diff options
Diffstat (limited to 'erts/doc/src/erts_alloc.xml')
| -rw-r--r-- | erts/doc/src/erts_alloc.xml | 123 |
1 files changed, 84 insertions, 39 deletions
diff --git a/erts/doc/src/erts_alloc.xml b/erts/doc/src/erts_alloc.xml index 8ab35851c1..a094217959 100644 --- a/erts/doc/src/erts_alloc.xml +++ b/erts/doc/src/erts_alloc.xml @@ -4,7 +4,7 @@ <cref> <header> <copyright> - <year>2002</year><year>2016</year> + <year>2002</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -68,8 +68,7 @@ fixed size data types.</item> <tag><c>exec_alloc</c></tag> <item>Allocator used by the <seealso marker="hipe:HiPE_app"><c>HiPE</c></seealso> - application for native executable code on specific architectures - (x86_64).</item> + application for native executable code.</item> <tag><c>std_alloc</c></tag> <item>Allocator used for most memory blocks not allocated through any of the other allocators described above.</item> @@ -87,9 +86,9 @@ the number of system calls made.</item> </taglist> - <p><c>sys_alloc</c> and <c>literal_alloc</c> are always enabled and - cannot be disabled. <c>exec_alloc</c> is only available if it is needed - and cannot be disabled. <c>mseg_alloc</c> is always enabled if it is + <p><c>sys_alloc</c>, <c>literal_alloc</c> and <c>temp_alloc</c> are always + enabled and cannot be disabled. <c>exec_alloc</c> is only available if it + is needed and cannot be disabled. <c>mseg_alloc</c> is always enabled if it is available and an allocator that uses it is enabled. All other allocators can be <seealso marker="#M_e">enabled or disabled</seealso>. By default all allocators are enabled. @@ -225,6 +224,33 @@ used. The time complexity is proportional to log N, where N is the number of free blocks.</p> </item> + <tag>Age order first fit carrier address order first fit</tag> + <item> + <p>Strategy: Find the <em>oldest carrier</em> that + can satisfy the requested block size, then find a block within + that carrier using the "address order first fit" strategy.</p> + <p>Implementation: A balanced binary search tree is + used. The time complexity is proportional to log N, where + N is the number of free blocks.</p> + </item> + <tag>Age order first fit carrier best fit</tag> + <item> + <p>Strategy: Find the <em>oldest carrier</em> that + can satisfy the requested block size, then find a block within + that carrier using the "best fit" strategy.</p> + <p>Implementation: Balanced binary search trees are + used. The time complexity is proportional to log N, where + N is the number of free blocks.</p> + </item> + <tag>Age order first fit carrier address order best fit</tag> + <item> + <p>Strategy: Find the <em>oldest carrier</em> that + can satisfy the requested block size, then find a block within + that carrier using the "address order best fit" strategy.</p> + <p>Implementation: Balanced binary search trees are + used. The time complexity is proportional to log N, where + N is the number of free blocks.</p> + </item> <tag>Good fit</tag> <item> <p>Strategy: Try to find the best fit, but settle for the best fit @@ -452,7 +478,7 @@ utilization value > 0 is used, allocator instances are allowed to abandon multiblock carriers. If <c>de</c> (default enabled) is passed instead of a <c><![CDATA[<utilization>]]></c>, - a recomended non-zero utilization value is used. The value + a recommended non-zero utilization value is used. The value chosen depends on the allocator type and can be changed between ERTS versions. Defaults to <c>de</c>, but this can be changed in the future.</p> @@ -467,7 +493,8 @@ fetched, it will function as an ordinary carrier. This feature has special requirements on the <seealso marker="#M_as">allocation strategy</seealso> used. Only - the strategies <c>aoff</c>, <c>aoffcbf</c>, and <c>aoffcaobf</c> + the strategies <c>aoff</c>, <c>aoffcbf</c>, <c>aoffcaobf</c>, + <c>ageffcaoff</c>m, <c>ageffcbf</c> and <c>ageffcaobf</c> support abandoned carriers.</p> <p>This feature also requires <seealso marker="#M_t">multiple thread specific instances</seealso> @@ -478,8 +505,30 @@ allocators based on the <c>alloc_util</c> framework, except <c>temp_alloc</c> (which would be pointless).</p> </item> + + <tag><marker id="M_acfml"/><c><![CDATA[+M<S>acfml <bytes>]]></c> + </tag> + <item> + <p>Abandon carrier free block min limit. A valid <c><![CDATA[<bytes>]]></c> + is a positive integer representing a block size limit. The largest + free block in a carrier must be at least <c>bytes</c> large, for the + carrier to be abandoned. The default is zero but can be changed + in the future.</p> + <p>See also <seealso marker="#M_acul"><c>acul</c></seealso>.</p> + </item> + + <tag><marker id="M_acnl"/><c><![CDATA[+M<S>acnl <amount>]]></c> + </tag> + <item> + <p>Abandon carrier number limit. A valid <c><![CDATA[<amount>]]></c> + is a positive integer representing max number of abandoned carriers per + allocator instance. Defaults to 1000 which will practically disable + the limit, but this can be changed in the future.</p> + <p>See also <seealso marker="#M_acul"><c>acul</c></seealso>.</p> + </item> + <tag><marker id="M_as"/> - <c><![CDATA[+M<S>as bf|aobf|aoff|aoffcbf|aoffcaobf|gf|af]]></c></tag> + <c><![CDATA[+M<S>as bf|aobf|aoff|aoffcbf|aoffcaobf|ageffcaoff|ageffcbf|ageffcaobf|gf|af]]></c></tag> <item> <p>Allocation strategy. The following strategies are valid:</p> <list type="bulleted"> @@ -490,6 +539,11 @@ </item> <item><c>aoffcaobf</c> (address order first fit carrier address order best fit)</item> + <item><c>ageffcaoff</c> (age order first fit carrier address order first fit)</item> + <item><c>ageffcbf</c> (age order first fit carrier best fit) + </item> + <item><c>ageffcaobf</c> (age order first fit carrier address + order best fit)</item> <item><c>gf</c> (good fit)</item> <item><c>af</c> (a fit)</item> </list> @@ -505,6 +559,20 @@ than this threshold, otherwise the carrier is shrunk. See also <seealso marker="#M_rsbcst"><c>rsbcst</c></seealso>.</p> </item> + <tag><marker id="M_atags"/><c><![CDATA[+M<S>atags true|false]]></c></tag> + <item> + <p>Adds a small tag to each allocated block that contains basic + information about what it is and who allocated it. Use the + <seealso marker="tools:instrument"><c>instrument</c></seealso> + module to inspect this information.</p> + + <p>The runtime overhead is one word per allocation when enabled. This + may change at any time in the future.</p> + + <p>The default is <c>true</c> for <c>binary_alloc</c> and + <c>driver_alloc</c>, and <c>false</c> for the other allocator + types.</p> + </item> <tag><marker id="M_e"/><c><![CDATA[+M<S>e true|false]]></c></tag> <item> <p>Enables allocator <c><![CDATA[<S>]]></c>.</p> @@ -595,7 +663,7 @@ </item> <tag><marker id="M_sbct"/><c><![CDATA[+M<S>sbct <size>]]></c></tag> <item> - <p>Singleblock carrier threshold. Blocks larger than this + <p>Singleblock carrier threshold (in kilobytes). Blocks larger than this threshold are placed in singleblock carriers. Blocks smaller than this threshold are placed in multiblock carriers. On 32-bit Unix style OS this threshold cannot be set @@ -668,37 +736,14 @@ </section> <section> - <title>Special Flag for exec_alloc</title> - <taglist> - <tag><marker id="MXscs"/><c><![CDATA[+MXscs <size in MB>]]></c></tag> - <item> - <p><c>exec_alloc</c> super carrier size (in MB). The amount of - <em>virtual</em> address space reserved for native executable code - used by the <seealso marker="hipe:HiPE_app"><c>HiPE</c></seealso> application - on specific architectures (x86_64). Defaults to <c>512</c>.</p> - </item> - </taglist> - </section> - - <section> <title>Instrumentation Flags</title> <taglist> - <tag><marker id="Mim"/><c>+Mim true|false</c></tag> - <item> - <p>A map over current allocations is kept by the emulator. - The allocation map can be retrieved through module - <seealso marker="tools:instrument"> - <c>instrument(3)</c></seealso>. <c>+Mim true</c> - implies <c>+Mis true</c>. <c>+Mim true</c> is the same as flag - <seealso marker="erl#instr"><c>-instr</c></seealso> in - <c>erl(1)</c>.</p> - </item> - <tag><marker id="Mis"/><c>+Mis true|false</c></tag> - <item> - <p>Status over allocated memory is kept by the emulator. - The allocation status can be retrieved through module - <seealso marker="tools:instrument"> - <c>instrument(3)</c></seealso>.</p> + <tag><c>+M<S>atags</c></tag> + <item> + <p>Adds a small tag to each allocated block that contains basic + information about what it is and who allocated it. See + <seealso marker="#M_atags"><c>+M<S>atags</c></seealso> for a + more complete description.</p> </item> <tag><marker id="Mit"/><c>+Mit X</c></tag> <item> |