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-rw-r--r--erts/doc/src/erts_alloc.xml55
1 files changed, 41 insertions, 14 deletions
diff --git a/erts/doc/src/erts_alloc.xml b/erts/doc/src/erts_alloc.xml
index 8dd9ed1398..fffa9f594c 100644
--- a/erts/doc/src/erts_alloc.xml
+++ b/erts/doc/src/erts_alloc.xml
@@ -271,22 +271,18 @@
memory segment cache is not reused if its size exceeds the
requested size with more than relative max cache bad fit
percent of the requested size. Default value is 20.</item>
- <tag><marker id="MMscmgc"><c><![CDATA[+MMscmgc <amount>]]></c></marker></tag>
- <item>
- Set <seealso marker="#MMscs">super carrier</seealso> max guaranteed
- no of carriers. This parameter defaults to <c>65536</c>. This
- parameter determines an amount of pre-allocated structures that is
- needed in order to keep track of different areas in the super carrier.
- When the system runs out of such structures it may crash due to an
- out of memory condition.
- </item>
<tag><marker id="MMsco"><c><![CDATA[+MMsco true|false]]></c></marker></tag>
<item>
Set <seealso marker="#MMscs">super carrier</seealso> only flag. This
flag defaults to <c>true</c>. When a super carrier is used and this
- flag is <c>true</c>, the system will crash when a carrier request
- cannot be satisfied by the super carrier. When the flag is <c>false</c>
- the system will try to create requested carrier by other means.
+ flag is <c>true</c>, <c>mseg_alloc</c> will only create carriers
+ in the super carrier. Note that the <c>alloc_util</c> framework may
+ create <c>sys_alloc</c> carriers, so if you want all carriers to
+ be created in the super carrier, you therefore want to disable use
+ of <c>sys_alloc</c> carriers by also passing
+ <seealso marker="#Musac"><c>+Musac false</c></seealso>. When the flag
+ is <c>false</c>, <c>mseg_alloc</c> will try to create carriers outside
+ of the super carrier when the super carrier is full.
<br/><br/>
<em>NOTE</em>: Setting this flag to <c>false</c> may not be supported
on all systems. This flag will in that case be ignored.
@@ -295,6 +291,19 @@
disabled on halfword heap systems. This flag will be
ignored on halfword heap systems.
</item>
+ <tag><marker id="MMscrfsd"><c><![CDATA[+MMscrfsd <amount>]]></c></marker></tag>
+ <item>
+ Set <seealso marker="#MMscs">super carrier</seealso> reserved
+ free segment descriptors. This parameter defaults to <c>65536</c>.
+ This parameter determines the amount of memory to reserve for
+ free segment descriptors used by the super carrier. If the system
+ runs out of reserved memory for free segment descriptors, other
+ memory will be used. This may however cause fragmentation issues,
+ so you want to ensure that this never happens. The maximum amount
+ of free segment descriptors used can be retrieved from the
+ <c>erts_mmap</c> tuple part of the result from calling
+ <seealso marker="erts:erlang#system_info_allocator_tuple">erlang:system_info({allocator, mseg_alloc})</seealso>.
+ </item>
<tag><marker id="MMscrpm"><c><![CDATA[+MMscrpm true|false]]></c></marker></tag>
<item>
Set <seealso marker="#MMscs">super carrier</seealso> reserve physical
@@ -323,8 +332,11 @@
Set super carrier size (in MB). The super carrier size defaults to
zero; i.e, the super carrier is by default disabled. The super
carrier is a large continuous area in the virtual address space.
- The system will always try to create new carriers in the super
- carrier.
+ <c>mseg_alloc</c> will always try to create new carriers in the super
+ carrier if it exists. Note that the <c>alloc_util</c> framework may
+ create <c>sys_alloc</c> carriers. For more information on this, see the
+ documentation of the <seealso marker="#MMsco"><c>+MMsco</c></seealso>
+ flag.
<br/><br/>
<em>NOTE</em>: The super carrier cannot be enabled nor
disabled on halfword heap systems. This flag will be
@@ -549,6 +561,11 @@
placed in separate memory segments. When this limit has been
reached, new carriers will be placed in memory retrieved from
<c>sys_alloc</c>.</item>
+ <tag><marker id="Musac"><c><![CDATA[+Musac <bool>]]></c></marker></tag>
+ <item>
+ Allow <c>sys_alloc</c> carriers. By default <c>true</c>. If
+ set to <c>false</c>, <c>sys_alloc</c> carriers will never be
+ created by allocators using the <c>alloc_util</c> framework.</item>
</taglist>
<p>Instrumentation flags:</p>
<taglist>
@@ -604,6 +621,16 @@
</item>
</taglist>
</item>
+ <tag><marker id="Mlpm"><c>+Mlpm all|no</c></marker></tag>
+ <item>Lock physical memory. The default value is <c>no</c>, i.e.,
+ no physical memory will be locked. If set to <c>all</c>, all
+ memory mappings made by the runtime system, will be locked into
+ physical memory. If set to <c>all</c>, the runtime system will fail
+ to start if this feature is not supported, the user has not got enough
+ privileges, or the user is not allowed to lock enough physical memory.
+ The runtime system will also fail with an out of memory condition
+ if the user limit on the amount of locked memory is reached.
+ </item>
</taglist>
<p>Only some default values have been presented
here.