaults to <c>short</c>.</p>
+ <note>
+ <p>This flag can be removed or changed at any time
+ without prior notice.</p>
+ </note>
+ </item>
<tag><marker id="+scl"/><c>+scl true|false</c></tag>
<item>
<p>Enables or disables scheduler compaction of load. By default
@@ -1297,25 +1323,6 @@
<seealso marker="erlang#system_info_cpu_topology">
<c>erlang:system_info(cpu_topology)</c></seealso>.</p>
</item>
- <tag><marker id="+secio"/><c>+secio true|false</c></tag>
- <item>
- <p>Enables or disables eager check I/O scheduling. Defaults
- to <c>true</c>. The default was changed from <c>false</c>
- as from ERTS 7.0. The behavior before this
- flag was introduced corresponds to <c>+secio false</c>.</p>
- <p>The flag effects when schedulers will check for I/O
- operations possible to execute, and when such I/O operations
- will execute. As the parameter name implies,
- schedulers are more eager to check for I/O when
- <c>true</c> is passed. This, however, also implies that
- execution of outstanding I/O operation is not
- prioritized to the same extent as when <c>false</c> is
- passed.</p>
- <p><seealso marker="erlang#system_info_eager_check_io">
- <c>erlang:system_info(eager_check_io)</c></seealso>
- returns the value of this parameter used when starting
- the virtual machine.</p>
- </item>
<tag><marker id="+sfwi"/><c>+sfwi Interval</c></tag>
<item>
<p>Sets scheduler-forced wakeup interval. All run queues are
@@ -1435,6 +1442,26 @@
notice.</p>
</note>
</item>
+ <tag><marker id="+swtdcpu"/>
+ <c>+swtdcpu very_low|low|medium|high|very_high</c></tag>
+ <item>
+ <p>As <seealso marker="#+swt"><c>+swt</c></seealso> but
+ affects dirty CPU schedulers. Defaults to <c>medium</c>.</p>
+ <note>
+ <p>This flag can be removed or changed at any time
+ without prior notice.</p>
+ </note>
+ </item>
+ <tag><marker id="+swtdio"/>
+ <c>+swtdio very_low|low|medium|high|very_high</c></tag>
+ <item>
+ <p>As <seealso marker="#+swt"><c>+swt</c></seealso> but affects
+ dirty IO schedulers. Defaults to <c>medium</c>.</p>
+ <note>
+ <p>This flag can be removed or changed at any time
+ without prior notice.</p>
+ </note>
+ </item>
</taglist>
</item>
<tag><marker id="+t"/><c><![CDATA[+t size]]></c></tag>
@@ -1657,9 +1684,7 @@
<tag>The <c>.erlang</c> startup file</tag>
<item>
<p>When Erlang/OTP is started, the system searches for a file named
- <c>.erlang</c> in the directory where Erlang/OTP is started. If not
- found, the user's home directory is searched for an <c>.erlang</c>
- file.</p>
+ <c>.erlang</c> in the user's home directory.</p>
<p>If an <c>.erlang</c> file is found, it is assumed to contain valid
Erlang expressions. These expressions are evaluated as if they were
input to the shell.</p>
@@ -1711,4 +1736,3 @@ code:load_abs("..../user_default"). ]]></code>
<seealso marker="tools:make"><c>make(3)</c></seealso></p>
</section>
</comref>
-