<refname>malloc</refname>
<refname>calloc</refname>
<refname>posix_memalign</refname>
+ <refname>aligned_alloc</refname>
<refname>realloc</refname>
<refname>free</refname>
<refname>malloc_usable_size</refname>
<refname>rallocm</refname>
<refname>sallocm</refname>
<refname>dallocm</refname>
+ <refname>nallocm</refname>
-->
<refpurpose>general purpose memory allocation functions</refpurpose>
</refnamediv>
<paramdef>size_t <parameter>alignment</parameter></paramdef>
<paramdef>size_t <parameter>size</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>void *<function>aligned_alloc</function></funcdef>
+ <paramdef>size_t <parameter>alignment</parameter></paramdef>
+ <paramdef>size_t <parameter>size</parameter></paramdef>
+ </funcprototype>
<funcprototype>
<funcdef>void *<function>realloc</function></funcdef>
<paramdef>void *<parameter>ptr</parameter></paramdef>
<paramdef>void *<parameter>ptr</parameter></paramdef>
<paramdef>int <parameter>flags</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>int <function>nallocm</function></funcdef>
+ <paramdef>size_t *<parameter>rsize</parameter></paramdef>
+ <paramdef>size_t <parameter>size</parameter></paramdef>
+ <paramdef>int <parameter>flags</parameter></paramdef>
+ </funcprototype>
</refsect2>
</funcsynopsis>
</refsynopsisdiv>
<parameter>alignment</parameter> must be a power of 2 at least as large
as <code language="C">sizeof(<type>void *</type>)</code>.</para>
+ <para>The <function>aligned_alloc<parameter/></function> function
+ allocates <parameter>size</parameter> bytes of memory such that the
+ allocation's base address is an even multiple of
+ <parameter>alignment</parameter>. The requested
+ <parameter>alignment</parameter> must be a power of 2. Behavior is
+ undefined if <parameter>size</parameter> is not an integral multiple of
+ <parameter>alignment</parameter>.</para>
+
<para>The <function>realloc<parameter/></function> function changes the
size of the previously allocated memory referenced by
<parameter>ptr</parameter> to <parameter>size</parameter> bytes. The
<refsect2>
<title>Experimental API</title>
<para>The experimental API is subject to change or removal without regard
- for backward compatibility.</para>
+ for backward compatibility. If <option>--disable-experimental</option>
+ is specified during configuration, the experimental API is
+ omitted.</para>
<para>The <function>allocm<parameter/></function>,
<function>rallocm<parameter/></function>,
- <function>sallocm<parameter/></function>, and
- <function>dallocm<parameter/></function> functions all have a
+ <function>sallocm<parameter/></function>,
+ <function>dallocm<parameter/></function>, and
+ <function>nallocm<parameter/></function> functions all have a
<parameter>flags</parameter> argument that can be used to specify
options. The functions only check the options that are contextually
relevant. Use bitwise or (<code language="C">|</code>) operations to
least <parameter>size</parameter> bytes of memory, sets
<parameter>*ptr</parameter> to the base address of the allocation, and
sets <parameter>*rsize</parameter> to the real size of the allocation if
- <parameter>rsize</parameter> is not <constant>NULL</constant>.</para>
+ <parameter>rsize</parameter> is not <constant>NULL</constant>. Behavior
+ is undefined if <parameter>size</parameter> is
+ <constant>0</constant>.</para>
<para>The <function>rallocm<parameter/></function> function resizes the
allocation at <parameter>*ptr</parameter> to be at least
language="C"><parameter>size</parameter> +
<parameter>extra</parameter>)</code> bytes, though inability to allocate
the extra byte(s) will not by itself result in failure. Behavior is
- undefined if <code language="C">(<parameter>size</parameter> +
+ undefined if <parameter>size</parameter> is <constant>0</constant>, or if
+ <code language="C">(<parameter>size</parameter> +
<parameter>extra</parameter> >
<constant>SIZE_T_MAX</constant>)</code>.</para>
<para>The <function>dallocm<parameter/></function> function causes the
memory referenced by <parameter>ptr</parameter> to be made available for
future allocations.</para>
+
+ <para>The <function>nallocm<parameter/></function> function allocates no
+ memory, but it performs the same size computation as the
+ <function>allocm<parameter/></function> function, and if
+ <parameter>rsize</parameter> is not <constant>NULL</constant> it sets
+ <parameter>*rsize</parameter> to the real size of the allocation that
+ would result from the equivalent <function>allocm<parameter/></function>
+ function call. Behavior is undefined if
+ <parameter>size</parameter> is <constant>0</constant>.</para>
</refsect2>
</refsect1>
<refsect1 id="tuning">
suboptimal for several reasons, including race conditions, increased
fragmentation, and artificial limitations on maximum usable memory. If
<option>--enable-dss</option> is specified during configuration, this
- allocator uses both <citerefentry><refentrytitle>sbrk</refentrytitle>
+ allocator uses both <citerefentry><refentrytitle>mmap</refentrytitle>
<manvolnum>2</manvolnum></citerefentry> and
- <citerefentry><refentrytitle>mmap</refentrytitle>
+ <citerefentry><refentrytitle>sbrk</refentrytitle>
<manvolnum>2</manvolnum></citerefentry>, in that order of preference;
otherwise only <citerefentry><refentrytitle>mmap</refentrytitle>
<manvolnum>2</manvolnum></citerefentry> is used.</para>
allocations in constant time.</para>
<para>Small objects are managed in groups by page runs. Each run maintains
- a frontier and free list to track which regions are in use. Unless
- <option>--disable-tiny</option> is specified during configuration,
- allocation requests that are no more than half the quantum (8 or 16,
- depending on architecture) are rounded up to the nearest power of two that
- is at least <code language="C">sizeof(<type>void *</type>)</code>.
- Allocation requests that are more than half the quantum, but no more than
- the minimum cacheline-multiple size class (see the <link
- linkend="opt.lg_qspace_max"><mallctl>opt.lg_qspace_max</mallctl></link>
- option) are rounded up to the nearest multiple of the quantum. Allocation
- requests that are more than the minimum cacheline-multiple size class, but
- no more than the minimum subpage-multiple size class (see the <link
- linkend="opt.lg_cspace_max"><mallctl>opt.lg_cspace_max</mallctl></link>
- option) are rounded up to the nearest multiple of the cacheline size (64).
- Allocation requests that are more than the minimum subpage-multiple size
- class, but no more than the maximum subpage-multiple size class are rounded
- up to the nearest multiple of the subpage size (256). Allocation requests
- that are more than the maximum subpage-multiple size class, but small
- enough to fit in an arena-managed chunk (see the <link
+ a frontier and free list to track which regions are in use. Allocation
+ requests that are no more than half the quantum (8 or 16, depending on
+ architecture) are rounded up to the nearest power of two that is at least
+ <code language="C">sizeof(<type>double</type>)</code>. All other small
+ object size classes are multiples of the quantum, spaced such that internal
+ fragmentation is limited to approximately 25% for all but the smallest size
+ classes. Allocation requests that are larger than the maximum small size
+ class, but small enough to fit in an arena-managed chunk (see the <link
linkend="opt.lg_chunk"><mallctl>opt.lg_chunk</mallctl></link> option), are
rounded up to the nearest run size. Allocation requests that are too large
to fit in an arena-managed chunk are rounded up to the nearest multiple of
<table xml:id="size_classes" frame="all">
<title>Size classes</title>
- <tgroup cols="3" align="left" colsep="1" rowsep="1">
- <colspec colname="c1"/>
- <colspec colname="c2"/>
- <colspec colname="c3"/>
+ <tgroup cols="3" colsep="1" rowsep="1">
+ <colspec colname="c1" align="left"/>
+ <colspec colname="c2" align="right"/>
+ <colspec colname="c3" align="left"/>
<thead>
<row>
<entry>Category</entry>
- <entry>Subcategory</entry>
+ <entry>Spacing</entry>
<entry>Size</entry>
</row>
</thead>
<tbody>
<row>
- <entry morerows="3">Small</entry>
- <entry>Tiny</entry>
+ <entry morerows="6">Small</entry>
+ <entry>lg</entry>
<entry>[8]</entry>
</row>
<row>
- <entry>Quantum-spaced</entry>
+ <entry>16</entry>
<entry>[16, 32, 48, ..., 128]</entry>
</row>
<row>
- <entry>Cacheline-spaced</entry>
- <entry>[192, 256, 320, ..., 512]</entry>
+ <entry>32</entry>
+ <entry>[160, 192, 224, 256]</entry>
</row>
<row>
- <entry>Subpage-spaced</entry>
- <entry>[768, 1024, 1280, ..., 3840]</entry>
+ <entry>64</entry>
+ <entry>[320, 384, 448, 512]</entry>
</row>
<row>
- <entry namest="c1" nameend="c2">Large</entry>
+ <entry>128</entry>
+ <entry>[640, 768, 896, 1024]</entry>
+ </row>
+ <row>
+ <entry>256</entry>
+ <entry>[1280, 1536, 1792, 2048]</entry>
+ </row>
+ <row>
+ <entry>512</entry>
+ <entry>[2560, 3072, 3584]</entry>
+ </row>
+ <row>
+ <entry>Large</entry>
+ <entry>4 KiB</entry>
<entry>[4 KiB, 8 KiB, 12 KiB, ..., 4072 KiB]</entry>
</row>
<row>
- <entry namest="c1" nameend="c2">Huge</entry>
+ <entry>Huge</entry>
+ <entry>4 MiB</entry>
<entry>[4 MiB, 8 MiB, 12 MiB, ...]</entry>
</row>
</tbody>
<varlistentry>
<term>
- <mallctl>config.dynamic_page_shift</mallctl>
+ <mallctl>config.fill</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--enable-dynamic-page-shift</option> was
- specified during build configuration.</para></listitem>
+ <listitem><para><option>--enable-fill</option> was specified during
+ build configuration.</para></listitem>
</varlistentry>
<varlistentry>
<term>
- <mallctl>config.fill</mallctl>
+ <mallctl>config.lazy_lock</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--enable-fill</option> was specified during
+ <listitem><para><option>--enable-lazy-lock</option> was specified
+ during build configuration.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <mallctl>config.mremap</mallctl>
+ (<type>bool</type>)
+ <literal>r-</literal>
+ </term>
+ <listitem><para><option>--enable-mremap</option> was specified during
build configuration.</para></listitem>
</varlistentry>
<varlistentry>
<term>
- <mallctl>config.lazy_lock</mallctl>
+ <mallctl>config.munmap</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--enable-lazy-lock</option> was specified
- during build configuration.</para></listitem>
+ <listitem><para><option>--enable-munmap</option> was specified during
+ build configuration.</para></listitem>
</varlistentry>
<varlistentry>
<varlistentry>
<term>
- <mallctl>config.swap</mallctl>
+ <mallctl>config.tcache</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--enable-swap</option> was specified during
- build configuration.</para></listitem>
+ <listitem><para><option>--disable-tcache</option> was not specified
+ during build configuration.</para></listitem>
</varlistentry>
<varlistentry>
<term>
- <mallctl>config.sysv</mallctl>
+ <mallctl>config.tls</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--enable-sysv</option> was specified during
+ <listitem><para><option>--disable-tls</option> was not specified during
build configuration.</para></listitem>
</varlistentry>
<varlistentry>
<term>
- <mallctl>config.tcache</mallctl>
- (<type>bool</type>)
- <literal>r-</literal>
- </term>
- <listitem><para><option>--disable-tcache</option> was not specified
- during build configuration.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>config.tiny</mallctl>
+ <mallctl>config.utrace</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--disable-tiny</option> was not specified
- during build configuration.</para></listitem>
+ <listitem><para><option>--enable-utrace</option> was specified during
+ build configuration.</para></listitem>
</varlistentry>
<varlistentry>
<term>
- <mallctl>config.tls</mallctl>
+ <mallctl>config.valgrind</mallctl>
(<type>bool</type>)
<literal>r-</literal>
</term>
- <listitem><para><option>--disable-tls</option> was not specified during
+ <listitem><para><option>--enable-valgrind</option> was specified during
build configuration.</para></listitem>
</varlistentry>
</para></listitem>
</varlistentry>
- <varlistentry id="opt.lg_qspace_max">
- <term>
- <mallctl>opt.lg_qspace_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Size (log base 2) of the maximum size class that is a
- multiple of the quantum (8 or 16 bytes, depending on architecture).
- Above this size, cacheline spacing is used for size classes. The
- default value is 128 bytes (2^7).</para></listitem>
- </varlistentry>
-
- <varlistentry id="opt.lg_cspace_max">
- <term>
- <mallctl>opt.lg_cspace_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Size (log base 2) of the maximum size class that is a
- multiple of the cacheline size (64). Above this size, subpage spacing
- (256 bytes) is used for size classes. The default value is 512 bytes
- (2^9).</para></listitem>
- </varlistentry>
-
<varlistentry id="opt.lg_chunk">
<term>
<mallctl>opt.lg_chunk</mallctl>
configuration, in which case it is enabled by default.</para></listitem>
</varlistentry>
+ <varlistentry id="opt.quarantine">
+ <term>
+ <mallctl>opt.quarantine</mallctl>
+ (<type>size_t</type>)
+ <literal>r-</literal>
+ [<option>--enable-fill</option>]
+ </term>
+ <listitem><para>Per thread quarantine size in bytes. If non-zero, each
+ thread maintains a FIFO object quarantine that stores up to the
+ specified number of bytes of memory. The quarantined memory is not
+ freed until it is released from quarantine, though it is immediately
+ junk-filled if the <link
+ linkend="opt.junk"><mallctl>opt.junk</mallctl></link> option is
+ enabled. This feature is of particular use in combination with <ulink
+ url="http://valgrind.org/">Valgrind</ulink>, which can detect attempts
+ to access quarantined objects. This is intended for debugging and will
+ impact performance negatively. The default quarantine size is
+ 0.</para></listitem>
+ </varlistentry>
+
+ <varlistentry id="opt.redzone">
+ <term>
+ <mallctl>opt.redzone</mallctl>
+ (<type>bool</type>)
+ <literal>r-</literal>
+ [<option>--enable-fill</option>]
+ </term>
+ <listitem><para>Redzones enabled/disabled. If enabled, small
+ allocations have redzones before and after them. Furthermore, if the
+ <link linkend="opt.junk"><mallctl>opt.junk</mallctl></link> option is
+ enabled, the redzones are checked for corruption during deallocation.
+ However, the primary intended purpose of this feature is to be used in
+ combination with <ulink url="http://valgrind.org/">Valgrind</ulink>,
+ which needs redzones in order to do effective buffer overflow/underflow
+ detection. This option is intended for debugging and will impact
+ performance negatively. This option is disabled by
+ default.</para></listitem>
+ </varlistentry>
+
<varlistentry id="opt.zero">
<term>
<mallctl>opt.zero</mallctl>
</para></listitem>
</varlistentry>
- <varlistentry id="opt.sysv">
+ <varlistentry id="opt.utrace">
<term>
- <mallctl>opt.sysv</mallctl>
+ <mallctl>opt.utrace</mallctl>
(<type>bool</type>)
<literal>r-</literal>
- [<option>--enable-sysv</option>]
+ [<option>--enable-utrace</option>]
</term>
- <listitem><para>If enabled, attempting to allocate zero bytes will
- return a <constant>NULL</constant> pointer instead of a valid pointer.
- (The default behavior is to make a minimal allocation and return a
- pointer to it.) This option is provided for System V compatibility.
- This option is incompatible with the <link
- linkend="opt.xmalloc"><mallctl>opt.xmalloc</mallctl></link> option.
- This option is disabled by default.</para></listitem>
+ <listitem><para>Allocation tracing based on
+ <citerefentry><refentrytitle>utrace</refentrytitle>
+ <manvolnum>2</manvolnum></citerefentry> enabled/disabled. This option
+ is disabled by default.</para></listitem>
+ </varlistentry>
+
+ <varlistentry id="opt.valgrind">
+ <term>
+ <mallctl>opt.valgrind</mallctl>
+ (<type>bool</type>)
+ <literal>r-</literal>
+ [<option>--enable-valgrind</option>]
+ </term>
+ <listitem><para><ulink url="http://valgrind.org/">Valgrind</ulink>
+ support enabled/disabled. If enabled, several other options are
+ automatically modified during options processing to work well with
+ Valgrind: <link linkend="opt.junk"><mallctl>opt.junk</mallctl></link>
+ and <link linkend="opt.zero"><mallctl>opt.zero</mallctl></link> are set
+ to false, <link
+ linkend="opt.quarantine"><mallctl>opt.quarantine</mallctl></link> is
+ set to 16 MiB, and <link
+ linkend="opt.redzone"><mallctl>opt.redzone</mallctl></link> is set to
+ true. This option is disabled by default.</para></listitem>
</varlistentry>
<varlistentry id="opt.xmalloc">
allocations to be satisfied without performing any thread
synchronization, at the cost of increased memory use. See the
<link
- linkend="opt.lg_tcache_gc_sweep"><mallctl>opt.lg_tcache_gc_sweep</mallctl></link>
- and <link
linkend="opt.lg_tcache_max"><mallctl>opt.lg_tcache_max</mallctl></link>
- options for related tuning information. This option is enabled by
+ option for related tuning information. This option is enabled by
default.</para></listitem>
</varlistentry>
- <varlistentry id="opt.lg_tcache_gc_sweep">
- <term>
- <mallctl>opt.lg_tcache_gc_sweep</mallctl>
- (<type>ssize_t</type>)
- <literal>r-</literal>
- [<option>--enable-tcache</option>]
- </term>
- <listitem><para>Approximate interval (log base 2) between full
- thread-specific cache garbage collection sweeps, counted in terms of
- thread-specific cache allocation/deallocation events. Garbage
- collection is actually performed incrementally, one size class at a
- time, in order to avoid large collection pauses. The default sweep
- interval is 8192 (2^13); setting this option to -1 will disable garbage
- collection.</para></listitem>
- </varlistentry>
-
<varlistentry id="opt.lg_tcache_max">
<term>
<mallctl>opt.lg_tcache_max</mallctl>
[<option>--enable-prof</option>]
</term>
<listitem><para>Memory profiling enabled/disabled. If enabled, profile
- memory allocation activity, and use an
- <citerefentry><refentrytitle>atexit</refentrytitle>
- <manvolnum>3</manvolnum></citerefentry> function to dump final memory
- usage to a file named according to the pattern
- <filename><prefix>.<pid>.<seq>.f.heap</filename>,
- where <literal><prefix></literal> is controlled by the <link
- linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
- option. See the <link
- linkend="opt.lg_prof_bt_max"><mallctl>opt.lg_prof_bt_max</mallctl></link>
- option for backtrace depth control. See the <link
+ memory allocation activity. See the <link
linkend="opt.prof_active"><mallctl>opt.prof_active</mallctl></link>
option for on-the-fly activation/deactivation. See the <link
linkend="opt.lg_prof_sample"><mallctl>opt.lg_prof_sample</mallctl></link>
option for probabilistic sampling control. See the <link
linkend="opt.prof_accum"><mallctl>opt.prof_accum</mallctl></link>
option for control of cumulative sample reporting. See the <link
- linkend="opt.lg_prof_tcmax"><mallctl>opt.lg_prof_tcmax</mallctl></link>
- option for control of per thread backtrace caching. See the <link
linkend="opt.lg_prof_interval"><mallctl>opt.lg_prof_interval</mallctl></link>
- option for information on interval-triggered profile dumping, and the
- <link linkend="opt.prof_gdump"><mallctl>opt.prof_gdump</mallctl></link>
- option for information on high-water-triggered profile dumping.
- Profile output is compatible with the included <command>pprof</command>
- Perl script, which originates from the <ulink
- url="http://code.google.com/p/google-perftools/">google-perftools
+ option for information on interval-triggered profile dumping, the <link
+ linkend="opt.prof_gdump"><mallctl>opt.prof_gdump</mallctl></link>
+ option for information on high-water-triggered profile dumping, and the
+ <link linkend="opt.prof_final"><mallctl>opt.prof_final</mallctl></link>
+ option for final profile dumping. Profile output is compatible with
+ the included <command>pprof</command> Perl script, which originates
+ from the <ulink url="http://code.google.com/p/gperftools/">gperftools
package</ulink>.</para></listitem>
</varlistentry>
<filename>jeprof</filename>.</para></listitem>
</varlistentry>
- <varlistentry id="opt.lg_prof_bt_max">
- <term>
- <mallctl>opt.lg_prof_bt_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- [<option>--enable-prof</option>]
- </term>
- <listitem><para>Maximum backtrace depth (log base 2) when profiling
- memory allocation activity. The default is 128 (2^7).</para></listitem>
- </varlistentry>
-
<varlistentry id="opt.prof_active">
<term>
<mallctl>opt.prof_active</mallctl>
<listitem><para>Average interval (log base 2) between allocation
samples, as measured in bytes of allocation activity. Increasing the
sampling interval decreases profile fidelity, but also decreases the
- computational overhead. The default sample interval is 1 (2^0) (i.e.
- all allocations are sampled).</para></listitem>
+ computational overhead. The default sample interval is 512 KiB (2^19
+ B).</para></listitem>
</varlistentry>
<varlistentry id="opt.prof_accum">
dumps enabled/disabled. If this option is enabled, every unique
backtrace must be stored for the duration of execution. Depending on
the application, this can impose a large memory overhead, and the
- cumulative counts are not always of interest. See the
- <link
- linkend="opt.lg_prof_tcmax"><mallctl>opt.lg_prof_tcmax</mallctl></link>
- option for control of per thread backtrace caching, which has important
- interactions. This option is enabled by default.</para></listitem>
- </varlistentry>
-
- <varlistentry id="opt.lg_prof_tcmax">
- <term>
- <mallctl>opt.lg_prof_tcmax</mallctl>
- (<type>ssize_t</type>)
- <literal>r-</literal>
- [<option>--enable-prof</option>]
- </term>
- <listitem><para>Maximum per thread backtrace cache (log base 2) used
- for heap profiling. A backtrace can only be discarded if the
- <link linkend="opt.prof_accum"><mallctl>opt.prof_accum</mallctl></link>
- option is disabled, and no thread caches currently refer to the
- backtrace. Therefore, a backtrace cache limit should be imposed if the
- intention is to limit how much memory is used by backtraces. By
- default, no limit is imposed (encoded as -1).
- </para></listitem>
+ cumulative counts are not always of interest. This option is disabled
+ by default.</para></listitem>
</varlistentry>
<varlistentry id="opt.lg_prof_interval">
option. This option is disabled by default.</para></listitem>
</varlistentry>
+ <varlistentry id="opt.prof_final">
+ <term>
+ <mallctl>opt.prof_final</mallctl>
+ (<type>bool</type>)
+ <literal>r-</literal>
+ [<option>--enable-prof</option>]
+ </term>
+ <listitem><para>Use an
+ <citerefentry><refentrytitle>atexit</refentrytitle>
+ <manvolnum>3</manvolnum></citerefentry> function to dump final memory
+ usage to a file named according to the pattern
+ <filename><prefix>.<pid>.<seq>.f.heap</filename>,
+ where <literal><prefix></literal> is controlled by the <link
+ linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
+ option. This option is enabled by default.</para></listitem>
+ </varlistentry>
+
<varlistentry id="opt.prof_leak">
<term>
<mallctl>opt.prof_leak</mallctl>
<citerefentry><refentrytitle>atexit</refentrytitle>
<manvolnum>3</manvolnum></citerefentry> function to report memory leaks
detected by allocation sampling. See the
- <link
- linkend="opt.lg_prof_bt_max"><mallctl>opt.lg_prof_bt_max</mallctl></link>
- option for backtrace depth control. See the
<link linkend="opt.prof"><mallctl>opt.prof</mallctl></link> option for
information on analyzing heap profile output. This option is disabled
by default.</para></listitem>
</varlistentry>
- <varlistentry id="opt.overcommit">
- <term>
- <mallctl>opt.overcommit</mallctl>
- (<type>bool</type>)
- <literal>r-</literal>
- [<option>--enable-swap</option>]
- </term>
- <listitem><para>Over-commit enabled/disabled. If enabled, over-commit
- memory as a side effect of using anonymous
- <citerefentry><refentrytitle>mmap</refentrytitle>
- <manvolnum>2</manvolnum></citerefentry> or
- <citerefentry><refentrytitle>sbrk</refentrytitle>
- <manvolnum>2</manvolnum></citerefentry> for virtual memory allocation.
- In order for overcommit to be disabled, the <link
- linkend="swap.fds"><mallctl>swap.fds</mallctl></link> mallctl must have
- been successfully written to. This option is enabled by
- default.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>tcache.flush</mallctl>
- (<type>void</type>)
- <literal>--</literal>
- [<option>--enable-tcache</option>]
- </term>
- <listitem><para>Flush calling thread's tcache. This interface releases
- all cached objects and internal data structures associated with the
- calling thread's thread-specific cache. Ordinarily, this interface
- need not be called, since automatic periodic incremental garbage
- collection occurs, and the thread cache is automatically discarded when
- a thread exits. However, garbage collection is triggered by allocation
- activity, so it is possible for a thread that stops
- allocating/deallocating to retain its cache indefinitely, in which case
- the developer may find manual flushing useful.</para></listitem>
- </varlistentry>
-
<varlistentry>
<term>
<mallctl>thread.arena</mallctl>
<function>mallctl*<parameter/></function> calls.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term>
+ <mallctl>thread.tcache.enabled</mallctl>
+ (<type>bool</type>)
+ <literal>rw</literal>
+ [<option>--enable-tcache</option>]
+ </term>
+ <listitem><para>Enable/disable calling thread's tcache. The tcache is
+ implicitly flushed as a side effect of becoming
+ disabled (see <link
+ lenkend="thread.tcache.flush"><mallctl>thread.tcache.flush</mallctl></link>).
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <mallctl>thread.tcache.flush</mallctl>
+ (<type>void</type>)
+ <literal>--</literal>
+ [<option>--enable-tcache</option>]
+ </term>
+ <listitem><para>Flush calling thread's tcache. This interface releases
+ all cached objects and internal data structures associated with the
+ calling thread's thread-specific cache. Ordinarily, this interface
+ need not be called, since automatic periodic incremental garbage
+ collection occurs, and the thread cache is automatically discarded when
+ a thread exits. However, garbage collection is triggered by allocation
+ activity, so it is possible for a thread that stops
+ allocating/deallocating to retain its cache indefinitely, in which case
+ the developer may find manual flushing useful.</para></listitem>
+ </varlistentry>
+
<varlistentry id="arenas.narenas">
<term>
<mallctl>arenas.narenas</mallctl>
<varlistentry>
<term>
- <mallctl>arenas.cacheline</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Assumed cacheline size.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.subpage</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Subpage size class interval.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.pagesize</mallctl>
+ <mallctl>arenas.page</mallctl>
(<type>size_t</type>)
<literal>r-</literal>
</term>
<listitem><para>Page size.</para></listitem>
</varlistentry>
- <varlistentry>
- <term>
- <mallctl>arenas.chunksize</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Chunk size.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.tspace_min</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Minimum tiny size class. Tiny size classes are powers
- of two.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.tspace_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Maximum tiny size class. Tiny size classes are powers
- of two.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.qspace_min</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Minimum quantum-spaced size class.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.qspace_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Maximum quantum-spaced size class.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.cspace_min</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Minimum cacheline-spaced size class.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.cspace_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Maximum cacheline-spaced size class.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.sspace_min</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Minimum subpage-spaced size class.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.sspace_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Maximum subpage-spaced size class.</para></listitem>
- </varlistentry>
-
<varlistentry>
<term>
<mallctl>arenas.tcache_max</mallctl>
<listitem><para>Maximum thread-cached size class.</para></listitem>
</varlistentry>
- <varlistentry>
- <term>
- <mallctl>arenas.ntbins</mallctl>
- (<type>unsigned</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Number of tiny bin size classes.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.nqbins</mallctl>
- (<type>unsigned</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Number of quantum-spaced bin size
- classes.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.ncbins</mallctl>
- (<type>unsigned</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Number of cacheline-spaced bin size
- classes.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>arenas.nsbins</mallctl>
- (<type>unsigned</type>)
- <literal>r-</literal>
- </term>
- <listitem><para>Number of subpage-spaced bin size
- classes.</para></listitem>
- </varlistentry>
-
<varlistentry>
<term>
<mallctl>arenas.nbins</mallctl>
(<type>unsigned</type>)
<literal>r-</literal>
</term>
- <listitem><para>Total number of bin size classes.</para></listitem>
+ <listitem><para>Number of bin size classes.</para></listitem>
</varlistentry>
<varlistentry>
application. This is a multiple of the chunk size, and is at least as
large as <link
linkend="stats.active"><mallctl>stats.active</mallctl></link>. This
- does not include inactive chunks backed by swap files. his does not
- include inactive chunks embedded in the DSS.</para></listitem>
+ does not include inactive chunks.</para></listitem>
</varlistentry>
<varlistentry>
[<option>--enable-stats</option>]
</term>
<listitem><para>Total number of chunks actively mapped on behalf of the
- application. This does not include inactive chunks backed by swap
- files. This does not include inactive chunks embedded in the DSS.
+ application. This does not include inactive chunks.
</para></listitem>
</varlistentry>
to allocate changed.</para></listitem>
</varlistentry>
- <varlistentry>
- <term>
- <mallctl>stats.arenas.<i>.bins.<j>.highruns</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- [<option>--enable-stats</option>]
- </term>
- <listitem><para>Maximum number of runs at any time thus far.
- </para></listitem>
- </varlistentry>
-
<varlistentry>
<term>
<mallctl>stats.arenas.<i>.bins.<j>.curruns</mallctl>
class.</para></listitem>
</varlistentry>
- <varlistentry>
- <term>
- <mallctl>stats.arenas.<i>.lruns.<j>.highruns</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- [<option>--enable-stats</option>]
- </term>
- <listitem><para>Maximum number of runs at any time thus far for this
- size class.</para></listitem>
- </varlistentry>
-
<varlistentry>
<term>
<mallctl>stats.arenas.<i>.lruns.<j>.curruns</mallctl>
<listitem><para>Current number of runs for this size class.
</para></listitem>
</varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>swap.avail</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- [<option>--enable-stats --enable-swap</option>]
- </term>
- <listitem><para>Number of swap file bytes that are currently not
- associated with any chunk (i.e. mapped, but otherwise completely
- unmanaged).</para></listitem>
- </varlistentry>
-
- <varlistentry id="swap.prezeroed">
- <term>
- <mallctl>swap.prezeroed</mallctl>
- (<type>bool</type>)
- <literal>rw</literal>
- [<option>--enable-swap</option>]
- </term>
- <listitem><para>If true, the allocator assumes that the swap file(s)
- contain nothing but nil bytes. If this assumption is violated,
- allocator behavior is undefined. This value becomes read-only after
- <link linkend="swap.fds"><mallctl>swap.fds</mallctl></link> is
- successfully written to.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <mallctl>swap.nfds</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- [<option>--enable-swap</option>]
- </term>
- <listitem><para>Number of file descriptors in use for swap.
- </para></listitem>
- </varlistentry>
-
- <varlistentry id="swap.fds">
- <term>
- <mallctl>swap.fds</mallctl>
- (<type>int *</type>)
- <literal>rw</literal>
- [<option>--enable-swap</option>]
- </term>
- <listitem><para>When written to, the files associated with the
- specified file descriptors are contiguously mapped via
- <citerefentry><refentrytitle>mmap</refentrytitle>
- <manvolnum>2</manvolnum></citerefentry>. The resulting virtual memory
- region is preferred over anonymous
- <citerefentry><refentrytitle>mmap</refentrytitle>
- <manvolnum>2</manvolnum></citerefentry> and
- <citerefentry><refentrytitle>sbrk</refentrytitle>
- <manvolnum>2</manvolnum></citerefentry> memory. Note that if a file's
- size is not a multiple of the page size, it is automatically truncated
- to the nearest page size multiple. See the
- <link linkend="swap.prezeroed"><mallctl>swap.prezeroed</mallctl></link>
- mallctl for specifying that the files are pre-zeroed.</para></listitem>
- </varlistentry>
</variablelist>
</refsect1>
<refsect1 id="debugging_malloc_problems">
<para>This implementation does not provide much detail about the problems
it detects, because the performance impact for storing such information
- would be prohibitive. There are a number of allocator implementations
- available on the Internet which focus on detecting and pinpointing problems
- by trading performance for extra sanity checks and detailed
- diagnostics.</para>
+ would be prohibitive. However, jemalloc does integrate with the most
+ excellent <ulink url="http://valgrind.org/">Valgrind</ulink> tool if the
+ <option>--enable-valgrind</option> configuration option is enabled and the
+ <link linkend="opt.valgrind"><mallctl>opt.valgrind</mallctl></link> option
+ is enabled.</para>
</refsect1>
<refsect1 id="diagnostic_messages">
<title>DIAGNOSTIC MESSAGES</title>
</variablelist>
</para>
+ <para>The <function>aligned_alloc<parameter/></function> function returns
+ a pointer to the allocated memory if successful; otherwise a
+ <constant>NULL</constant> pointer is returned and
+ <varname>errno</varname> is set. The
+ <function>aligned_alloc<parameter/></function> function will fail if:
+ <variablelist>
+ <varlistentry>
+ <term><errorname>EINVAL</errorname></term>
+
+ <listitem><para>The <parameter>alignment</parameter> parameter is
+ not a power of 2.
+ </para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorname>ENOMEM</errorname></term>
+
+ <listitem><para>Memory allocation error.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+
<para>The <function>realloc<parameter/></function> function returns a
pointer, possibly identical to <parameter>ptr</parameter>, to the
allocated memory if successful; otherwise a <constant>NULL</constant>
<title>Experimental API</title>
<para>The <function>allocm<parameter/></function>,
<function>rallocm<parameter/></function>,
- <function>sallocm<parameter/></function>, and
- <function>dallocm<parameter/></function> functions return
+ <function>sallocm<parameter/></function>,
+ <function>dallocm<parameter/></function>, and
+ <function>nallocm<parameter/></function> functions return
<constant>ALLOCM_SUCCESS</constant> on success; otherwise they return an
- error value. The <function>allocm<parameter/></function> and
- <function>rallocm<parameter/></function> functions will fail if:
+ error value. The <function>allocm<parameter/></function>,
+ <function>rallocm<parameter/></function>, and
+ <function>nallocm<parameter/></function> functions will fail if:
<variablelist>
<varlistentry>
<term><errorname>ALLOCM_ERR_OOM</errorname></term>
<manvolnum>2</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sbrk</refentrytitle>
<manvolnum>2</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>utrace</refentrytitle>
+ <manvolnum>2</manvolnum></citerefentry>,
<citerefentry><refentrytitle>alloca</refentrytitle>
<manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>atexit</refentrytitle>
projects / redis.git / blobdiff