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-rw-r--r--erts/doc/src/erl.xml111
1 files changed, 97 insertions, 14 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 528a2d95aa..4aa3033f40 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="latin1" ?>
+<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE comref SYSTEM "comref.dtd">
<comref>
@@ -535,12 +535,15 @@
</item>
<tag><marker id="file_name_encoding"></marker><c><![CDATA[+fnl]]></c></tag>
<item>
- <p>The VM works with file names as if they are encoded using the ISO-latin-1 encoding, disallowing Unicode characters with codepoints beyond 255. This is default on operating systems that have transparent file naming, i.e. all Unixes except MacOSX.</p>
+ <p>The VM works with file names as if they are encoded using the ISO-latin-1 encoding, disallowing Unicode characters with codepoints beyond 255.</p>
<p>See <seealso marker="stdlib:unicode_usage#unicode_file_names">STDLIB User's Guide</seealso> for more infomation about unicode file names.</p>
</item>
<tag><c><![CDATA[+fnu[{w|i|e}]]]></c></tag>
<item>
- <p>The VM works with file names as if they are encoded using UTF-8 (or some other system specific Unicode encoding). This is the default on operating systems that enforce Unicode encoding, i.e. Windows and MacOSX.</p>
+ <p>The VM works with file names as if they are encoded using
+ UTF-8 (or some other system specific Unicode encoding). This
+ is the default on operating systems that enforce Unicode
+ encoding, i.e. Windows and MacOS X.</p>
<p>The <c>+fnu</c> switch can be followed by <c>w</c>,
<c>i</c>, or <c>e</c> to control the way wrongly encoded file
names are to be reported. <c>w</c> means that a warning is
@@ -556,7 +559,12 @@
</item>
<tag><c><![CDATA[+fna[{w|i|e}]]]></c></tag>
<item>
- <p>Selection between <c>+fnl</c> and <c>+fnu</c> is done based on the current locale settings in the OS, meaning that if you have set your terminal for UTF-8 encoding, the filesystem is expected to use the same encoding for file names (use with care).</p>
+ <p>Selection between <c>+fnl</c> and <c>+fnu</c> is done based
+ on the current locale settings in the OS, meaning that if you
+ have set your terminal for UTF-8 encoding, the filesystem is
+ expected to use the same encoding for file names. This is
+ default on all operating systems except MacOS X and
+ Windows.</p>
<p>The <c>+fna</c> switch can be followed by <c>w</c>,
<c>i</c>, or <c>e</c>. This will have effect if the locale
settings cause the behavior of <c>+fnu</c> to be selected.
@@ -792,6 +800,54 @@
SMP support enabled (see the <seealso marker="#smp">-smp</seealso>
flag).</p>
</item>
+ <tag><marker id="+SDcpu"><c><![CDATA[+SDcpu DirtyCPUSchedulers:DirtyCPUSchedulersOnline]]></c></marker></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 further
+ limited by the settings for normal schedulers: the number of dirty CPU
+ scheduler threads created cannot exceed the number of normal scheduler
+ threads created, and the number of dirty CPU scheduler threads online
+ cannot exceed the number of normal scheduler threads online (see the
+ <seealso marker="#+S">+S</seealso> and <seealso marker="#+SP">+SP</seealso>
+ flags for more details). By default, the number of dirty CPU scheduler
+ threads created equals the number of normal scheduler threads created,
+ and the number of dirty CPU scheduler threads online equals the number
+ of normal scheduler threads online. <c>DirtyCPUSchedulers</c> may be
+ omitted if <c>:DirtyCPUSchedulersOnline</c> is not and vice versa. The
+ number of dirty CPU schedulers online can be changed at run time via
+ <seealso marker="erlang#system_flag_dirty_cpu_schedulers_online">erlang:system_flag(dirty_cpu_schedulers_online, DirtyCPUSchedulersOnline)</seealso>.
+ </p>
+ <p>This option is ignored if the emulator doesn't have threading support
+ enabled. Currently, <em>this option is experimental</em> and is supported only
+ if the emulator was configured and built with support for dirty schedulers
+ enabled (it's disabled by default).
+ </p>
+ </item>
+ <tag><marker id="+SDPcpu"><c><![CDATA[+SDPcpu DirtyCPUSchedulersPercentage:DirtyCPUSchedulersOnlinePercentage]]></c></marker></tag>
+ <item>
+ <p>Similar to <seealso marker="#+SDcpu">+SDcpu</seealso> but uses percentages to set the
+ number of dirty CPU scheduler threads to create and number of dirty CPU scheduler threads
+ to set online when threading support has been enabled. Specified values must be greater
+ than 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 logical processors available. <c>DirtyCPUSchedulersPercentage</c> may
+ be omitted if <c>:DirtyCPUSchedulersOnlinePercentage</c> is not and vice versa. The
+ number of dirty CPU schedulers online can be changed at run time via
+ <seealso marker="erlang#system_flag_dirty_cpu_schedulers_online">erlang:system_flag(dirty_cpu_schedulers_online, DirtyCPUSchedulersOnline)</seealso>.
+ </p>
+ <p>This option interacts with <seealso marker="#+SDcpu">+SDcpu</seealso> settings.
+ For example, on a system with 8 logical cores configured and 8 logical cores available,
+ 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 doesn't have threading support
+ enabled. Currently, <em>this option is experimental</em> and is supported only
+ if the emulator was configured and built with support for dirty schedulers
+ enabled (it's disabled by default).
+ </p>
+ </item>
+ <tag><marker id="+SDio"><c><![CDATA[+SDio IOSchedulers]]></c></marker></tag>
<tag><c><![CDATA[+sFlag Value]]></c></tag>
<item>
<p>Scheduling specific flags.</p>
@@ -941,6 +997,10 @@
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.
+ <br/>&nbsp;&nbsp;<c>+scl false</c> is similar to
+ <seealso marker="#+sub">+sub true</seealso> with the difference
+ that <c>+sub true</c> also will balance scheduler utilization
+ between schedulers.
</p>
</item>
<tag><marker id="+sct"><c>+sct CpuTopology</c></marker></tag>
@@ -1087,6 +1147,29 @@
documentation of the <seealso marker="#+sbt">+sbt</seealso> flag.
</p>
</item>
+ <tag><marker id="+sub"><c>+sub true|false</c></marker></tag>
+ <item>
+ <p>Enable or disable
+ <seealso marker="erts:erlang#statistics_scheduler_wall_time">scheduler
+ utilization</seealso> balancing of load. By default scheduler
+ utilization balancing is disabled and instead scheduler
+ compaction of load is enabled which 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). When scheduler
+ utilization balancing is enabled the system will instead try to
+ balance scheduler utilization between schedulers. That is,
+ strive for equal scheduler utilization on all schedulers.
+ <br/>&nbsp;&nbsp;&nbsp;<c>+sub true</c> is only supported on
+ systems where the runtime system detects and use a monotonically
+ increasing high resolution clock. On other systems, the runtime
+ system will fail to start.
+ <br/>&nbsp;&nbsp;&nbsp;<c>+sub true</c> implies
+ <seealso marker="#+scl">+scl false</seealso>. The difference
+ between <c>+sub true</c> and <c>+scl false</c> is that
+ <c>+scl false</c> will not try to balance the scheduler
+ utilization.
+ </p>
+ </item>
<tag><marker id="+swct"><c>+sws very_eager|eager|medium|lazy|very_lazy</c></marker></tag>
<item>
<p>
@@ -1126,18 +1209,18 @@
<tag><marker id="+spp"><c>+spp Bool</c></marker></tag>
<item>
<p>Set default scheduler hint for port parallelism. If set to
- <c>true</c>, the VM will schedule port tasks when it by this can
- improve the parallelism in the system. If set to <c>false</c>,
- the VM will try to perform port tasks immediately and by this
- improve latency at the expense of parallelism. If this
- flag has not been passed, the default scheduler hint for port
- parallelism is currently <c>false</c>. The default used can be
- inspected in runtime by calling
- <seealso marker="erlang#system_info_port_parallelism">erlang:system_info(port_parallelism)</seealso>.
+ <c>true</c>, the VM will schedule port tasks when doing so will
+ improve parallelism in the system. If set to <c>false</c>, the VM
+ will try to perform port tasks immediately, improving latency at the
+ expense of parallelism. If this flag has not been passed, the
+ default scheduler hint for port parallelism is currently
+ <c>false</c>. The default used can be inspected in runtime by
+ calling <seealso
+ marker="erlang#system_info_port_parallelism">erlang:system_info(port_parallelism)</seealso>.
The default can be overriden on port creation by passing the
<seealso marker="erlang#open_port_parallelism">parallelism</seealso>
- option to
- <seealso marker="erlang#open_port/2">open_port/2</seealso></p>.
+ option to <seealso
+ marker="erlang#open_port/2">open_port/2</seealso></p>.
</item>
<tag><marker id="sched_thread_stack_size"><c><![CDATA[+sss size]]></c></marker></tag>
<item>