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authorRickard Green <[email protected]>2010-08-16 19:38:33 +0200
committerRickard Green <[email protected]>2010-08-18 18:00:34 +0200
commit1b273b618002d65159453fdfb9520a9476e4423a (patch)
tree1bb787ea400e726e575237274e347bd928787e84 /erts/doc/src/erlang.xml
parentbdfd2aaa1d402b3dd393a7820432f8f76e248ee1 (diff)
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Make it possible to reread and update detected CPU information
Calling erlang:system_info/1 with the new argument 'update_cpu_info' will make the runtime system reread and update the internally stored CPU information. For more information see the documentation of erlang:system_info(update_cpu_info).
Diffstat (limited to 'erts/doc/src/erlang.xml')
-rw-r--r--erts/doc/src/erlang.xml55
1 files changed, 49 insertions, 6 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 54a0a80536..cb3112acfe 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -5533,7 +5533,7 @@ true</pre>
<c>CpuTopology</c> type to change.
</p>
</item>
- <tag><c>{cpu_topology, defined}</c></tag>
+ <tag><marker id="system_info_cpu_topology_defined"><c>{cpu_topology, defined}</c></marker></tag>
<item>
<p>Returns the user defined <c>CpuTopology</c>. For more
information see the documentation of
@@ -5543,7 +5543,7 @@ true</pre>
argument.
</p>
</item>
- <tag><c>{cpu_topology, detected}</c></tag>
+ <tag><marker id="system_info_cpu_topology_detected"><c>{cpu_topology, detected}</c></marker></tag>
<item>
<p>Returns the automatically detected <c>CpuTopology</c>. The
emulator currently only detects the CPU topology on some newer
@@ -5727,11 +5727,34 @@ true</pre>
information see the <seealso marker="erts:crash_dump">"How to interpret the Erlang crash dumps"</seealso> chapter
in the ERTS User's Guide.</p>
</item>
- <tag><c>logical_processors</c></tag>
+ <tag><marker id="logical_processors"><c>logical_processors</c></marker></tag>
<item>
- <p>Returns the number of logical processors detected on the
- system as an integer or the atom <c>unknown</c> if the
- emulator wasn't able to detect any.
+ <p>Returns the detected number of logical processors configured
+ on the system. The return value is either an integer, or
+ the atom <c>unknown</c> if the emulator wasn't able to
+ detect logical processors configured.
+ </p>
+ </item>
+ <tag><marker id="logical_processors_available"><c>logical_processors_available</c></marker></tag>
+ <item>
+ <p>Returns the detected number of logical processors available to
+ the Erlang runtime system. The return value is either an
+ integer, or the atom <c>unknown</c> if the emulator wasn't
+ able to detect logical processors available. The number
+ of logical processors available is less than or equal to
+ the number of <seealso marker="#logical_processors_online">logical
+ processors online</seealso>.
+ </p>
+ </item>
+ <tag><marker id="logical_processors_online"><c>logical_processors_online</c></marker></tag>
+ <item>
+ <p>Returns the detected number of logical processors online on
+ the system. The return value is either an integer,
+ or the atom <c>unknown</c> if the emulator wasn't able to
+ detect logical processors online. The number of logical
+ processors online is less than or equal to the number of
+ <seealso marker="#logical_processors">logical processors
+ configured</seealso>.
</p>
</item>
<tag><c>machine</c></tag>
@@ -5936,6 +5959,26 @@ true</pre>
<c>get_tcw</c> in "Match Specifications in Erlang",
<seealso marker="erts:match_spec#get_tcw">ERTS User's Guide</seealso>.</p>
</item>
+ <tag><marker id="update_cpu_info"><c>update_cpu_info</c></marker></tag>
+ <item>
+ <p>The runtime system rereads the CPU information available and
+ updates its internally stored information about the
+ <seealso marker="#system_info_cpu_topology_detected">detected CPU
+ topology</seealso> and the amount of logical processors
+ <seealso marker="#logical_processors">configured</seealso>,
+ <seealso marker="#logical_processors_online">online</seealso>, and
+ <seealso marker="#logical_processors_available">available</seealso>.
+ If the CPU information has changed since the last time it was read,
+ the atom <c>changed</c> is returned; otherwise, the atom
+ <c>unchanged</c> is returned. If the CPU information has changed
+ you probably want to
+ <seealso marker="#system_flag_schedulers_online">adjust the amount
+ of schedulers online</seealso>. You typically want to have as
+ many schedulers online as
+ <seealso marker="#logical_processors_available">logical processors
+ available</seealso>.
+ </p>
+ </item>
<tag><marker id="system_info_version"><c>version</c></marker></tag>
<item>
<p>Returns a string containing the version number of the