erts: Document the +M<S>acul command line argument

1 files changed, 31 insertions, 0 deletions

diff --git a/erts/doc/src/erts_alloc.xml b/erts/doc/src/erts_alloc.xml
index f79241d692..2ffb55c6ab 100644
--- a/erts/doc/src/erts_alloc.xml
+++ b/erts/doc/src/erts_alloc.xml
@@ -309,6 +309,37 @@
        subsystem identifier, only the specific allocator identified will be
        effected:</p>
     <taglist>
+      <tag><marker id="M_acul"><c><![CDATA[+M<S>acul <utilization>|de]]></c></marker></tag>
+      <item>
+	Abandon carrier utilization limit. A valid
+	<c><![CDATA[<utilization>]]></c> is an integer in the range
+	<c>[0, 100]</c> representing utilization in percent. When a
+	utilization value larger than zero is used, allocator instances
+	are allowed to abandon multiblock carriers. Currently the default
+	is zero. If <c>de</c> (default enabled) is passed instead of a
+	<c><![CDATA[<utilization>]]></c>, a recomended non zero utilization
+	value will be used. The actual value chosen depend on allocator
+	type and may be changed between ERTS versions. Carriers will be
+	abandoned when memory utilization in the allocator instance falls
+	below the utilization value used. Once a carrier has been abandoned,
+	no new allocations will be made in it. When an allocator instance
+	gets an increased multiblock carrier need, it will first try to
+	fetch an abandoned carrier from an allocator instances of the same
+	allocator type. If no abandoned carrier could be fetched, it will
+	create a new empty carrier. When an abandoned carrier has been
+	fetched it will function as an ordinary carrier. This feature has
+	special requirements on the
+	<seealso marker="#M_as">allocation strategy</seealso> used. Currently
+	only the <c>aoff</c> and the <c>aoffcaobf</c> strategies support
+	abandoned carriers. This feature also requires
+	<seealso marker="#M_t">multiple thread specific instances</seealso>
+	to be enabled. When enabling this feature, multiple thread specific
+	instances will be enabled if not already enabled, and the
+	<c>aoffcaobf</c> strategy will be enabled if current strategy does not
+	support abandoned carriers. This feature can be enabled on all
+	allocators based on the <c>alloc_util</c> framework with the
+	exception of <c>temp_alloc</c> (which would be pointless).
+      </item>
       <tag><marker id="M_as"><c><![CDATA[+M<S>as bf|aobf|aoff|aoffcaobf|gf|af]]></c></marker></tag>
       <item>
        Allocation strategy. Valid strategies are <c>bf</c> (best fit),