8d6a3e8321
Add mallctls: - arenas.lg_dirty_mult is initialized via opt.lg_dirty_mult, and can be modified to change the initial lg_dirty_mult setting for newly created arenas. - arena.<i>.lg_dirty_mult controls an individual arena's dirty page purging threshold, and synchronously triggers any purging that may be necessary to maintain the constraint. - arena.<i>.chunk.purge allows the per arena dirty page purging function to be replaced. This resolves #93.
2628 lines
114 KiB
XML
2628 lines
114 KiB
XML
<?xml version='1.0' encoding='UTF-8'?>
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<?xml-stylesheet type="text/xsl"
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href="http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl"?>
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
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"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
|
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]>
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|
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<refentry>
|
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<refentryinfo>
|
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<title>User Manual</title>
|
|
<productname>jemalloc</productname>
|
|
<releaseinfo role="version">@jemalloc_version@</releaseinfo>
|
|
<authorgroup>
|
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<author>
|
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<firstname>Jason</firstname>
|
|
<surname>Evans</surname>
|
|
<personblurb>Author</personblurb>
|
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</author>
|
|
</authorgroup>
|
|
</refentryinfo>
|
|
<refmeta>
|
|
<refentrytitle>JEMALLOC</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
<refnamediv>
|
|
<refdescriptor>jemalloc</refdescriptor>
|
|
<refname>jemalloc</refname>
|
|
<!-- Each refname causes a man page file to be created. Only if this were
|
|
the system malloc(3) implementation would these files be appropriate.
|
|
<refname>malloc</refname>
|
|
<refname>calloc</refname>
|
|
<refname>posix_memalign</refname>
|
|
<refname>aligned_alloc</refname>
|
|
<refname>realloc</refname>
|
|
<refname>free</refname>
|
|
<refname>mallocx</refname>
|
|
<refname>rallocx</refname>
|
|
<refname>xallocx</refname>
|
|
<refname>sallocx</refname>
|
|
<refname>dallocx</refname>
|
|
<refname>sdallocx</refname>
|
|
<refname>nallocx</refname>
|
|
<refname>mallctl</refname>
|
|
<refname>mallctlnametomib</refname>
|
|
<refname>mallctlbymib</refname>
|
|
<refname>malloc_stats_print</refname>
|
|
<refname>malloc_usable_size</refname>
|
|
-->
|
|
<refpurpose>general purpose memory allocation functions</refpurpose>
|
|
</refnamediv>
|
|
<refsect1 id="library">
|
|
<title>LIBRARY</title>
|
|
<para>This manual describes jemalloc @jemalloc_version@. More information
|
|
can be found at the <ulink
|
|
url="http://www.canonware.com/jemalloc/">jemalloc website</ulink>.</para>
|
|
</refsect1>
|
|
<refsynopsisdiv>
|
|
<title>SYNOPSIS</title>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <<filename class="headerfile">jemalloc/jemalloc.h</filename>></funcsynopsisinfo>
|
|
<refsect2>
|
|
<title>Standard API</title>
|
|
<funcprototype>
|
|
<funcdef>void *<function>malloc</function></funcdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void *<function>calloc</function></funcdef>
|
|
<paramdef>size_t <parameter>number</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>int <function>posix_memalign</function></funcdef>
|
|
<paramdef>void **<parameter>ptr</parameter></paramdef>
|
|
<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>size_t <parameter>size</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void <function>free</function></funcdef>
|
|
<paramdef>void *<parameter>ptr</parameter></paramdef>
|
|
</funcprototype>
|
|
</refsect2>
|
|
<refsect2>
|
|
<title>Non-standard API</title>
|
|
<funcprototype>
|
|
<funcdef>void *<function>mallocx</function></funcdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void *<function>rallocx</function></funcdef>
|
|
<paramdef>void *<parameter>ptr</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>size_t <function>xallocx</function></funcdef>
|
|
<paramdef>void *<parameter>ptr</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>size_t <parameter>extra</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>size_t <function>sallocx</function></funcdef>
|
|
<paramdef>void *<parameter>ptr</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void <function>dallocx</function></funcdef>
|
|
<paramdef>void *<parameter>ptr</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void <function>sdallocx</function></funcdef>
|
|
<paramdef>void *<parameter>ptr</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>size_t <function>nallocx</function></funcdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>int <function>mallctl</function></funcdef>
|
|
<paramdef>const char *<parameter>name</parameter></paramdef>
|
|
<paramdef>void *<parameter>oldp</parameter></paramdef>
|
|
<paramdef>size_t *<parameter>oldlenp</parameter></paramdef>
|
|
<paramdef>void *<parameter>newp</parameter></paramdef>
|
|
<paramdef>size_t <parameter>newlen</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>int <function>mallctlnametomib</function></funcdef>
|
|
<paramdef>const char *<parameter>name</parameter></paramdef>
|
|
<paramdef>size_t *<parameter>mibp</parameter></paramdef>
|
|
<paramdef>size_t *<parameter>miblenp</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>int <function>mallctlbymib</function></funcdef>
|
|
<paramdef>const size_t *<parameter>mib</parameter></paramdef>
|
|
<paramdef>size_t <parameter>miblen</parameter></paramdef>
|
|
<paramdef>void *<parameter>oldp</parameter></paramdef>
|
|
<paramdef>size_t *<parameter>oldlenp</parameter></paramdef>
|
|
<paramdef>void *<parameter>newp</parameter></paramdef>
|
|
<paramdef>size_t <parameter>newlen</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void <function>malloc_stats_print</function></funcdef>
|
|
<paramdef>void <parameter>(*write_cb)</parameter>
|
|
<funcparams>void *, const char *</funcparams>
|
|
</paramdef>
|
|
<paramdef>void *<parameter>cbopaque</parameter></paramdef>
|
|
<paramdef>const char *<parameter>opts</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>size_t <function>malloc_usable_size</function></funcdef>
|
|
<paramdef>const void *<parameter>ptr</parameter></paramdef>
|
|
</funcprototype>
|
|
<funcprototype>
|
|
<funcdef>void <function>(*malloc_message)</function></funcdef>
|
|
<paramdef>void *<parameter>cbopaque</parameter></paramdef>
|
|
<paramdef>const char *<parameter>s</parameter></paramdef>
|
|
</funcprototype>
|
|
<para><type>const char *</type><varname>malloc_conf</varname>;</para>
|
|
</refsect2>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
<refsect1 id="description">
|
|
<title>DESCRIPTION</title>
|
|
<refsect2>
|
|
<title>Standard API</title>
|
|
|
|
<para>The <function>malloc<parameter/></function> function allocates
|
|
<parameter>size</parameter> bytes of uninitialized memory. The allocated
|
|
space is suitably aligned (after possible pointer coercion) for storage
|
|
of any type of object.</para>
|
|
|
|
<para>The <function>calloc<parameter/></function> function allocates
|
|
space for <parameter>number</parameter> objects, each
|
|
<parameter>size</parameter> bytes in length. The result is identical to
|
|
calling <function>malloc<parameter/></function> with an argument of
|
|
<parameter>number</parameter> * <parameter>size</parameter>, with the
|
|
exception that the allocated memory is explicitly initialized to zero
|
|
bytes.</para>
|
|
|
|
<para>The <function>posix_memalign<parameter/></function> function
|
|
allocates <parameter>size</parameter> bytes of memory such that the
|
|
allocation's base address is a multiple of
|
|
<parameter>alignment</parameter>, and returns the allocation in the value
|
|
pointed to by <parameter>ptr</parameter>. The requested
|
|
<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 a 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
|
|
contents of the memory are unchanged up to the lesser of the new and old
|
|
sizes. If the new size is larger, the contents of the newly allocated
|
|
portion of the memory are undefined. Upon success, the memory referenced
|
|
by <parameter>ptr</parameter> is freed and a pointer to the newly
|
|
allocated memory is returned. Note that
|
|
<function>realloc<parameter/></function> may move the memory allocation,
|
|
resulting in a different return value than <parameter>ptr</parameter>.
|
|
If <parameter>ptr</parameter> is <constant>NULL</constant>, the
|
|
<function>realloc<parameter/></function> function behaves identically to
|
|
<function>malloc<parameter/></function> for the specified size.</para>
|
|
|
|
<para>The <function>free<parameter/></function> function causes the
|
|
allocated memory referenced by <parameter>ptr</parameter> to be made
|
|
available for future allocations. If <parameter>ptr</parameter> is
|
|
<constant>NULL</constant>, no action occurs.</para>
|
|
</refsect2>
|
|
<refsect2>
|
|
<title>Non-standard API</title>
|
|
<para>The <function>mallocx<parameter/></function>,
|
|
<function>rallocx<parameter/></function>,
|
|
<function>xallocx<parameter/></function>,
|
|
<function>sallocx<parameter/></function>,
|
|
<function>dallocx<parameter/></function>,
|
|
<function>sdallocx<parameter/></function>, and
|
|
<function>nallocx<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
|
|
specify one or more of the following:
|
|
<variablelist>
|
|
<varlistentry id="MALLOCX_LG_ALIGN">
|
|
<term><constant>MALLOCX_LG_ALIGN(<parameter>la</parameter>)
|
|
</constant></term>
|
|
|
|
<listitem><para>Align the memory allocation to start at an address
|
|
that is a multiple of <code language="C">(1 <<
|
|
<parameter>la</parameter>)</code>. This macro does not validate
|
|
that <parameter>la</parameter> is within the valid
|
|
range.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry id="MALLOCX_ALIGN">
|
|
<term><constant>MALLOCX_ALIGN(<parameter>a</parameter>)
|
|
</constant></term>
|
|
|
|
<listitem><para>Align the memory allocation to start at an address
|
|
that is a multiple of <parameter>a</parameter>, where
|
|
<parameter>a</parameter> is a power of two. This macro does not
|
|
validate that <parameter>a</parameter> is a power of 2.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry id="MALLOCX_ZERO">
|
|
<term><constant>MALLOCX_ZERO</constant></term>
|
|
|
|
<listitem><para>Initialize newly allocated memory to contain zero
|
|
bytes. In the growing reallocation case, the real size prior to
|
|
reallocation defines the boundary between untouched bytes and those
|
|
that are initialized to contain zero bytes. If this macro is
|
|
absent, newly allocated memory is uninitialized.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry id="MALLOCX_TCACHE">
|
|
<term><constant>MALLOCX_TCACHE(<parameter>tc</parameter>)
|
|
</constant></term>
|
|
|
|
<listitem><para>Use the thread-specific cache (tcache) specified by
|
|
the identifier <parameter>tc</parameter>, which must have been
|
|
acquired via the <link
|
|
linkend="tcache.create"><mallctl>tcache.create</mallctl></link>
|
|
mallctl. This macro does not validate that
|
|
<parameter>tc</parameter> specifies a valid
|
|
identifier.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry id="MALLOC_TCACHE_NONE">
|
|
<term><constant>MALLOCX_TCACHE_NONE</constant></term>
|
|
|
|
<listitem><para>Do not use a thread-specific cache (tcache). Unless
|
|
<constant>MALLOCX_TCACHE(<parameter>tc</parameter>)</constant> or
|
|
<constant>MALLOCX_TCACHE_NONE</constant> is specified, an
|
|
automatically managed tcache will be used under many circumstances.
|
|
This macro cannot be used in the same <parameter>flags</parameter>
|
|
argument as
|
|
<constant>MALLOCX_TCACHE(<parameter>tc</parameter>)</constant>.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry id="MALLOCX_ARENA">
|
|
<term><constant>MALLOCX_ARENA(<parameter>a</parameter>)
|
|
</constant></term>
|
|
|
|
<listitem><para>Use the arena specified by the index
|
|
<parameter>a</parameter>. This macro has no effect for regions that
|
|
were allocated via an arena other than the one specified. This
|
|
macro does not validate that <parameter>a</parameter> specifies an
|
|
arena index in the valid range.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</para>
|
|
|
|
<para>The <function>mallocx<parameter/></function> function allocates at
|
|
least <parameter>size</parameter> bytes of memory, and returns a pointer
|
|
to the base address of the allocation. Behavior is undefined if
|
|
<parameter>size</parameter> is <constant>0</constant>, or if request size
|
|
overflows due to size class and/or alignment constraints.</para>
|
|
|
|
<para>The <function>rallocx<parameter/></function> function resizes the
|
|
allocation at <parameter>ptr</parameter> to be at least
|
|
<parameter>size</parameter> bytes, and returns a pointer to the base
|
|
address of the resulting allocation, which may or may not have moved from
|
|
its original location. Behavior is undefined if
|
|
<parameter>size</parameter> is <constant>0</constant>, or if request size
|
|
overflows due to size class and/or alignment constraints.</para>
|
|
|
|
<para>The <function>xallocx<parameter/></function> function resizes the
|
|
allocation at <parameter>ptr</parameter> in place to be at least
|
|
<parameter>size</parameter> bytes, and returns the real size of the
|
|
allocation. If <parameter>extra</parameter> is non-zero, an attempt is
|
|
made to resize the allocation to be at least <code
|
|
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 to resize.
|
|
Behavior is 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>sallocx<parameter/></function> function returns the
|
|
real size of the allocation at <parameter>ptr</parameter>.</para>
|
|
|
|
<para>The <function>dallocx<parameter/></function> function causes the
|
|
memory referenced by <parameter>ptr</parameter> to be made available for
|
|
future allocations.</para>
|
|
|
|
<para>The <function>sdallocx<parameter/></function> function is an
|
|
extension of <function>dallocx<parameter/></function> with a
|
|
<parameter>size</parameter> parameter to allow the caller to pass in the
|
|
allocation size as an optimization. The minimum valid input size is the
|
|
original requested size of the allocation, and the maximum valid input
|
|
size is the corresponding value returned by
|
|
<function>nallocx<parameter/></function> or
|
|
<function>sallocx<parameter/></function>.</para>
|
|
|
|
<para>The <function>nallocx<parameter/></function> function allocates no
|
|
memory, but it performs the same size computation as the
|
|
<function>mallocx<parameter/></function> function, and returns the real
|
|
size of the allocation that would result from the equivalent
|
|
<function>mallocx<parameter/></function> function call. Behavior is
|
|
undefined if <parameter>size</parameter> is <constant>0</constant>, or if
|
|
request size overflows due to size class and/or alignment
|
|
constraints.</para>
|
|
|
|
<para>The <function>mallctl<parameter/></function> function provides a
|
|
general interface for introspecting the memory allocator, as well as
|
|
setting modifiable parameters and triggering actions. The
|
|
period-separated <parameter>name</parameter> argument specifies a
|
|
location in a tree-structured namespace; see the <xref
|
|
linkend="mallctl_namespace" xrefstyle="template:%t"/> section for
|
|
documentation on the tree contents. To read a value, pass a pointer via
|
|
<parameter>oldp</parameter> to adequate space to contain the value, and a
|
|
pointer to its length via <parameter>oldlenp</parameter>; otherwise pass
|
|
<constant>NULL</constant> and <constant>NULL</constant>. Similarly, to
|
|
write a value, pass a pointer to the value via
|
|
<parameter>newp</parameter>, and its length via
|
|
<parameter>newlen</parameter>; otherwise pass <constant>NULL</constant>
|
|
and <constant>0</constant>.</para>
|
|
|
|
<para>The <function>mallctlnametomib<parameter/></function> function
|
|
provides a way to avoid repeated name lookups for applications that
|
|
repeatedly query the same portion of the namespace, by translating a name
|
|
to a “Management Information Base” (MIB) that can be passed
|
|
repeatedly to <function>mallctlbymib<parameter/></function>. Upon
|
|
successful return from <function>mallctlnametomib<parameter/></function>,
|
|
<parameter>mibp</parameter> contains an array of
|
|
<parameter>*miblenp</parameter> integers, where
|
|
<parameter>*miblenp</parameter> is the lesser of the number of components
|
|
in <parameter>name</parameter> and the input value of
|
|
<parameter>*miblenp</parameter>. Thus it is possible to pass a
|
|
<parameter>*miblenp</parameter> that is smaller than the number of
|
|
period-separated name components, which results in a partial MIB that can
|
|
be used as the basis for constructing a complete MIB. For name
|
|
components that are integers (e.g. the 2 in
|
|
<link
|
|
linkend="arenas.bin.i.size"><mallctl>arenas.bin.2.size</mallctl></link>),
|
|
the corresponding MIB component will always be that integer. Therefore,
|
|
it is legitimate to construct code like the following: <programlisting
|
|
language="C"><![CDATA[
|
|
unsigned nbins, i;
|
|
size_t mib[4];
|
|
size_t len, miblen;
|
|
|
|
len = sizeof(nbins);
|
|
mallctl("arenas.nbins", &nbins, &len, NULL, 0);
|
|
|
|
miblen = 4;
|
|
mallctlnametomib("arenas.bin.0.size", mib, &miblen);
|
|
for (i = 0; i < nbins; i++) {
|
|
size_t bin_size;
|
|
|
|
mib[2] = i;
|
|
len = sizeof(bin_size);
|
|
mallctlbymib(mib, miblen, &bin_size, &len, NULL, 0);
|
|
/* Do something with bin_size... */
|
|
}]]></programlisting></para>
|
|
|
|
<para>The <function>malloc_stats_print<parameter/></function> function
|
|
writes human-readable summary statistics via the
|
|
<parameter>write_cb</parameter> callback function pointer and
|
|
<parameter>cbopaque</parameter> data passed to
|
|
<parameter>write_cb</parameter>, or
|
|
<function>malloc_message<parameter/></function> if
|
|
<parameter>write_cb</parameter> is <constant>NULL</constant>. This
|
|
function can be called repeatedly. General information that never
|
|
changes during execution can be omitted by specifying "g" as a character
|
|
within the <parameter>opts</parameter> string. Note that
|
|
<function>malloc_message<parameter/></function> uses the
|
|
<function>mallctl*<parameter/></function> functions internally, so
|
|
inconsistent statistics can be reported if multiple threads use these
|
|
functions simultaneously. If <option>--enable-stats</option> is
|
|
specified during configuration, “m” and “a” can
|
|
be specified to omit merged arena and per arena statistics, respectively;
|
|
“b”, “l”, and “h” can be specified to
|
|
omit per size class statistics for bins, large objects, and huge objects,
|
|
respectively. Unrecognized characters are silently ignored. Note that
|
|
thread caching may prevent some statistics from being completely up to
|
|
date, since extra locking would be required to merge counters that track
|
|
thread cache operations.
|
|
</para>
|
|
|
|
<para>The <function>malloc_usable_size<parameter/></function> function
|
|
returns the usable size of the allocation pointed to by
|
|
<parameter>ptr</parameter>. The return value may be larger than the size
|
|
that was requested during allocation. The
|
|
<function>malloc_usable_size<parameter/></function> function is not a
|
|
mechanism for in-place <function>realloc<parameter/></function>; rather
|
|
it is provided solely as a tool for introspection purposes. Any
|
|
discrepancy between the requested allocation size and the size reported
|
|
by <function>malloc_usable_size<parameter/></function> should not be
|
|
depended on, since such behavior is entirely implementation-dependent.
|
|
</para>
|
|
</refsect2>
|
|
</refsect1>
|
|
<refsect1 id="tuning">
|
|
<title>TUNING</title>
|
|
<para>Once, when the first call is made to one of the memory allocation
|
|
routines, the allocator initializes its internals based in part on various
|
|
options that can be specified at compile- or run-time.</para>
|
|
|
|
<para>The string pointed to by the global variable
|
|
<varname>malloc_conf</varname>, the “name” of the file
|
|
referenced by the symbolic link named <filename
|
|
class="symlink">/etc/malloc.conf</filename>, and the value of the
|
|
environment variable <envar>MALLOC_CONF</envar>, will be interpreted, in
|
|
that order, from left to right as options. Note that
|
|
<varname>malloc_conf</varname> may be read before
|
|
<function>main<parameter/></function> is entered, so the declaration of
|
|
<varname>malloc_conf</varname> should specify an initializer that contains
|
|
the final value to be read by jemalloc. <varname>malloc_conf</varname> is
|
|
a compile-time setting, whereas <filename
|
|
class="symlink">/etc/malloc.conf</filename> and <envar>MALLOC_CONF</envar>
|
|
can be safely set any time prior to program invocation.</para>
|
|
|
|
<para>An options string is a comma-separated list of option:value pairs.
|
|
There is one key corresponding to each <link
|
|
linkend="opt.abort"><mallctl>opt.*</mallctl></link> mallctl (see the <xref
|
|
linkend="mallctl_namespace" xrefstyle="template:%t"/> section for options
|
|
documentation). For example, <literal>abort:true,narenas:1</literal> sets
|
|
the <link linkend="opt.abort"><mallctl>opt.abort</mallctl></link> and <link
|
|
linkend="opt.narenas"><mallctl>opt.narenas</mallctl></link> options. Some
|
|
options have boolean values (true/false), others have integer values (base
|
|
8, 10, or 16, depending on prefix), and yet others have raw string
|
|
values.</para>
|
|
</refsect1>
|
|
<refsect1 id="implementation_notes">
|
|
<title>IMPLEMENTATION NOTES</title>
|
|
<para>Traditionally, allocators have used
|
|
<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> to obtain memory, which is
|
|
suboptimal for several reasons, including race conditions, increased
|
|
fragmentation, and artificial limitations on maximum usable memory. If
|
|
<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> is supported by the operating
|
|
system, this allocator uses both
|
|
<citerefentry><refentrytitle>mmap</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> and
|
|
<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>
|
|
|
|
<para>This allocator uses multiple arenas in order to reduce lock
|
|
contention for threaded programs on multi-processor systems. This works
|
|
well with regard to threading scalability, but incurs some costs. There is
|
|
a small fixed per-arena overhead, and additionally, arenas manage memory
|
|
completely independently of each other, which means a small fixed increase
|
|
in overall memory fragmentation. These overheads are not generally an
|
|
issue, given the number of arenas normally used. Note that using
|
|
substantially more arenas than the default is not likely to improve
|
|
performance, mainly due to reduced cache performance. However, it may make
|
|
sense to reduce the number of arenas if an application does not make much
|
|
use of the allocation functions.</para>
|
|
|
|
<para>In addition to multiple arenas, unless
|
|
<option>--disable-tcache</option> is specified during configuration, this
|
|
allocator supports thread-specific caching for small and large objects, in
|
|
order to make it possible to completely avoid synchronization for most
|
|
allocation requests. Such caching allows very fast allocation in the
|
|
common case, but it increases memory usage and fragmentation, since a
|
|
bounded number of objects can remain allocated in each thread cache.</para>
|
|
|
|
<para>Memory is conceptually broken into equal-sized chunks, where the
|
|
chunk size is a power of two that is greater than the page size. Chunks
|
|
are always aligned to multiples of the chunk size. This alignment makes it
|
|
possible to find metadata for user objects very quickly.</para>
|
|
|
|
<para>User objects are broken into three categories according to size:
|
|
small, large, and huge. Small and large objects are managed entirely by
|
|
arenas; huge objects are additionally aggregated in a single data structure
|
|
that is shared by all threads. Huge objects are typically used by
|
|
applications infrequently enough that this single data structure is not a
|
|
scalability issue.</para>
|
|
|
|
<para>Each chunk that is managed by an arena tracks its contents as runs of
|
|
contiguous pages (unused, backing a set of small objects, or backing one
|
|
large object). The combination of chunk alignment and chunk page maps
|
|
makes it possible to determine all metadata regarding small and large
|
|
allocations in constant time.</para>
|
|
|
|
<para>Small objects are managed in groups by page runs. Each run maintains
|
|
a bitmap 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 object size
|
|
classes are multiples of the quantum, spaced such that there are four size
|
|
classes for each doubling in size, which limits internal fragmentation to
|
|
approximately 20% for all but the smallest size classes. Small size classes
|
|
are smaller than four times the page size, large size classes are smaller
|
|
than the chunk size (see the <link
|
|
linkend="opt.lg_chunk"><mallctl>opt.lg_chunk</mallctl></link> option), and
|
|
huge size classes extend from the chunk size up to one size class less than
|
|
the full address space size.</para>
|
|
|
|
<para>Allocations are packed tightly together, which can be an issue for
|
|
multi-threaded applications. If you need to assure that allocations do not
|
|
suffer from cacheline sharing, round your allocation requests up to the
|
|
nearest multiple of the cacheline size, or specify cacheline alignment when
|
|
allocating.</para>
|
|
|
|
<para>The <function>realloc<parameter/></function>,
|
|
<function>rallocx<parameter/></function>, and
|
|
<function>xallocx<parameter/></function> functions may resize allocations
|
|
without moving them under limited circumstances. Unlike the
|
|
<function>*allocx<parameter/></function> API, the standard API does not
|
|
officially round up the usable size of an allocation to the nearest size
|
|
class, so technically it is necessary to call
|
|
<function>realloc<parameter/></function> to grow e.g. a 9-byte allocation to
|
|
16 bytes, or shrink a 16-byte allocation to 9 bytes. Growth and shrinkage
|
|
trivially succeeds in place as long as the pre-size and post-size both round
|
|
up to the same size class. No other API guarantees are made regarding
|
|
in-place resizing, but the current implementation also tries to resize large
|
|
and huge allocations in place, as long as the pre-size and post-size are
|
|
both large or both huge. In such cases shrinkage always succeeds, but
|
|
growth only succeeds if the trailing memory is currently available.</para>
|
|
|
|
<para>Assuming 256 KiB chunks, 4 KiB pages, and a 16-byte quantum on a
|
|
64-bit system, the size classes in each category are as shown in <xref
|
|
linkend="size_classes" xrefstyle="template:Table %n"/>.</para>
|
|
|
|
<table xml:id="size_classes" frame="all">
|
|
<title>Size classes</title>
|
|
<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>Spacing</entry>
|
|
<entry>Size</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry morerows="8">Small</entry>
|
|
<entry>lg</entry>
|
|
<entry>[8]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>16</entry>
|
|
<entry>[16, 32, 48, 64, 80, 96, 112, 128]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>32</entry>
|
|
<entry>[160, 192, 224, 256]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>64</entry>
|
|
<entry>[320, 384, 448, 512]</entry>
|
|
</row>
|
|
<row>
|
|
<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, 4096]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>1 KiB</entry>
|
|
<entry>[5 KiB, 6 KiB, 7 KiB, 8 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>2 KiB</entry>
|
|
<entry>[10 KiB, 12 KiB, 14 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry morerows="4">Large</entry>
|
|
<entry>2 KiB</entry>
|
|
<entry>[16 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>4 KiB</entry>
|
|
<entry>[20 KiB, 24 KiB, 28 KiB, 32 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>8 KiB</entry>
|
|
<entry>[40 KiB, 48 KiB, 54 KiB, 64 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>16 KiB</entry>
|
|
<entry>[80 KiB, 96 KiB, 112 KiB, 128 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>32 KiB</entry>
|
|
<entry>[160 KiB, 192 KiB, 224 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry morerows="9">Huge</entry>
|
|
<entry>32 KiB</entry>
|
|
<entry>[256 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>64 KiB</entry>
|
|
<entry>[320 KiB, 384 KiB, 448 KiB, 512 KiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>128 KiB</entry>
|
|
<entry>[640 KiB, 768 KiB, 896 KiB, 1 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>256 KiB</entry>
|
|
<entry>[1280 KiB, 1536 KiB, 1792 KiB, 2 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>512 KiB</entry>
|
|
<entry>[2560 KiB, 3 MiB, 3584 KiB, 4 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>1 MiB</entry>
|
|
<entry>[5 MiB, 6 MiB, 7 MiB, 8 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>2 MiB</entry>
|
|
<entry>[10 MiB, 12 MiB, 14 MiB, 16 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>4 MiB</entry>
|
|
<entry>[20 MiB, 24 MiB, 28 MiB, 32 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>8 MiB</entry>
|
|
<entry>[40 MiB, 48 MiB, 56 MiB, 64 MiB]</entry>
|
|
</row>
|
|
<row>
|
|
<entry>...</entry>
|
|
<entry>...</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</refsect1>
|
|
<refsect1 id="mallctl_namespace">
|
|
<title>MALLCTL NAMESPACE</title>
|
|
<para>The following names are defined in the namespace accessible via the
|
|
<function>mallctl*<parameter/></function> functions. Value types are
|
|
specified in parentheses, their readable/writable statuses are encoded as
|
|
<literal>rw</literal>, <literal>r-</literal>, <literal>-w</literal>, or
|
|
<literal>--</literal>, and required build configuration flags follow, if
|
|
any. A name element encoded as <literal><i></literal> or
|
|
<literal><j></literal> indicates an integer component, where the
|
|
integer varies from 0 to some upper value that must be determined via
|
|
introspection. In the case of <mallctl>stats.arenas.<i>.*</mallctl>,
|
|
<literal><i></literal> equal to <link
|
|
linkend="arenas.narenas"><mallctl>arenas.narenas</mallctl></link> can be
|
|
used to access the summation of statistics from all arenas. Take special
|
|
note of the <link linkend="epoch"><mallctl>epoch</mallctl></link> mallctl,
|
|
which controls refreshing of cached dynamic statistics.</para>
|
|
|
|
<variablelist>
|
|
<varlistentry id="version">
|
|
<term>
|
|
<mallctl>version</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Return the jemalloc version string.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="epoch">
|
|
<term>
|
|
<mallctl>epoch</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>If a value is passed in, refresh the data from which
|
|
the <function>mallctl*<parameter/></function> functions report values,
|
|
and increment the epoch. Return the current epoch. This is useful for
|
|
detecting whether another thread caused a refresh.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.debug">
|
|
<term>
|
|
<mallctl>config.debug</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-debug</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.fill">
|
|
<term>
|
|
<mallctl>config.fill</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-fill</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.lazy_lock">
|
|
<term>
|
|
<mallctl>config.lazy_lock</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-lazy-lock</option> was specified
|
|
during build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.munmap">
|
|
<term>
|
|
<mallctl>config.munmap</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-munmap</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.prof">
|
|
<term>
|
|
<mallctl>config.prof</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-prof</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.prof_libgcc">
|
|
<term>
|
|
<mallctl>config.prof_libgcc</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--disable-prof-libgcc</option> was not
|
|
specified during build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.prof_libunwind">
|
|
<term>
|
|
<mallctl>config.prof_libunwind</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-prof-libunwind</option> was specified
|
|
during build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.stats">
|
|
<term>
|
|
<mallctl>config.stats</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-stats</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.tcache">
|
|
<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 id="config.tls">
|
|
<term>
|
|
<mallctl>config.tls</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--disable-tls</option> was not specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.utrace">
|
|
<term>
|
|
<mallctl>config.utrace</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-utrace</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.valgrind">
|
|
<term>
|
|
<mallctl>config.valgrind</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-valgrind</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="config.xmalloc">
|
|
<term>
|
|
<mallctl>config.xmalloc</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para><option>--enable-xmalloc</option> was specified during
|
|
build configuration.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.abort">
|
|
<term>
|
|
<mallctl>opt.abort</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Abort-on-warning enabled/disabled. If true, most
|
|
warnings are fatal. The process will call
|
|
<citerefentry><refentrytitle>abort</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry> in these cases. This option is
|
|
disabled by default unless <option>--enable-debug</option> is
|
|
specified during configuration, in which case it is enabled by default.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.dss">
|
|
<term>
|
|
<mallctl>opt.dss</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>dss (<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry>) allocation precedence as
|
|
related to <citerefentry><refentrytitle>mmap</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> allocation. The following
|
|
settings are supported if
|
|
<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> is supported by the operating
|
|
system: “disabled”, “primary”, and
|
|
“secondary”; otherwise only “disabled” is
|
|
supported. The default is “secondary” if
|
|
<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> is supported by the operating
|
|
system; “disabled” otherwise.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.lg_chunk">
|
|
<term>
|
|
<mallctl>opt.lg_chunk</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Virtual memory chunk size (log base 2). If a chunk
|
|
size outside the supported size range is specified, the size is
|
|
silently clipped to the minimum/maximum supported size. The default
|
|
chunk size is 256 KiB (2^18).
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.narenas">
|
|
<term>
|
|
<mallctl>opt.narenas</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Maximum number of arenas to use for automatic
|
|
multiplexing of threads and arenas. The default is four times the
|
|
number of CPUs, or one if there is a single CPU.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.lg_dirty_mult">
|
|
<term>
|
|
<mallctl>opt.lg_dirty_mult</mallctl>
|
|
(<type>ssize_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Per-arena minimum ratio (log base 2) of active to dirty
|
|
pages. Some dirty unused pages may be allowed to accumulate, within
|
|
the limit set by the ratio (or one chunk worth of dirty pages,
|
|
whichever is greater), before informing the kernel about some of those
|
|
pages via <citerefentry><refentrytitle>madvise</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> or a similar system call. This
|
|
provides the kernel with sufficient information to recycle dirty pages
|
|
if physical memory becomes scarce and the pages remain unused. The
|
|
default minimum ratio is 8:1 (2^3:1); an option value of -1 will
|
|
disable dirty page purging. See <link
|
|
linkend="arenas.lg_dirty_mult"><mallctl>arenas.lg_dirty_mult</mallctl></link>
|
|
and <link
|
|
linkend="arena.i.lg_dirty_mult"><mallctl>arena.<i>.lg_dirty_mult</mallctl></link>
|
|
for related dynamic control options.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.stats_print">
|
|
<term>
|
|
<mallctl>opt.stats_print</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Enable/disable statistics printing at exit. If
|
|
enabled, the <function>malloc_stats_print<parameter/></function>
|
|
function is called at program exit via an
|
|
<citerefentry><refentrytitle>atexit</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry> function. If
|
|
<option>--enable-stats</option> is specified during configuration, this
|
|
has the potential to cause deadlock for a multi-threaded process that
|
|
exits while one or more threads are executing in the memory allocation
|
|
functions. Furthermore, <function>atexit<parameter/></function> may
|
|
allocate memory during application initialization and then deadlock
|
|
internally when jemalloc in turn calls
|
|
<function>atexit<parameter/></function>, so this option is not
|
|
univerally usable (though the application can register its own
|
|
<function>atexit<parameter/></function> function with equivalent
|
|
functionality). Therefore, this option should only be used with care;
|
|
it is primarily intended as a performance tuning aid during application
|
|
development. This option is disabled by default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.junk">
|
|
<term>
|
|
<mallctl>opt.junk</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-fill</option>]
|
|
</term>
|
|
<listitem><para>Junk filling. If set to "alloc", each byte of
|
|
uninitialized allocated memory will be initialized to
|
|
<literal>0xa5</literal>. If set to "free", all deallocated memory will
|
|
be initialized to <literal>0x5a</literal>. If set to "true", both
|
|
allocated and deallocated memory will be initialized, and if set to
|
|
"false", junk filling be disabled entirely. This is intended for
|
|
debugging and will impact performance negatively. This option is
|
|
"false" by default unless <option>--enable-debug</option> is specified
|
|
during configuration, in which case it is "true" by default unless
|
|
running inside <ulink
|
|
url="http://valgrind.org/">Valgrind</ulink>.</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 unless
|
|
running inside Valgrind, in which case the default is 16
|
|
MiB.</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 unless running inside Valgrind.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.zero">
|
|
<term>
|
|
<mallctl>opt.zero</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-fill</option>]
|
|
</term>
|
|
<listitem><para>Zero filling enabled/disabled. If enabled, each byte
|
|
of uninitialized allocated memory will be initialized to 0. Note that
|
|
this initialization only happens once for each byte, so
|
|
<function>realloc<parameter/></function> and
|
|
<function>rallocx<parameter/></function> calls do not zero memory that
|
|
was previously allocated. This is intended for debugging and will
|
|
impact performance negatively. This option is disabled by default.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.utrace">
|
|
<term>
|
|
<mallctl>opt.utrace</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-utrace</option>]
|
|
</term>
|
|
<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.xmalloc">
|
|
<term>
|
|
<mallctl>opt.xmalloc</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-xmalloc</option>]
|
|
</term>
|
|
<listitem><para>Abort-on-out-of-memory enabled/disabled. If enabled,
|
|
rather than returning failure for any allocation function, display a
|
|
diagnostic message on <constant>STDERR_FILENO</constant> and cause the
|
|
program to drop core (using
|
|
<citerefentry><refentrytitle>abort</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry>). If an application is
|
|
designed to depend on this behavior, set the option at compile time by
|
|
including the following in the source code:
|
|
<programlisting language="C"><![CDATA[
|
|
malloc_conf = "xmalloc:true";]]></programlisting>
|
|
This option is disabled by default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.tcache">
|
|
<term>
|
|
<mallctl>opt.tcache</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Thread-specific caching (tcache) enabled/disabled. When
|
|
there are multiple threads, each thread uses a tcache for objects up to
|
|
a certain size. Thread-specific caching allows many allocations to be
|
|
satisfied without performing any thread synchronization, at the cost of
|
|
increased memory use. See the <link
|
|
linkend="opt.lg_tcache_max"><mallctl>opt.lg_tcache_max</mallctl></link>
|
|
option for related tuning information. This option is enabled by
|
|
default unless running inside <ulink
|
|
url="http://valgrind.org/">Valgrind</ulink>, in which case it is
|
|
forcefully disabled.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.lg_tcache_max">
|
|
<term>
|
|
<mallctl>opt.lg_tcache_max</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Maximum size class (log base 2) to cache in the
|
|
thread-specific cache (tcache). At a minimum, all small size classes
|
|
are cached, and at a maximum all large size classes are cached. The
|
|
default maximum is 32 KiB (2^15).</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.prof">
|
|
<term>
|
|
<mallctl>opt.prof</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Memory profiling enabled/disabled. If enabled, profile
|
|
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_interval"><mallctl>opt.lg_prof_interval</mallctl></link>
|
|
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>
|
|
|
|
<varlistentry id="opt.prof_prefix">
|
|
<term>
|
|
<mallctl>opt.prof_prefix</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Filename prefix for profile dumps. If the prefix is
|
|
set to the empty string, no automatic dumps will occur; this is
|
|
primarily useful for disabling the automatic final heap dump (which
|
|
also disables leak reporting, if enabled). The default prefix is
|
|
<filename>jeprof</filename>.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.prof_active">
|
|
<term>
|
|
<mallctl>opt.prof_active</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Profiling activated/deactivated. This is a secondary
|
|
control mechanism that makes it possible to start the application with
|
|
profiling enabled (see the <link
|
|
linkend="opt.prof"><mallctl>opt.prof</mallctl></link> option) but
|
|
inactive, then toggle profiling at any time during program execution
|
|
with the <link
|
|
linkend="prof.active"><mallctl>prof.active</mallctl></link> mallctl.
|
|
This option is enabled by default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.prof_thread_active_init">
|
|
<term>
|
|
<mallctl>opt.prof_thread_active_init</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Initial setting for <link
|
|
linkend="thread.prof.active"><mallctl>thread.prof.active</mallctl></link>
|
|
in newly created threads. The initial setting for newly created threads
|
|
can also be changed during execution via the <link
|
|
linkend="prof.thread_active_init"><mallctl>prof.thread_active_init</mallctl></link>
|
|
mallctl. This option is enabled by default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.lg_prof_sample">
|
|
<term>
|
|
<mallctl>opt.lg_prof_sample</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<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 512 KiB (2^19
|
|
B).</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.prof_accum">
|
|
<term>
|
|
<mallctl>opt.prof_accum</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Reporting of cumulative object/byte counts in profile
|
|
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. This option is disabled
|
|
by default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.lg_prof_interval">
|
|
<term>
|
|
<mallctl>opt.lg_prof_interval</mallctl>
|
|
(<type>ssize_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Average interval (log base 2) between memory profile
|
|
dumps, as measured in bytes of allocation activity. The actual
|
|
interval between dumps may be sporadic because decentralized allocation
|
|
counters are used to avoid synchronization bottlenecks. Profiles are
|
|
dumped to files named according to the pattern
|
|
<filename><prefix>.<pid>.<seq>.i<iseq>.heap</filename>,
|
|
where <literal><prefix></literal> is controlled by the
|
|
<link
|
|
linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
|
|
option. By default, interval-triggered profile dumping is disabled
|
|
(encoded as -1).
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.prof_gdump">
|
|
<term>
|
|
<mallctl>opt.prof_gdump</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Set the initial state of <link
|
|
linkend="prof.gdump"><mallctl>prof.gdump</mallctl></link>, which when
|
|
enabled triggers a memory profile dump every time the total virtual
|
|
memory exceeds the previous maximum. 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. Note that <function>atexit<parameter/></function> may allocate
|
|
memory during application initialization and then deadlock internally
|
|
when jemalloc in turn calls <function>atexit<parameter/></function>, so
|
|
this option is not univerally usable (though the application can
|
|
register its own <function>atexit<parameter/></function> function with
|
|
equivalent functionality). This option is disabled by
|
|
default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="opt.prof_leak">
|
|
<term>
|
|
<mallctl>opt.prof_leak</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Leak reporting enabled/disabled. If enabled, use an
|
|
<citerefentry><refentrytitle>atexit</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry> function to report memory leaks
|
|
detected by allocation sampling. 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="thread.arena">
|
|
<term>
|
|
<mallctl>thread.arena</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Get or set the arena associated with the calling
|
|
thread. If the specified arena was not initialized beforehand (see the
|
|
<link
|
|
linkend="arenas.initialized"><mallctl>arenas.initialized</mallctl></link>
|
|
mallctl), it will be automatically initialized as a side effect of
|
|
calling this interface.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.allocated">
|
|
<term>
|
|
<mallctl>thread.allocated</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Get the total number of bytes ever allocated by the
|
|
calling thread. This counter has the potential to wrap around; it is
|
|
up to the application to appropriately interpret the counter in such
|
|
cases.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.allocatedp">
|
|
<term>
|
|
<mallctl>thread.allocatedp</mallctl>
|
|
(<type>uint64_t *</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Get a pointer to the the value that is returned by the
|
|
<link
|
|
linkend="thread.allocated"><mallctl>thread.allocated</mallctl></link>
|
|
mallctl. This is useful for avoiding the overhead of repeated
|
|
<function>mallctl*<parameter/></function> calls.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.deallocated">
|
|
<term>
|
|
<mallctl>thread.deallocated</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Get the total number of bytes ever deallocated by the
|
|
calling thread. This counter has the potential to wrap around; it is
|
|
up to the application to appropriately interpret the counter in such
|
|
cases.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.deallocatedp">
|
|
<term>
|
|
<mallctl>thread.deallocatedp</mallctl>
|
|
(<type>uint64_t *</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Get a pointer to the the value that is returned by the
|
|
<link
|
|
linkend="thread.deallocated"><mallctl>thread.deallocated</mallctl></link>
|
|
mallctl. This is useful for avoiding the overhead of repeated
|
|
<function>mallctl*<parameter/></function> calls.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.tcache.enabled">
|
|
<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
|
|
linkend="thread.tcache.flush"><mallctl>thread.tcache.flush</mallctl></link>).
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.tcache.flush">
|
|
<term>
|
|
<mallctl>thread.tcache.flush</mallctl>
|
|
(<type>void</type>)
|
|
<literal>--</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Flush calling thread's thread-specific cache (tcache).
|
|
This interface releases all cached objects and internal data structures
|
|
associated with the calling thread's tcache. 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="thread.prof.name">
|
|
<term>
|
|
<mallctl>thread.prof.name</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>r-</literal> or
|
|
<literal>-w</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Get/set the descriptive name associated with the calling
|
|
thread in memory profile dumps. An internal copy of the name string is
|
|
created, so the input string need not be maintained after this interface
|
|
completes execution. The output string of this interface should be
|
|
copied for non-ephemeral uses, because multiple implementation details
|
|
can cause asynchronous string deallocation. Furthermore, each
|
|
invocation of this interface can only read or write; simultaneous
|
|
read/write is not supported due to string lifetime limitations. The
|
|
name string must nil-terminated and comprised only of characters in the
|
|
sets recognized
|
|
by <citerefentry><refentrytitle>isgraph</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry> and
|
|
<citerefentry><refentrytitle>isblank</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry>.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="thread.prof.active">
|
|
<term>
|
|
<mallctl>thread.prof.active</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>rw</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Control whether sampling is currently active for the
|
|
calling thread. This is an activation mechanism in addition to <link
|
|
linkend="prof.active"><mallctl>prof.active</mallctl></link>; both must
|
|
be active for the calling thread to sample. This flag is enabled by
|
|
default.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="tcache.create">
|
|
<term>
|
|
<mallctl>tcache.create</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Create an explicit thread-specific cache (tcache) and
|
|
return an identifier that can be passed to the <link
|
|
linkend="MALLOCX_TCACHE"><constant>MALLOCX_TCACHE(<parameter>tc</parameter>)</constant></link>
|
|
macro to explicitly use the specified cache rather than the
|
|
automatically managed one that is used by default. Each explicit cache
|
|
can be used by only one thread at a time; the application must assure
|
|
that this constraint holds.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="tcache.flush">
|
|
<term>
|
|
<mallctl>tcache.flush</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>-w</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Flush the specified thread-specific cache (tcache). The
|
|
same considerations apply to this interface as to <link
|
|
linkend="thread.tcache.flush"><mallctl>thread.tcache.flush</mallctl></link>,
|
|
except that the tcache will never be automatically be discarded.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="tcache.destroy">
|
|
<term>
|
|
<mallctl>tcache.destroy</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>-w</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Flush the specified thread-specific cache (tcache) and
|
|
make the identifier available for use during a future tcache creation.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arena.i.purge">
|
|
<term>
|
|
<mallctl>arena.<i>.purge</mallctl>
|
|
(<type>void</type>)
|
|
<literal>--</literal>
|
|
</term>
|
|
<listitem><para>Purge unused dirty pages for arena <i>, or for
|
|
all arenas if <i> equals <link
|
|
linkend="arenas.narenas"><mallctl>arenas.narenas</mallctl></link>.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arena.i.dss">
|
|
<term>
|
|
<mallctl>arena.<i>.dss</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Set the precedence of dss allocation as related to mmap
|
|
allocation for arena <i>, or for all arenas if <i> equals
|
|
<link
|
|
linkend="arenas.narenas"><mallctl>arenas.narenas</mallctl></link>. See
|
|
<link linkend="opt.dss"><mallctl>opt.dss</mallctl></link> for supported
|
|
settings.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arena.i.lg_dirty_mult">
|
|
<term>
|
|
<mallctl>arena.<i>.lg_dirty_mult</mallctl>
|
|
(<type>ssize_t</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Current per-arena minimum ratio (log base 2) of active
|
|
to dirty pages for arena <i>. Each time this interface is set and
|
|
the ratio is increased, pages are synchronously purged as necessary to
|
|
impose the new ratio. See <link
|
|
linkend="opt.lg_dirty_mult"><mallctl>opt.lg_dirty_mult</mallctl></link>
|
|
for additional information.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arena.i.chunk.alloc">
|
|
<term>
|
|
<mallctl>arena.<i>.chunk.alloc</mallctl>
|
|
(<type>chunk_alloc_t *</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Get or set the chunk allocation function for arena
|
|
<i>. If setting, the chunk deallocation function should
|
|
also be set via <link linkend="arena.i.chunk.dalloc">
|
|
<mallctl>arena.<i>.chunk.dalloc</mallctl></link> to a companion
|
|
function that knows how to deallocate the chunks.
|
|
<funcsynopsis><funcprototype>
|
|
<funcdef>typedef void *<function>(chunk_alloc_t)</function></funcdef>
|
|
<paramdef>void *<parameter>chunk</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>size_t <parameter>alignment</parameter></paramdef>
|
|
<paramdef>bool *<parameter>zero</parameter></paramdef>
|
|
<paramdef>unsigned <parameter>arena_ind</parameter></paramdef>
|
|
</funcprototype></funcsynopsis>
|
|
A chunk allocation function conforms to the <type>chunk_alloc_t</type>
|
|
type and upon success returns a pointer to <parameter>size</parameter>
|
|
bytes of memory on behalf of arena <parameter>arena_ind</parameter> such
|
|
that the chunk's base address is a multiple of
|
|
<parameter>alignment</parameter>, as well as setting
|
|
<parameter>*zero</parameter> to indicate whether the chunk is zeroed.
|
|
Upon error the function returns <constant>NULL</constant> and leaves
|
|
<parameter>*zero</parameter> unmodified. The
|
|
<parameter>size</parameter> parameter is always a multiple of the chunk
|
|
size. The <parameter>alignment</parameter> parameter is always a power
|
|
of two at least as large as the chunk size. Zeroing is mandatory if
|
|
<parameter>*zero</parameter> is true upon function entry. If
|
|
<parameter>chunk</parameter> is not <constant>NULL</constant>, the
|
|
returned pointer must be <parameter>chunk</parameter> or
|
|
<constant>NULL</constant> if it could not be allocated.</para>
|
|
|
|
<para>Note that replacing the default chunk allocation function makes
|
|
the arena's <link
|
|
linkend="arena.i.dss"><mallctl>arena.<i>.dss</mallctl></link>
|
|
setting irrelevant.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arena.i.chunk.dalloc">
|
|
<term>
|
|
<mallctl>arena.<i>.chunk.dalloc</mallctl>
|
|
(<type>chunk_dalloc_t *</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Get or set the chunk deallocation function for arena
|
|
<i>. If setting, the chunk deallocation function must
|
|
be capable of deallocating all extant chunks associated with arena
|
|
<i>, usually by passing unknown chunks to the deallocation
|
|
function that was replaced. In practice, it is feasible to control
|
|
allocation for arenas created via <link
|
|
linkend="arenas.extend"><mallctl>arenas.extend</mallctl></link> such
|
|
that all chunks originate from an application-supplied chunk allocator
|
|
(by setting custom chunk allocation/deallocation/purge functions just
|
|
after arena creation), but the automatically created arenas may have
|
|
already created chunks prior to the application having an opportunity to
|
|
take over chunk allocation.
|
|
<funcsynopsis><funcprototype>
|
|
<funcdef>typedef bool <function>(chunk_dalloc_t)</function></funcdef>
|
|
<paramdef>void *<parameter>chunk</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
<paramdef>unsigned <parameter>arena_ind</parameter></paramdef>
|
|
</funcprototype></funcsynopsis>
|
|
A chunk deallocation function conforms to the
|
|
<type>chunk_dalloc_t</type> type and deallocates a
|
|
<parameter>chunk</parameter> of given <parameter>size</parameter> on
|
|
behalf of arena <parameter>arena_ind</parameter>, returning false upon
|
|
success.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arena.i.chunk.purge">
|
|
<term>
|
|
<mallctl>arena.<i>.chunk.purge</mallctl>
|
|
(<type>chunk_purge_t *</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Get or set the chunk purge function for arena <i>.
|
|
A chunk purge function optionally discards physical pages associated
|
|
with pages in the chunk's virtual memory range but leaves the virtual
|
|
memory mapping intact, and indicates via its return value whether pages
|
|
in the virtual memory range will be zero-filled the next time they are
|
|
accessed. If setting, the chunk purge function must be capable of
|
|
purging all extant chunks associated with arena <i>, usually by
|
|
passing unknown chunks to the purge function that was replaced. In
|
|
practice, it is feasible to control allocation for arenas created via
|
|
<link linkend="arenas.extend"><mallctl>arenas.extend</mallctl></link>
|
|
such that all chunks originate from an application-supplied chunk
|
|
allocator (by setting custom chunk allocation/deallocation/purge
|
|
functions just after arena creation), but the automatically created
|
|
arenas may have already created chunks prior to the application having
|
|
an opportunity to take over chunk allocation.
|
|
<funcsynopsis><funcprototype>
|
|
<funcdef>typedef bool <function>(chunk_purge_t)</function></funcdef>
|
|
<paramdef>void *<parameter>chunk</parameter></paramdef>
|
|
<paramdef>size_t <parameter>offset</parameter></paramdef>
|
|
<paramdef>size_t <parameter>length</parameter></paramdef>
|
|
<paramdef>unsigned <parameter>arena_ind</parameter></paramdef>
|
|
</funcprototype></funcsynopsis>
|
|
A chunk purge function conforms to the <type>chunk_purge_t</type> type
|
|
and purges pages within <parameter>chunk</parameter> at
|
|
<parameter>offset</parameter> bytes, extending for
|
|
<parameter>length</parameter> on behalf of arena
|
|
<parameter>arena_ind</parameter>, returning false if pages within the
|
|
purged virtual memory range will be zero-filled the next time they are
|
|
accessed. Note that the memory range being purged may span multiple
|
|
contiguous chunks, e.g. when purging memory that backed a huge
|
|
allocation.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.narenas">
|
|
<term>
|
|
<mallctl>arenas.narenas</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Current limit on number of arenas.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.initialized">
|
|
<term>
|
|
<mallctl>arenas.initialized</mallctl>
|
|
(<type>bool *</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>An array of <link
|
|
linkend="arenas.narenas"><mallctl>arenas.narenas</mallctl></link>
|
|
booleans. Each boolean indicates whether the corresponding arena is
|
|
initialized.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.lg_dirty_mult">
|
|
<term>
|
|
<mallctl>arenas.lg_dirty_mult</mallctl>
|
|
(<type>ssize_t</type>)
|
|
<literal>rw</literal>
|
|
</term>
|
|
<listitem><para>Current default per-arena minimum ratio (log base 2) of
|
|
active to dirty pages, used to initialize <link
|
|
linkend="arena.i.lg_dirty_mult"><mallctl>arena.<i>.lg_dirty_mult</mallctl></link>
|
|
during arena creation. See <link
|
|
linkend="opt.lg_dirty_mult"><mallctl>opt.lg_dirty_mult</mallctl></link>
|
|
for additional information.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.quantum">
|
|
<term>
|
|
<mallctl>arenas.quantum</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Quantum size.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.page">
|
|
<term>
|
|
<mallctl>arenas.page</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Page size.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.tcache_max">
|
|
<term>
|
|
<mallctl>arenas.tcache_max</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Maximum thread-cached size class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.nbins">
|
|
<term>
|
|
<mallctl>arenas.nbins</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Number of bin size classes.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.nhbins">
|
|
<term>
|
|
<mallctl>arenas.nhbins</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Total number of thread cache bin size
|
|
classes.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.bin.i.size">
|
|
<term>
|
|
<mallctl>arenas.bin.<i>.size</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Maximum size supported by size class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.bin.i.nregs">
|
|
<term>
|
|
<mallctl>arenas.bin.<i>.nregs</mallctl>
|
|
(<type>uint32_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Number of regions per page run.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.bin.i.run_size">
|
|
<term>
|
|
<mallctl>arenas.bin.<i>.run_size</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Number of bytes per page run.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.nlruns">
|
|
<term>
|
|
<mallctl>arenas.nlruns</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Total number of large size classes.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.lrun.i.size">
|
|
<term>
|
|
<mallctl>arenas.lrun.<i>.size</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Maximum size supported by this large size
|
|
class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.nhchunks">
|
|
<term>
|
|
<mallctl>arenas.nhchunks</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Total number of huge size classes.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.hchunks.i.size">
|
|
<term>
|
|
<mallctl>arenas.hchunks.<i>.size</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Maximum size supported by this huge size
|
|
class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="arenas.extend">
|
|
<term>
|
|
<mallctl>arenas.extend</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Extend the array of arenas by appending a new arena,
|
|
and returning the new arena index.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.thread_active_init">
|
|
<term>
|
|
<mallctl>prof.thread_active_init</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>rw</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Control the initial setting for <link
|
|
linkend="thread.prof.active"><mallctl>thread.prof.active</mallctl></link>
|
|
in newly created threads. See the <link
|
|
linkend="opt.prof_thread_active_init"><mallctl>opt.prof_thread_active_init</mallctl></link>
|
|
option for additional information.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.active">
|
|
<term>
|
|
<mallctl>prof.active</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>rw</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Control whether sampling is currently active. See the
|
|
<link
|
|
linkend="opt.prof_active"><mallctl>opt.prof_active</mallctl></link>
|
|
option for additional information, as well as the interrelated <link
|
|
linkend="thread.prof.active"><mallctl>thread.prof.active</mallctl></link>
|
|
mallctl.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.dump">
|
|
<term>
|
|
<mallctl>prof.dump</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>-w</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Dump a memory profile to the specified file, or if NULL
|
|
is specified, to a file according to the pattern
|
|
<filename><prefix>.<pid>.<seq>.m<mseq>.heap</filename>,
|
|
where <literal><prefix></literal> is controlled by the
|
|
<link
|
|
linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
|
|
option.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.gdump">
|
|
<term>
|
|
<mallctl>prof.gdump</mallctl>
|
|
(<type>bool</type>)
|
|
<literal>rw</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>When enabled, trigger a memory profile dump every time
|
|
the total virtual memory exceeds the previous maximum. Profiles are
|
|
dumped to files named according to the pattern
|
|
<filename><prefix>.<pid>.<seq>.u<useq>.heap</filename>,
|
|
where <literal><prefix></literal> is controlled by the <link
|
|
linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
|
|
option.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.reset">
|
|
<term>
|
|
<mallctl>prof.reset</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>-w</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Reset all memory profile statistics, and optionally
|
|
update the sample rate (see <link
|
|
linkend="opt.lg_prof_sample"><mallctl>opt.lg_prof_sample</mallctl></link>
|
|
and <link
|
|
linkend="prof.lg_sample"><mallctl>prof.lg_sample</mallctl></link>).
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.lg_sample">
|
|
<term>
|
|
<mallctl>prof.lg_sample</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Get the current sample rate (see <link
|
|
linkend="opt.lg_prof_sample"><mallctl>opt.lg_prof_sample</mallctl></link>).
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="prof.interval">
|
|
<term>
|
|
<mallctl>prof.interval</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-prof</option>]
|
|
</term>
|
|
<listitem><para>Average number of bytes allocated between
|
|
inverval-based profile dumps. See the
|
|
<link
|
|
linkend="opt.lg_prof_interval"><mallctl>opt.lg_prof_interval</mallctl></link>
|
|
option for additional information.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.cactive">
|
|
<term>
|
|
<mallctl>stats.cactive</mallctl>
|
|
(<type>size_t *</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Pointer to a counter that contains an approximate count
|
|
of the current number of bytes in active pages. The estimate may be
|
|
high, but never low, because each arena rounds up when computing its
|
|
contribution to the counter. Note that the <link
|
|
linkend="epoch"><mallctl>epoch</mallctl></link> mallctl has no bearing
|
|
on this counter. Furthermore, counter consistency is maintained via
|
|
atomic operations, so it is necessary to use an atomic operation in
|
|
order to guarantee a consistent read when dereferencing the pointer.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.allocated">
|
|
<term>
|
|
<mallctl>stats.allocated</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Total number of bytes allocated by the
|
|
application.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.active">
|
|
<term>
|
|
<mallctl>stats.active</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Total number of bytes in active pages allocated by the
|
|
application. This is a multiple of the page size, and greater than or
|
|
equal to <link
|
|
linkend="stats.allocated"><mallctl>stats.allocated</mallctl></link>.
|
|
This does not include <link linkend="stats.arenas.i.pdirty">
|
|
<mallctl>stats.arenas.<i>.pdirty</mallctl></link>, nor pages
|
|
entirely devoted to allocator metadata.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.metadata">
|
|
<term>
|
|
<mallctl>stats.metadata</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Total number of bytes dedicated to metadata, which
|
|
comprise base allocations used for bootstrap-sensitive internal
|
|
allocator data structures, arena chunk headers (see <link
|
|
linkend="stats.arenas.i.metadata.mapped"><mallctl>stats.arenas.<i>.metadata.mapped</mallctl></link>),
|
|
and internal allocations (see <link
|
|
linkend="stats.arenas.i.metadata.allocated"><mallctl>stats.arenas.<i>.metadata.allocated</mallctl></link>).</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.mapped">
|
|
<term>
|
|
<mallctl>stats.mapped</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Total number of bytes in chunks mapped on behalf of the
|
|
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.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.dss">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.dss</mallctl>
|
|
(<type>const char *</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>dss (<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry>) allocation precedence as
|
|
related to <citerefentry><refentrytitle>mmap</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry> allocation. See <link
|
|
linkend="opt.dss"><mallctl>opt.dss</mallctl></link> for details.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.nthreads">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.nthreads</mallctl>
|
|
(<type>unsigned</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Number of threads currently assigned to
|
|
arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.pactive">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.pactive</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Number of pages in active runs.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.pdirty">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.pdirty</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
</term>
|
|
<listitem><para>Number of pages within unused runs that are potentially
|
|
dirty, and for which <function>madvise<parameter>...</parameter>
|
|
<parameter><constant>MADV_DONTNEED</constant></parameter></function> or
|
|
similar has not been called.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.mapped">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.mapped</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of mapped bytes.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.metadata.mapped">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.metadata.mapped</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of mapped bytes in arena chunk headers, which
|
|
track the states of the non-metadata pages.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.metadata.allocated">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.metadata.allocated</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of bytes dedicated to internal allocations.
|
|
Internal allocations differ from application-originated allocations in
|
|
that they are for internal use, and that they are omitted from heap
|
|
profiles. This statistic is reported separately from <link
|
|
linkend="stats.metadata"><mallctl>stats.metadata</mallctl></link> and
|
|
<link
|
|
linkend="stats.arenas.i.metadata.mapped"><mallctl>stats.arenas.<i>.metadata.mapped</mallctl></link>
|
|
because it overlaps with e.g. the <link
|
|
linkend="stats.allocated"><mallctl>stats.allocated</mallctl></link> and
|
|
<link linkend="stats.active"><mallctl>stats.active</mallctl></link>
|
|
statistics, whereas the other metadata statistics do
|
|
not.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.npurge">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.npurge</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of dirty page purge sweeps performed.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.nmadvise">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.nmadvise</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of <function>madvise<parameter>...</parameter>
|
|
<parameter><constant>MADV_DONTNEED</constant></parameter></function> or
|
|
similar calls made to purge dirty pages.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.purged">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.purged</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of pages purged.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.small.allocated">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.small.allocated</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of bytes currently allocated by small objects.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.small.nmalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.small.nmalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocation requests served by
|
|
small bins.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.small.ndalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.small.ndalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of small objects returned to bins.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.small.nrequests">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.small.nrequests</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of small allocation requests.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.large.allocated">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.large.allocated</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of bytes currently allocated by large objects.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.large.nmalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.large.nmalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of large allocation requests served
|
|
directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.large.ndalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.large.ndalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of large deallocation requests served
|
|
directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.large.nrequests">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.large.nrequests</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of large allocation requests.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.huge.allocated">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.huge.allocated</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Number of bytes currently allocated by huge objects.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.huge.nmalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.huge.nmalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of huge allocation requests served
|
|
directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.huge.ndalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.huge.ndalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of huge deallocation requests served
|
|
directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.huge.nrequests">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.huge.nrequests</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of huge allocation requests.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nmalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.nmalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocations served by bin.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.ndalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.ndalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocations returned to bin.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nrequests">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.nrequests</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocation
|
|
requests.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.curregs">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.curregs</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Current number of regions for this size
|
|
class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nfills">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.nfills</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option> <option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of tcache fills.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nflushes">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.nflushes</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option> <option>--enable-tcache</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of tcache flushes.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nruns">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.nruns</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of runs created.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nreruns">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.nreruns</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of times the current run from which
|
|
to allocate changed.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.bins.j.curruns">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.bins.<j>.curruns</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Current number of runs.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.nmalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.lruns.<j>.nmalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocation requests for this size
|
|
class served directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.ndalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.lruns.<j>.ndalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of deallocation requests for this
|
|
size class served directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.nrequests">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.lruns.<j>.nrequests</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocation requests for this size
|
|
class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.curruns">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.lruns.<j>.curruns</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Current number of runs for this size class.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.hchunks.j.nmalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.hchunks.<j>.nmalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocation requests for this size
|
|
class served directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.hchunks.j.ndalloc">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.hchunks.<j>.ndalloc</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of deallocation requests for this
|
|
size class served directly by the arena.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.hchunks.j.nrequests">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.hchunks.<j>.nrequests</mallctl>
|
|
(<type>uint64_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Cumulative number of allocation requests for this size
|
|
class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="stats.arenas.i.hchunks.j.curhchunks">
|
|
<term>
|
|
<mallctl>stats.arenas.<i>.hchunks.<j>.curhchunks</mallctl>
|
|
(<type>size_t</type>)
|
|
<literal>r-</literal>
|
|
[<option>--enable-stats</option>]
|
|
</term>
|
|
<listitem><para>Current number of huge allocations for this size class.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
<refsect1 id="debugging_malloc_problems">
|
|
<title>DEBUGGING MALLOC PROBLEMS</title>
|
|
<para>When debugging, it is a good idea to configure/build jemalloc with
|
|
the <option>--enable-debug</option> and <option>--enable-fill</option>
|
|
options, and recompile the program with suitable options and symbols for
|
|
debugger support. When so configured, jemalloc incorporates a wide variety
|
|
of run-time assertions that catch application errors such as double-free,
|
|
write-after-free, etc.</para>
|
|
|
|
<para>Programs often accidentally depend on “uninitialized”
|
|
memory actually being filled with zero bytes. Junk filling
|
|
(see the <link linkend="opt.junk"><mallctl>opt.junk</mallctl></link>
|
|
option) tends to expose such bugs in the form of obviously incorrect
|
|
results and/or coredumps. Conversely, zero
|
|
filling (see the <link
|
|
linkend="opt.zero"><mallctl>opt.zero</mallctl></link> option) eliminates
|
|
the symptoms of such bugs. Between these two options, it is usually
|
|
possible to quickly detect, diagnose, and eliminate such bugs.</para>
|
|
|
|
<para>This implementation does not provide much detail about the problems
|
|
it detects, because the performance impact for storing such information
|
|
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.</para>
|
|
</refsect1>
|
|
<refsect1 id="diagnostic_messages">
|
|
<title>DIAGNOSTIC MESSAGES</title>
|
|
<para>If any of the memory allocation/deallocation functions detect an
|
|
error or warning condition, a message will be printed to file descriptor
|
|
<constant>STDERR_FILENO</constant>. Errors will result in the process
|
|
dumping core. If the <link
|
|
linkend="opt.abort"><mallctl>opt.abort</mallctl></link> option is set, most
|
|
warnings are treated as errors.</para>
|
|
|
|
<para>The <varname>malloc_message</varname> variable allows the programmer
|
|
to override the function which emits the text strings forming the errors
|
|
and warnings if for some reason the <constant>STDERR_FILENO</constant> file
|
|
descriptor is not suitable for this.
|
|
<function>malloc_message<parameter/></function> takes the
|
|
<parameter>cbopaque</parameter> pointer argument that is
|
|
<constant>NULL</constant> unless overridden by the arguments in a call to
|
|
<function>malloc_stats_print<parameter/></function>, followed by a string
|
|
pointer. Please note that doing anything which tries to allocate memory in
|
|
this function is likely to result in a crash or deadlock.</para>
|
|
|
|
<para>All messages are prefixed by
|
|
“<computeroutput><jemalloc>: </computeroutput>”.</para>
|
|
</refsect1>
|
|
<refsect1 id="return_values">
|
|
<title>RETURN VALUES</title>
|
|
<refsect2>
|
|
<title>Standard API</title>
|
|
<para>The <function>malloc<parameter/></function> and
|
|
<function>calloc<parameter/></function> functions return a pointer to the
|
|
allocated memory if successful; otherwise a <constant>NULL</constant>
|
|
pointer is returned and <varname>errno</varname> is set to
|
|
<errorname>ENOMEM</errorname>.</para>
|
|
|
|
<para>The <function>posix_memalign<parameter/></function> function
|
|
returns the value 0 if successful; otherwise it returns an error value.
|
|
The <function>posix_memalign<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 at least as large as
|
|
<code language="C">sizeof(<type>void *</type>)</code>.
|
|
</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorname>ENOMEM</errorname></term>
|
|
|
|
<listitem><para>Memory allocation error.</para></listitem>
|
|
</varlistentry>
|
|
</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>
|
|
pointer is returned, and <varname>errno</varname> is set to
|
|
<errorname>ENOMEM</errorname> if the error was the result of an
|
|
allocation failure. The <function>realloc<parameter/></function>
|
|
function always leaves the original buffer intact when an error occurs.
|
|
</para>
|
|
|
|
<para>The <function>free<parameter/></function> function returns no
|
|
value.</para>
|
|
</refsect2>
|
|
<refsect2>
|
|
<title>Non-standard API</title>
|
|
<para>The <function>mallocx<parameter/></function> and
|
|
<function>rallocx<parameter/></function> functions return a pointer to
|
|
the allocated memory if successful; otherwise a <constant>NULL</constant>
|
|
pointer is returned to indicate insufficient contiguous memory was
|
|
available to service the allocation request. </para>
|
|
|
|
<para>The <function>xallocx<parameter/></function> function returns the
|
|
real size of the resulting resized allocation pointed to by
|
|
<parameter>ptr</parameter>, which is a value less than
|
|
<parameter>size</parameter> if the allocation could not be adequately
|
|
grown in place. </para>
|
|
|
|
<para>The <function>sallocx<parameter/></function> function returns the
|
|
real size of the allocation pointed to by <parameter>ptr</parameter>.
|
|
</para>
|
|
|
|
<para>The <function>nallocx<parameter/></function> returns the real size
|
|
that would result from a successful equivalent
|
|
<function>mallocx<parameter/></function> function call, or zero if
|
|
insufficient memory is available to perform the size computation. </para>
|
|
|
|
<para>The <function>mallctl<parameter/></function>,
|
|
<function>mallctlnametomib<parameter/></function>, and
|
|
<function>mallctlbymib<parameter/></function> functions return 0 on
|
|
success; otherwise they return an error value. The functions will fail
|
|
if:
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorname>EINVAL</errorname></term>
|
|
|
|
<listitem><para><parameter>newp</parameter> is not
|
|
<constant>NULL</constant>, and <parameter>newlen</parameter> is too
|
|
large or too small. Alternatively, <parameter>*oldlenp</parameter>
|
|
is too large or too small; in this case as much data as possible
|
|
are read despite the error.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorname>ENOENT</errorname></term>
|
|
|
|
<listitem><para><parameter>name</parameter> or
|
|
<parameter>mib</parameter> specifies an unknown/invalid
|
|
value.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorname>EPERM</errorname></term>
|
|
|
|
<listitem><para>Attempt to read or write void value, or attempt to
|
|
write read-only value.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorname>EAGAIN</errorname></term>
|
|
|
|
<listitem><para>A memory allocation failure
|
|
occurred.</para></listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorname>EFAULT</errorname></term>
|
|
|
|
<listitem><para>An interface with side effects failed in some way
|
|
not directly related to <function>mallctl*<parameter/></function>
|
|
read/write processing.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</para>
|
|
|
|
<para>The <function>malloc_usable_size<parameter/></function> function
|
|
returns the usable size of the allocation pointed to by
|
|
<parameter>ptr</parameter>. </para>
|
|
</refsect2>
|
|
</refsect1>
|
|
<refsect1 id="environment">
|
|
<title>ENVIRONMENT</title>
|
|
<para>The following environment variable affects the execution of the
|
|
allocation functions:
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><envar>MALLOC_CONF</envar></term>
|
|
|
|
<listitem><para>If the environment variable
|
|
<envar>MALLOC_CONF</envar> is set, the characters it contains
|
|
will be interpreted as options.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="examples">
|
|
<title>EXAMPLES</title>
|
|
<para>To dump core whenever a problem occurs:
|
|
<screen>ln -s 'abort:true' /etc/malloc.conf</screen>
|
|
</para>
|
|
<para>To specify in the source a chunk size that is 16 MiB:
|
|
<programlisting language="C"><![CDATA[
|
|
malloc_conf = "lg_chunk:24";]]></programlisting></para>
|
|
</refsect1>
|
|
<refsect1 id="see_also">
|
|
<title>SEE ALSO</title>
|
|
<para><citerefentry><refentrytitle>madvise</refentrytitle>
|
|
<manvolnum>2</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>mmap</refentrytitle>
|
|
<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>
|
|
<manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>getpagesize</refentrytitle>
|
|
<manvolnum>3</manvolnum></citerefentry></para>
|
|
</refsect1>
|
|
<refsect1 id="standards">
|
|
<title>STANDARDS</title>
|
|
<para>The <function>malloc<parameter/></function>,
|
|
<function>calloc<parameter/></function>,
|
|
<function>realloc<parameter/></function>, and
|
|
<function>free<parameter/></function> functions conform to ISO/IEC
|
|
9899:1990 (“ISO C90”).</para>
|
|
|
|
<para>The <function>posix_memalign<parameter/></function> function conforms
|
|
to IEEE Std 1003.1-2001 (“POSIX.1”).</para>
|
|
</refsect1>
|
|
</refentry>
|