2010-11-25 14:00:02 +08:00
|
|
|
<?xml version='1.0' encoding='UTF-8'?>
|
|
|
|
<?xml-stylesheet type="text/xsl"
|
|
|
|
href="http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl"?>
|
|
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
|
|
|
|
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
|
|
|
|
]>
|
|
|
|
|
|
|
|
<refentry>
|
|
|
|
<refentryinfo>
|
|
|
|
<title>User Manual</title>
|
|
|
|
<productname>jemalloc</productname>
|
|
|
|
<releaseinfo role="version">@jemalloc_version@</releaseinfo>
|
|
|
|
<authorgroup>
|
|
|
|
<author>
|
|
|
|
<firstname>Jason</firstname>
|
|
|
|
<surname>Evans</surname>
|
|
|
|
<personblurb>Author</personblurb>
|
|
|
|
</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>
|
2012-03-14 03:55:21 +08:00
|
|
|
<refname>aligned_alloc</refname>
|
2010-11-25 14:00:02 +08:00
|
|
|
<refname>realloc</refname>
|
|
|
|
<refname>free</refname>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<refname>mallocx</refname>
|
|
|
|
<refname>rallocx</refname>
|
|
|
|
<refname>xallocx</refname>
|
|
|
|
<refname>sallocx</refname>
|
|
|
|
<refname>dallocx</refname>
|
2014-08-29 03:41:48 +08:00
|
|
|
<refname>sdallocx</refname>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<refname>nallocx</refname>
|
2010-11-25 14:00:02 +08:00
|
|
|
<refname>mallctl</refname>
|
|
|
|
<refname>mallctlnametomib</refname>
|
|
|
|
<refname>mallctlbymib</refname>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<refname>malloc_stats_print</refname>
|
|
|
|
<refname>malloc_usable_size</refname>
|
2010-11-25 14:00:02 +08:00
|
|
|
-->
|
|
|
|
<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>
|
2014-10-06 03:05:37 +08:00
|
|
|
<funcsynopsisinfo>#include <<filename class="headerfile">jemalloc/jemalloc.h</filename>></funcsynopsisinfo>
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
2012-03-14 03:55:21 +08:00
|
|
|
<funcprototype>
|
|
|
|
<funcdef>void *<function>aligned_alloc</function></funcdef>
|
|
|
|
<paramdef>size_t <parameter>alignment</parameter></paramdef>
|
|
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
|
|
</funcprototype>
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<funcdef>void *<function>mallocx</function></funcdef>
|
|
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
2010-11-25 14:00:02 +08:00
|
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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>
|
2014-08-29 03:41:48 +08:00
|
|
|
<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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<funcprototype>
|
|
|
|
<funcdef>size_t <function>nallocx</function></funcdef>
|
|
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
|
|
<paramdef>int <parameter>flags</parameter></paramdef>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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>
|
2010-11-25 14:00:02 +08:00
|
|
|
<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
|
2014-05-16 13:46:24 +08:00
|
|
|
allocation's base address is a multiple of
|
2010-11-25 14:00:02 +08:00
|
|
|
<parameter>alignment</parameter>, and returns the allocation in the value
|
|
|
|
pointed to by <parameter>ptr</parameter>. The requested
|
2014-05-16 13:46:24 +08:00
|
|
|
<parameter>alignment</parameter> must be a power of 2 at least as large as
|
|
|
|
<code language="C">sizeof(<type>void *</type>)</code>.</para>
|
2010-11-25 14:00:02 +08:00
|
|
|
|
2012-03-14 03:55:21 +08:00
|
|
|
<para>The <function>aligned_alloc<parameter/></function> function
|
|
|
|
allocates <parameter>size</parameter> bytes of memory such that the
|
2014-05-16 13:46:24 +08:00
|
|
|
allocation's base address is a multiple of
|
2012-03-14 03:55:21 +08:00
|
|
|
<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>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<para>The <function>mallocx<parameter/></function>,
|
|
|
|
<function>rallocx<parameter/></function>,
|
|
|
|
<function>xallocx<parameter/></function>,
|
|
|
|
<function>sallocx<parameter/></function>,
|
2014-08-29 03:41:48 +08:00
|
|
|
<function>dallocx<parameter/></function>,
|
|
|
|
<function>sdallocx<parameter/></function>, and
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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>
|
|
|
|
<term><constant>MALLOCX_LG_ALIGN(<parameter>la</parameter>)
|
|
|
|
</constant></term>
|
2010-11-25 14:00:02 +08:00
|
|
|
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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>
|
|
|
|
<term><constant>MALLOCX_ALIGN(<parameter>a</parameter>)
|
|
|
|
</constant></term>
|
2010-11-25 14:00:02 +08:00
|
|
|
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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>
|
|
|
|
<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>
|
|
|
|
<term><constant>MALLOCX_ARENA(<parameter>a</parameter>)
|
|
|
|
</constant></term>
|
|
|
|
|
|
|
|
<listitem><para>Use the arena specified by the index
|
|
|
|
<parameter>a</parameter> (and by necessity bypass the thread
|
2014-04-15 13:38:59 +08:00
|
|
|
cache). 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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
</varlistentry>
|
|
|
|
</variablelist>
|
2010-11-25 14:00:02 +08:00
|
|
|
</para>
|
|
|
|
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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
|
2014-01-13 07:05:44 +08:00
|
|
|
<parameter>size</parameter> is <constant>0</constant>, or if request size
|
|
|
|
overflows due to size class and/or alignment constraints.</para>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
|
|
|
|
<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
|
2014-01-13 07:05:44 +08:00
|
|
|
<parameter>size</parameter> is <constant>0</constant>, or if request size
|
|
|
|
overflows due to size class and/or alignment constraints.</para>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
|
|
|
|
<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>
|
|
|
|
|
2014-08-29 03:41:48 +08:00
|
|
|
<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>
|
|
|
|
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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
|
2014-01-13 07:05:44 +08:00
|
|
|
undefined if <parameter>size</parameter> is <constant>0</constant>, or if
|
|
|
|
request size overflows due to size class and/or alignment
|
|
|
|
constraints.</para>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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;
|
2013-12-19 15:21:42 +08:00
|
|
|
size_t mib[4];
|
2010-11-25 14:00:02 +08:00
|
|
|
size_t len, miblen;
|
|
|
|
|
|
|
|
len = sizeof(nbins);
|
|
|
|
mallctl("arenas.nbins", &nbins, &len, NULL, 0);
|
|
|
|
|
|
|
|
miblen = 4;
|
2013-12-19 15:21:42 +08:00
|
|
|
mallctlnametomib("arenas.bin.0.size", mib, &miblen);
|
2010-11-25 14:00:02 +08:00
|
|
|
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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
|
|
|
|
<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” and “l” can be specified to omit per size
|
|
|
|
class statistics for bins and large 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>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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
|
2013-03-20 07:28:41 +08:00
|
|
|
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>
|
2010-11-25 14:00:02 +08:00
|
|
|
|
|
|
|
<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
|
2014-04-16 03:09:48 +08:00
|
|
|
<citerefentry><refentrytitle>sbrk</refentrytitle>
|
|
|
|
<manvolnum>2</manvolnum></citerefentry> is supported by the operating
|
|
|
|
system, this allocator uses both
|
|
|
|
<citerefentry><refentrytitle>mmap</refentrytitle>
|
2010-11-25 14:00:02 +08:00
|
|
|
<manvolnum>2</manvolnum></citerefentry> and
|
2012-04-22 04:33:48 +08:00
|
|
|
<citerefentry><refentrytitle>sbrk</refentrytitle>
|
2010-11-25 14:00:02 +08:00
|
|
|
<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 objects are smaller than one page. Large
|
|
|
|
objects are smaller than the chunk size. Huge objects are a multiple of
|
2014-05-16 13:22:27 +08:00
|
|
|
the chunk size. 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>
|
2010-11-25 14:00:02 +08:00
|
|
|
|
|
|
|
<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
|
2012-02-14 06:30:52 +08:00
|
|
|
a frontier and free list to track which regions are in use. Allocation
|
|
|
|
requests that are no more than half the quantum (8 or 16, depending on
|
|
|
|
architecture) are rounded up to the nearest power of two that is at least
|
2012-02-29 08:50:47 +08:00
|
|
|
<code language="C">sizeof(<type>double</type>)</code>. All other small
|
|
|
|
object size classes are multiples of the quantum, spaced such that internal
|
|
|
|
fragmentation is limited to approximately 25% for all but the smallest size
|
|
|
|
classes. Allocation requests that are larger than the maximum small size
|
|
|
|
class, but small enough to fit in an arena-managed chunk (see the <link
|
2010-11-25 14:00:02 +08:00
|
|
|
linkend="opt.lg_chunk"><mallctl>opt.lg_chunk</mallctl></link> option), are
|
|
|
|
rounded up to the nearest run size. Allocation requests that are too large
|
|
|
|
to fit in an arena-managed chunk are rounded up to the nearest multiple of
|
|
|
|
the chunk 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>Assuming 4 MiB 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>
|
2012-03-20 00:36:44 +08:00
|
|
|
<tgroup cols="3" colsep="1" rowsep="1">
|
|
|
|
<colspec colname="c1" align="left"/>
|
|
|
|
<colspec colname="c2" align="right"/>
|
|
|
|
<colspec colname="c3" align="left"/>
|
2010-11-25 14:00:02 +08:00
|
|
|
<thead>
|
|
|
|
<row>
|
|
|
|
<entry>Category</entry>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>Spacing</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
<entry>Size</entry>
|
|
|
|
</row>
|
|
|
|
</thead>
|
|
|
|
<tbody>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry morerows="6">Small</entry>
|
|
|
|
<entry>lg</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
<entry>[8]</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>16</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
<entry>[16, 32, 48, ..., 128]</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>32</entry>
|
2012-02-29 08:50:47 +08:00
|
|
|
<entry>[160, 192, 224, 256]</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>64</entry>
|
2012-02-29 08:50:47 +08:00
|
|
|
<entry>[320, 384, 448, 512]</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>128</entry>
|
2012-02-29 08:50:47 +08:00
|
|
|
<entry>[640, 768, 896, 1024]</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>256</entry>
|
2012-02-29 08:50:47 +08:00
|
|
|
<entry>[1280, 1536, 1792, 2048]</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>512</entry>
|
2012-02-29 08:50:47 +08:00
|
|
|
<entry>[2560, 3072, 3584]</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>Large</entry>
|
|
|
|
<entry>4 KiB</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
<entry>[4 KiB, 8 KiB, 12 KiB, ..., 4072 KiB]</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
2012-03-20 00:36:44 +08:00
|
|
|
<entry>Huge</entry>
|
|
|
|
<entry>4 MiB</entry>
|
2010-11-25 14:00:02 +08:00
|
|
|
<entry>[4 MiB, 8 MiB, 12 MiB, ...]</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>
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="version">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.debug">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.fill">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.lazy_lock">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.munmap">
|
2012-04-17 08:52:27 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.prof">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.prof_libgcc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.prof_libunwind">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.stats">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.tcache">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.tls">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.utrace">
|
2012-04-06 04:36:17 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.valgrind">
|
2012-04-06 15:35:09 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="config.xmalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2012-10-12 04:53:15 +08:00
|
|
|
<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
|
2014-04-16 03:09:48 +08:00
|
|
|
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.
|
2013-12-20 13:40:41 +08:00
|
|
|
</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 4 MiB (2^22).
|
|
|
|
</para></listitem>
|
2012-10-12 04:53:15 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<varlistentry id="opt.narenas">
|
|
|
|
<term>
|
|
|
|
<mallctl>opt.narenas</mallctl>
|
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
</term>
|
2012-10-12 04:53:15 +08:00
|
|
|
<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>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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
|
2012-10-31 06:42:37 +08:00
|
|
|
default minimum ratio is 8:1 (2^3:1); an option value of -1 will
|
2010-11-25 14:00:02 +08:00
|
|
|
disable dirty page purging.</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. 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>bool</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-fill</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Junk filling enabled/disabled. If enabled, each byte
|
|
|
|
of uninitialized allocated memory will be initialized to
|
|
|
|
<literal>0xa5</literal>. All deallocated memory will be initialized to
|
|
|
|
<literal>0x5a</literal>. This is intended for debugging and will
|
|
|
|
impact performance negatively. This option is disabled by default
|
|
|
|
unless <option>--enable-debug</option> is specified during
|
2012-05-16 05:48:14 +08:00
|
|
|
configuration, in which case it is enabled by default unless running
|
|
|
|
inside <ulink
|
|
|
|
url="http://valgrind.org/">Valgrind</ulink>.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2012-04-06 15:35:09 +08:00
|
|
|
<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
|
2012-04-26 14:17:57 +08:00
|
|
|
url="http://valgrind.org/">Valgrind</ulink>, which can detect attempts
|
|
|
|
to access quarantined objects. This is intended for debugging and will
|
2012-05-16 05:48:14 +08:00
|
|
|
impact performance negatively. The default quarantine size is 0 unless
|
|
|
|
running inside Valgrind, in which case the default is 16
|
|
|
|
MiB.</para></listitem>
|
2012-04-06 15:35:09 +08:00
|
|
|
</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
|
2012-04-26 14:17:57 +08:00
|
|
|
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
|
2012-05-16 05:48:14 +08:00
|
|
|
default unless running inside Valgrind.</para></listitem>
|
2012-04-06 15:35:09 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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
|
2014-04-15 13:32:31 +08:00
|
|
|
<function>realloc<parameter/></function> and
|
|
|
|
<function>rallocx<parameter/></function> calls do not zero memory that
|
2010-11-25 14:00:02 +08:00
|
|
|
was previously allocated. This is intended for debugging and will
|
|
|
|
impact performance negatively. This option is disabled by default.
|
|
|
|
</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2012-04-06 04:36:17 +08:00
|
|
|
<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>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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 enabled/disabled. When there
|
|
|
|
are multiple threads, each thread uses a thread-specific cache 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>
|
2012-03-06 06:34:37 +08:00
|
|
|
option for related tuning information. This option is enabled by
|
2012-05-16 14:31:53 +08:00
|
|
|
default unless running inside <ulink
|
2014-04-16 07:35:08 +08:00
|
|
|
url="http://valgrind.org/">Valgrind</ulink>, in which case it is
|
|
|
|
forcefully disabled.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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. 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
|
2012-04-18 07:39:33 +08:00
|
|
|
memory allocation activity. See the <link
|
2010-11-25 14:00:02 +08:00
|
|
|
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>
|
2012-04-18 07:39:33 +08:00
|
|
|
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
|
2010-11-25 14:00:02 +08:00
|
|
|
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>)
|
2013-12-20 13:40:41 +08:00
|
|
|
<literal>rw</literal>
|
2010-11-25 14:00:02 +08:00
|
|
|
[<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>
|
|
|
|
|
2014-10-04 14:25:30 +08:00
|
|
|
<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>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<varlistentry id="opt.lg_prof_sample">
|
|
|
|
<term>
|
|
|
|
<mallctl>opt.lg_prof_sample</mallctl>
|
2014-08-19 07:22:13 +08:00
|
|
|
(<type>size_t</type>)
|
2010-11-25 14:00:02 +08:00
|
|
|
<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
|
2012-04-18 07:39:33 +08:00
|
|
|
computational overhead. The default sample interval is 512 KiB (2^19
|
|
|
|
B).</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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
|
2012-04-18 07:39:33 +08:00
|
|
|
cumulative counts are not always of interest. This option is disabled
|
2012-02-14 10:04:26 +08:00
|
|
|
by default.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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>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. This option is disabled by default.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2012-04-18 07:39:33 +08:00
|
|
|
<varlistentry id="opt.prof_final">
|
|
|
|
<term>
|
|
|
|
<mallctl>opt.prof_final</mallctl>
|
|
|
|
(<type>bool</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-prof</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Use an
|
|
|
|
<citerefentry><refentrytitle>atexit</refentrytitle>
|
|
|
|
<manvolnum>3</manvolnum></citerefentry> function to dump final memory
|
|
|
|
usage to a file named according to the pattern
|
|
|
|
<filename><prefix>.<pid>.<seq>.f.heap</filename>,
|
|
|
|
where <literal><prefix></literal> is controlled by the <link
|
|
|
|
linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
|
|
|
|
option. This option is enabled by default.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="thread.arena">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>thread.arena</mallctl>
|
|
|
|
(<type>unsigned</type>)
|
|
|
|
<literal>rw</literal>
|
|
|
|
</term>
|
|
|
|
<listitem><para>Get or set the arena associated with the calling
|
2012-10-12 04:53:15 +08:00
|
|
|
thread. If the specified arena was not initialized beforehand (see the
|
|
|
|
<link
|
2010-11-25 14:00:02 +08:00
|
|
|
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>
|
|
|
|
|
2010-12-04 07:55:47 +08:00
|
|
|
<varlistentry id="thread.allocated">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="thread.allocatedp">
|
2010-12-04 07:55:47 +08:00
|
|
|
<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">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="thread.deallocatedp">
|
2010-12-04 07:55:47 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="thread.tcache.enabled">
|
2012-03-27 09:54:44 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>thread.tcache.enabled</mallctl>
|
|
|
|
(<type>bool</type>)
|
|
|
|
<literal>rw</literal>
|
|
|
|
[<option>--enable-tcache</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Enable/disable calling thread's tcache. The tcache is
|
|
|
|
implicitly flushed as a side effect of becoming
|
|
|
|
disabled (see <link
|
|
|
|
lenkend="thread.tcache.flush"><mallctl>thread.tcache.flush</mallctl></link>).
|
|
|
|
</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="thread.tcache.flush">
|
2012-03-17 08:09:32 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>thread.tcache.flush</mallctl>
|
|
|
|
(<type>void</type>)
|
|
|
|
<literal>--</literal>
|
|
|
|
[<option>--enable-tcache</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Flush calling thread's tcache. This interface releases
|
|
|
|
all cached objects and internal data structures associated with the
|
|
|
|
calling thread's thread-specific cache. Ordinarily, this interface
|
|
|
|
need not be called, since automatic periodic incremental garbage
|
|
|
|
collection occurs, and the thread cache is automatically discarded when
|
|
|
|
a thread exits. However, garbage collection is triggered by allocation
|
|
|
|
activity, so it is possible for a thread that stops
|
|
|
|
allocating/deallocating to retain its cache indefinitely, in which case
|
|
|
|
the developer may find manual flushing useful.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2014-08-19 07:22:13 +08:00
|
|
|
<varlistentry id="thread.prof.name">
|
|
|
|
<term>
|
|
|
|
<mallctl>thread.prof.name</mallctl>
|
|
|
|
(<type>const char *</type>)
|
2014-10-04 14:25:30 +08:00
|
|
|
<literal>r-</literal> or
|
|
|
|
<literal>-w</literal>
|
2014-08-19 07:22:13 +08:00
|
|
|
[<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
|
2014-10-04 14:25:30 +08:00
|
|
|
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>
|
2014-08-19 07:22:13 +08:00
|
|
|
</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
|
2014-10-04 14:25:30 +08:00
|
|
|
calling thread. This is an activation mechanism in addition to <link
|
2014-08-19 07:22:13 +08:00
|
|
|
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>
|
|
|
|
|
2012-10-12 04:53:15 +08:00
|
|
|
<varlistentry id="arena.i.purge">
|
|
|
|
<term>
|
|
|
|
<mallctl>arena.<i>.purge</mallctl>
|
2014-04-16 03:46:28 +08:00
|
|
|
(<type>void</type>)
|
2012-10-12 04:53:15 +08:00
|
|
|
<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
|
2014-05-16 13:22:27 +08:00
|
|
|
linkend="arenas.narenas"><mallctl>arenas.narenas</mallctl></link>. See
|
|
|
|
<link linkend="opt.dss"><mallctl>opt.dss</mallctl></link> for supported
|
|
|
|
settings.</para></listitem>
|
2012-10-12 04:53:15 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2014-05-06 06:16:56 +08:00
|
|
|
<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
|
2014-05-16 13:22:27 +08:00
|
|
|
also be set via <link linkend="arena.i.chunk.dalloc">
|
|
|
|
<mallctl>arena.<i>.chunk.dalloc</mallctl></link> to a companion
|
2014-05-06 06:16:56 +08:00
|
|
|
function that knows how to deallocate the chunks.
|
2014-10-06 05:48:44 +08:00
|
|
|
<funcsynopsis><funcprototype>
|
2014-05-06 06:16:56 +08:00
|
|
|
<funcdef>typedef void *<function>(chunk_alloc_t)</function></funcdef>
|
Attempt to expand huge allocations in-place.
This adds support for expanding huge allocations in-place by requesting
memory at a specific address from the chunk allocator.
It's currently only implemented for the chunk recycling path, although
in theory it could also be done by optimistically allocating new chunks.
On Linux, it could attempt an in-place mremap. However, that won't work
in practice since the heap is grown downwards and memory is not unmapped
(in a normal build, at least).
Repeated vector reallocation micro-benchmark:
#include <string.h>
#include <stdlib.h>
int main(void) {
for (size_t i = 0; i < 100; i++) {
void *ptr = NULL;
size_t old_size = 0;
for (size_t size = 4; size < (1 << 30); size *= 2) {
ptr = realloc(ptr, size);
if (!ptr) return 1;
memset(ptr + old_size, 0xff, size - old_size);
old_size = size;
}
free(ptr);
}
}
The glibc allocator fails to do any in-place reallocations on this
benchmark once it passes the M_MMAP_THRESHOLD (default 128k) but it
elides the cost of copies via mremap, which is currently not something
that jemalloc can use.
With this improvement, jemalloc still fails to do any in-place huge
reallocations for the first outer loop, but then succeeds 100% of the
time for the remaining 99 iterations. The time spent doing allocations
and copies drops down to under 5%, with nearly all of it spent doing
purging + faulting (when huge pages are disabled) and the array memset.
An improved mremap API (MREMAP_RETAIN - #138) would be far more general
but this is a portable optimization and would still be useful on Linux
for xallocx.
Numbers with transparent huge pages enabled:
glibc (copies elided via MREMAP_MAYMOVE): 8.471s
jemalloc: 17.816s
jemalloc + no-op madvise: 13.236s
jemalloc + this commit: 6.787s
jemalloc + this commit + no-op madvise: 6.144s
Numbers with transparent huge pages disabled:
glibc (copies elided via MREMAP_MAYMOVE): 15.403s
jemalloc: 39.456s
jemalloc + no-op madvise: 12.768s
jemalloc + this commit: 15.534s
jemalloc + this commit + no-op madvise: 6.354s
Closes #137
2014-10-04 13:39:32 +08:00
|
|
|
<paramdef>void *<parameter>chunk</parameter></paramdef>
|
2014-05-06 06:16:56 +08:00
|
|
|
<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>
|
2014-10-06 05:48:44 +08:00
|
|
|
</funcprototype></funcsynopsis>
|
2014-05-06 06:16:56 +08:00
|
|
|
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
|
Attempt to expand huge allocations in-place.
This adds support for expanding huge allocations in-place by requesting
memory at a specific address from the chunk allocator.
It's currently only implemented for the chunk recycling path, although
in theory it could also be done by optimistically allocating new chunks.
On Linux, it could attempt an in-place mremap. However, that won't work
in practice since the heap is grown downwards and memory is not unmapped
(in a normal build, at least).
Repeated vector reallocation micro-benchmark:
#include <string.h>
#include <stdlib.h>
int main(void) {
for (size_t i = 0; i < 100; i++) {
void *ptr = NULL;
size_t old_size = 0;
for (size_t size = 4; size < (1 << 30); size *= 2) {
ptr = realloc(ptr, size);
if (!ptr) return 1;
memset(ptr + old_size, 0xff, size - old_size);
old_size = size;
}
free(ptr);
}
}
The glibc allocator fails to do any in-place reallocations on this
benchmark once it passes the M_MMAP_THRESHOLD (default 128k) but it
elides the cost of copies via mremap, which is currently not something
that jemalloc can use.
With this improvement, jemalloc still fails to do any in-place huge
reallocations for the first outer loop, but then succeeds 100% of the
time for the remaining 99 iterations. The time spent doing allocations
and copies drops down to under 5%, with nearly all of it spent doing
purging + faulting (when huge pages are disabled) and the array memset.
An improved mremap API (MREMAP_RETAIN - #138) would be far more general
but this is a portable optimization and would still be useful on Linux
for xallocx.
Numbers with transparent huge pages enabled:
glibc (copies elided via MREMAP_MAYMOVE): 8.471s
jemalloc: 17.816s
jemalloc + no-op madvise: 13.236s
jemalloc + this commit: 6.787s
jemalloc + this commit + no-op madvise: 6.144s
Numbers with transparent huge pages disabled:
glibc (copies elided via MREMAP_MAYMOVE): 15.403s
jemalloc: 39.456s
jemalloc + no-op madvise: 12.768s
jemalloc + this commit: 15.534s
jemalloc + this commit + no-op madvise: 6.354s
Closes #137
2014-10-04 13:39:32 +08:00
|
|
|
<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>
|
2014-05-16 13:22:27 +08:00
|
|
|
|
|
|
|
<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>
|
2014-05-06 06:16:56 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2014-05-16 13:22:27 +08:00
|
|
|
<varlistentry id="arena.i.chunk.dalloc">
|
2014-05-06 06:16:56 +08:00
|
|
|
<term>
|
2014-05-16 13:22:27 +08:00
|
|
|
<mallctl>arena.<i>.chunk.dalloc</mallctl>
|
|
|
|
(<type>chunk_dalloc_t *</type>)
|
2014-05-06 06:16:56 +08:00
|
|
|
<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 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.
|
2014-10-06 05:48:44 +08:00
|
|
|
<funcsynopsis><funcprototype>
|
2014-05-16 13:22:27 +08:00
|
|
|
<funcdef>typedef void <function>(chunk_dalloc_t)</function></funcdef>
|
2014-05-06 06:16:56 +08:00
|
|
|
<paramdef>void *<parameter>chunk</parameter></paramdef>
|
|
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
|
|
<paramdef>unsigned <parameter>arena_ind</parameter></paramdef>
|
2014-10-06 05:48:44 +08:00
|
|
|
</funcprototype></funcsynopsis>
|
2014-05-06 06:16:56 +08:00
|
|
|
A chunk deallocation function conforms to the
|
2014-05-16 13:22:27 +08:00
|
|
|
<type>chunk_dalloc_t</type> type and deallocates a
|
2014-05-06 06:16:56 +08:00
|
|
|
<parameter>chunk</parameter> of given <parameter>size</parameter> on
|
|
|
|
behalf of arena <parameter>arena_ind</parameter>.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<varlistentry id="arenas.narenas">
|
|
|
|
<term>
|
|
|
|
<mallctl>arenas.narenas</mallctl>
|
|
|
|
(<type>unsigned</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
</term>
|
2012-10-12 04:53:15 +08:00
|
|
|
<listitem><para>Current limit on number of arenas.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.quantum">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>arenas.quantum</mallctl>
|
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
</term>
|
|
|
|
<listitem><para>Quantum size.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.page">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
2012-04-02 22:04:34 +08:00
|
|
|
<mallctl>arenas.page</mallctl>
|
2010-11-25 14:00:02 +08:00
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
</term>
|
|
|
|
<listitem><para>Page size.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.tcache_max">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.nbins">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>arenas.nbins</mallctl>
|
|
|
|
(<type>unsigned</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
</term>
|
2012-02-29 08:50:47 +08:00
|
|
|
<listitem><para>Number of bin size classes.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.nhbins">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.bin.i.nregs">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.bin.i.run_size">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.nlruns">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>arenas.nlruns</mallctl>
|
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
</term>
|
|
|
|
<listitem><para>Total number of large size classes.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.lrun.i.size">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="arenas.extend">
|
2012-10-12 04:53:15 +08:00
|
|
|
<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>
|
|
|
|
|
2014-10-04 14:25:30 +08:00
|
|
|
<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>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
2014-10-04 14:25:30 +08:00
|
|
|
option for additional information, as well as the interrelated <link
|
|
|
|
linkend="thread.prof.active"><mallctl>thread.prof.active</mallctl></link>
|
|
|
|
mallctl.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="prof.dump">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2014-08-19 07:22:13 +08:00
|
|
|
<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
|
2014-10-03 14:01:10 +08:00
|
|
|
linkend="opt.lg_prof_sample"><mallctl>opt.lg_prof_sample</mallctl></link>
|
2014-10-04 14:25:30 +08:00
|
|
|
and <link
|
|
|
|
linkend="prof.lg_sample"><mallctl>prof.lg_sample</mallctl></link>).
|
2014-08-19 07:22:13 +08:00
|
|
|
</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>
|
2014-10-03 14:01:10 +08:00
|
|
|
<listitem><para>Get the current sample rate (see <link
|
2014-08-19 07:22:13 +08:00
|
|
|
linkend="opt.lg_prof_sample"><mallctl>opt.lg_prof_sample</mallctl></link>).
|
|
|
|
</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="prof.interval">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
2011-03-19 08:56:14 +08:00
|
|
|
</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 to the nearest
|
|
|
|
multiple of the chunk size 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>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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>.
|
2012-10-18 04:06:32 +08:00
|
|
|
This does not include <link linkend="stats.arenas.i.pdirty">
|
|
|
|
<mallctl>stats.arenas.<i>.pdirty</mallctl></link> and pages
|
|
|
|
entirely devoted to allocator metadata.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.mapped">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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
|
2012-05-10 14:08:48 +08:00
|
|
|
does not include inactive chunks.</para></listitem>
|
2010-11-25 14:00:02 +08:00
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.chunks.current">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>stats.chunks.current</mallctl>
|
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-stats</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Total number of chunks actively mapped on behalf of the
|
2012-05-10 14:08:48 +08:00
|
|
|
application. This does not include inactive chunks.
|
2010-11-25 14:00:02 +08:00
|
|
|
</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.chunks.total">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>stats.chunks.total</mallctl>
|
|
|
|
(<type>uint64_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-stats</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Cumulative number of chunks allocated.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.chunks.high">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>stats.chunks.high</mallctl>
|
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-stats</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Maximum number of active chunks at any time thus far.
|
|
|
|
</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.dss">
|
2012-10-12 04:53:15 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.nthreads">
|
2011-03-19 04:41:33 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.pactive">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2012-10-18 04:06:32 +08:00
|
|
|
<varlistentry id="stats.arenas.i.pdirty">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.mapped">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.npurge">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.nmadvise">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-12-20 13:40:41 +08:00
|
|
|
<varlistentry id="stats.arenas.i.purged">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
2013-12-20 13:40:41 +08:00
|
|
|
<mallctl>stats.arenas.<i>.purged</mallctl>
|
2010-11-25 14:00:02 +08:00
|
|
|
(<type>uint64_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-stats</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Number of pages purged.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.small.allocated">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.small.nmalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.small.ndalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.small.nrequests">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.large.allocated">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.large.nmalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.large.ndalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.large.nrequests">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2014-05-16 13:22:27 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.allocated">
|
2010-11-25 14:00:02 +08:00
|
|
|
<term>
|
|
|
|
<mallctl>stats.arenas.<i>.bins.<j>.allocated</mallctl>
|
|
|
|
(<type>size_t</type>)
|
|
|
|
<literal>r-</literal>
|
|
|
|
[<option>--enable-stats</option>]
|
|
|
|
</term>
|
|
|
|
<listitem><para>Current number of bytes allocated by
|
|
|
|
bin.</para></listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nmalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.ndalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nrequests">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nfills">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nflushes">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nruns">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.nreruns">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.bins.j.curruns">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.nmalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.ndalloc">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.nrequests">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
|
2013-10-31 05:52:09 +08:00
|
|
|
<varlistentry id="stats.arenas.i.lruns.j.curruns">
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
|
|
|
</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
|
2012-04-06 15:35:09 +08:00
|
|
|
would be prohibitive. However, jemalloc does integrate with the most
|
2012-04-26 14:17:57 +08:00
|
|
|
excellent <ulink url="http://valgrind.org/">Valgrind</ulink> tool if the
|
2012-05-16 05:48:14 +08:00
|
|
|
<option>--enable-valgrind</option> configuration option is enabled.</para>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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>
|
|
|
|
|
2012-03-14 03:55:21 +08:00
|
|
|
<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>
|
|
|
|
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
<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>
|
2010-11-25 14:00:02 +08:00
|
|
|
|
|
|
|
<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>
|
Implement the *allocx() API.
Implement the *allocx() API, which is a successor to the *allocm() API.
The *allocx() functions are slightly simpler to use because they have
fewer parameters, they directly return the results of primary interest,
and mallocx()/rallocx() avoid the strict aliasing pitfall that
allocm()/rallocx() share with posix_memalign(). The following code
violates strict aliasing rules:
foo_t *foo;
allocm((void **)&foo, NULL, 42, 0);
whereas the following is safe:
foo_t *foo;
void *p;
allocm(&p, NULL, 42, 0);
foo = (foo_t *)p;
mallocx() does not have this problem:
foo_t *foo = (foo_t *)mallocx(42, 0);
2013-12-13 14:35:52 +08:00
|
|
|
|
|
|
|
<para>The <function>malloc_usable_size<parameter/></function> function
|
|
|
|
returns the usable size of the allocation pointed to by
|
|
|
|
<parameter>ptr</parameter>. </para>
|
2010-11-25 14:00:02 +08:00
|
|
|
</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>,
|
2012-04-06 04:36:17 +08:00
|
|
|
<citerefentry><refentrytitle>utrace</refentrytitle>
|
|
|
|
<manvolnum>2</manvolnum></citerefentry>,
|
2010-11-25 14:00:02 +08:00
|
|
|
<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>
|