mirror of
https://codeberg.org/redict/redict.git
synced 2025-01-23 00:28:26 -05:00
1527 lines
96 KiB
HTML
1527 lines
96 KiB
HTML
|
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>JEMALLOC</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" title="JEMALLOC"><a name="id2783946"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>jemalloc — general purpose memory allocation functions</p></div><div class="refsect1" title="LIBRARY"><a name="library"></a><h2>LIBRARY</h2><p>This manual describes jemalloc 2.2.1-0-g5ef7abf6d846720fb3fb8c737861c99b5ad1d862. More information
|
|||
|
|
can be found at the <a class="ulink" href="http://www.canonware.com/jemalloc/" target="_top">jemalloc website</a>.</p></div><div class="refsynopsisdiv" title="SYNOPSIS"><h2>SYNOPSIS</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include <<code class="filename">stdlib.h</code>>
|
|||
|
|
#include <<code class="filename">jemalloc/jemalloc.h</code>></pre><div class="refsect2" title="Standard API"><a name="id2830421"></a><h3>Standard API</h3><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void *<b class="fsfunc">malloc</b>(</code></td><td>size_t <var class="pdparam">size</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void *<b class="fsfunc">calloc</b>(</code></td><td>size_t <var class="pdparam">number</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">size</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">posix_memalign</b>(</code></td><td>void **<var class="pdparam">ptr</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">alignment</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">size</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void *<b class="fsfunc">realloc</b>(</code></td><td>void *<var class="pdparam">ptr</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">size</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void <b class="fsfunc">free</b>(</code></td><td>void *<var class="pdparam">ptr</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div></div><div class="refsect2" title="Non-standard API"><a name="id2837717"></a><h3>Non-standard API</h3><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">size_t <b class="fsfunc">malloc_usable_size</b>(</code></td><td>const void *<var class="pdparam">ptr</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void <b class="fsfunc">malloc_stats_print</b>(</code></td><td>void <var class="pdparam">(*write_cb)</var>
|
|||
|
|
<code>(</code>void *, const char *<code>)</code>
|
|||
|
|
, </td></tr><tr><td><EFBFBD></td><td>void *<var class="pdparam">cbopaque</var>, </td></tr><tr><td><EFBFBD></td><td>const char *<var class="pdparam">opts</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">mallctl</b>(</code></td><td>const char *<var class="pdparam">name</var>, </td></tr><tr><td><EFBFBD></td><td>void *<var class="pdparam">oldp</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">oldlenp</var>, </td></tr><tr><td><EFBFBD></td><td>void *<var class="pdparam">newp</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">newlen</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">mallctlnametomib</b>(</code></td><td>const char *<var class="pdparam">name</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">mibp</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">miblenp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">mallctlbymib</b>(</code></td><td>const size_t *<var class="pdparam">mib</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">miblen</var>, </td></tr><tr><td><EFBFBD></td><td>void *<var class="pdparam">oldp</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">oldlenp</var>, </td></tr><tr><td><EFBFBD></td><td>void *<var class="pdparam">newp</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">newlen</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void <b class="fsfunc">(*malloc_message)</b>(</code></td><td>void *<var class="pdparam">cbopaque</var>, </td></tr><tr><td><EFBFBD></td><td>const char *<var class="pdparam">s</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><p><span class="type">const char *</span><code class="varname">malloc_conf</code>;</p></div><div class="refsect2" title="Experimental API"><a name="id2830042"></a><h3>Experimental API</h3><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">allocm</b>(</code></td><td>void **<var class="pdparam">ptr</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">rsize</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">size</var>, </td></tr><tr><td><EFBFBD></td><td>int <var class="pdparam">flags</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">rallocm</b>(</code></td><td>void **<var class="pdparam">ptr</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">rsize</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">size</var>, </td></tr><tr><td><EFBFBD></td><td>size_t <var class="pdparam">extra</var>, </td></tr><tr><td><EFBFBD></td><td>int <var class="pdparam">flags</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">sallocm</b>(</code></td><td>const void *<var class="pdparam">ptr</var>, </td></tr><tr><td><EFBFBD></td><td>size_t *<var class="pdparam">rsize</var>, </td></tr><tr><td><EFBFBD></td><td>int <var class="pdparam">flags</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"><EFBFBD></div><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-tab
|
|||
|
|
<em class="parameter"><code>size</code></em> bytes of uninitialized memory. The allocated
|
|||
|
|
space is suitably aligned (after possible pointer coercion) for storage
|
|||
|
|
of any type of object.</p><p>The <code class="function">calloc</code>(<em class="parameter"><code></code></em>) function allocates
|
|||
|
|
space for <em class="parameter"><code>number</code></em> objects, each
|
|||
|
|
<em class="parameter"><code>size</code></em> bytes in length. The result is identical to
|
|||
|
|
calling <code class="function">malloc</code>(<em class="parameter"><code></code></em>) with an argument of
|
|||
|
|
<em class="parameter"><code>number</code></em> * <em class="parameter"><code>size</code></em>, with the
|
|||
|
|
exception that the allocated memory is explicitly initialized to zero
|
|||
|
|
bytes.</p><p>The <code class="function">posix_memalign</code>(<em class="parameter"><code></code></em>) function
|
|||
|
|
allocates <em class="parameter"><code>size</code></em> bytes of memory such that the
|
|||
|
|
allocation's base address is an even multiple of
|
|||
|
|
<em class="parameter"><code>alignment</code></em>, and returns the allocation in the value
|
|||
|
|
pointed to by <em class="parameter"><code>ptr</code></em>. The requested
|
|||
|
|
<em class="parameter"><code>alignment</code></em> must be a power of 2 at least as large
|
|||
|
|
as <code class="code">sizeof(<span class="type">void *</span>)</code>.</p><p>The <code class="function">realloc</code>(<em class="parameter"><code></code></em>) function changes the
|
|||
|
|
size of the previously allocated memory referenced by
|
|||
|
|
<em class="parameter"><code>ptr</code></em> to <em class="parameter"><code>size</code></em> 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 <em class="parameter"><code>ptr</code></em> is freed and a pointer to the newly
|
|||
|
|
allocated memory is returned. Note that
|
|||
|
|
<code class="function">realloc</code>(<em class="parameter"><code></code></em>) may move the memory allocation,
|
|||
|
|
resulting in a different return value than <em class="parameter"><code>ptr</code></em>.
|
|||
|
|
If <em class="parameter"><code>ptr</code></em> is <code class="constant">NULL</code>, the
|
|||
|
|
<code class="function">realloc</code>(<em class="parameter"><code></code></em>) function behaves identically to
|
|||
|
|
<code class="function">malloc</code>(<em class="parameter"><code></code></em>) for the specified size.</p><p>The <code class="function">free</code>(<em class="parameter"><code></code></em>) function causes the
|
|||
|
|
allocated memory referenced by <em class="parameter"><code>ptr</code></em> to be made
|
|||
|
|
available for future allocations. If <em class="parameter"><code>ptr</code></em> is
|
|||
|
|
<code class="constant">NULL</code>, no action occurs.</p></div><div class="refsect2" title="Non-standard API"><a name="id2827225"></a><h3>Non-standard API</h3><p>The <code class="function">malloc_usable_size</code>(<em class="parameter"><code></code></em>) function
|
|||
|
|
returns the usable size of the allocation pointed to by
|
|||
|
|
<em class="parameter"><code>ptr</code></em>. The return value may be larger than the size
|
|||
|
|
that was requested during allocation. The
|
|||
|
|
<code class="function">malloc_usable_size</code>(<em class="parameter"><code></code></em>) function is not a
|
|||
|
|
mechanism for in-place <code class="function">realloc</code>(<em class="parameter"><code></code></em>); rather
|
|||
|
|
it is provided solely as a tool for introspection purposes. Any
|
|||
|
|
discrepancy between the requested allocation size and the size reported
|
|||
|
|
by <code class="function">malloc_usable_size</code>(<em class="parameter"><code></code></em>) should not be
|
|||
|
|
depended on, since such behavior is entirely implementation-dependent.
|
|||
|
|
</p><p>The <code class="function">malloc_stats_print</code>(<em class="parameter"><code></code></em>) function
|
|||
|
|
writes human-readable summary statistics via the
|
|||
|
|
<em class="parameter"><code>write_cb</code></em> callback function pointer and
|
|||
|
|
<em class="parameter"><code>cbopaque</code></em> data passed to
|
|||
|
|
<em class="parameter"><code>write_cb</code></em>, or
|
|||
|
|
<code class="function">malloc_message</code>(<em class="parameter"><code></code></em>) if
|
|||
|
|
<em class="parameter"><code>write_cb</code></em> is <code class="constant">NULL</code>. This
|
|||
|
|
function can be called repeatedly. General information that never
|
|||
|
|
changes during execution can be omitted by specifying "g" as a character
|
|||
|
|
within the <em class="parameter"><code>opts</code></em> string. Note that
|
|||
|
|
<code class="function">malloc_message</code>(<em class="parameter"><code></code></em>) uses the
|
|||
|
|
<code class="function">mallctl*</code>(<em class="parameter"><code></code></em>) functions internally, so
|
|||
|
|
inconsistent statistics can be reported if multiple threads use these
|
|||
|
|
functions simultaneously. If <code class="option">--enable-stats</code> 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.
|
|||
|
|
</p><p>The <code class="function">mallctl</code>(<em class="parameter"><code></code></em>) function provides a
|
|||
|
|
general interface for introspecting the memory allocator, as well as
|
|||
|
|
setting modifiable parameters and triggering actions. The
|
|||
|
|
period-separated <em class="parameter"><code>name</code></em> argument specifies a
|
|||
|
|
location in a tree-structured namespace; see the <a class="xref" href="#mallctl_namespace" title="MALLCTL NAMESPACE">MALLCTL NAMESPACE</a> section for
|
|||
|
|
documentation on the tree contents. To read a value, pass a pointer via
|
|||
|
|
<em class="parameter"><code>oldp</code></em> to adequate space to contain the value, and a
|
|||
|
|
pointer to its length via <em class="parameter"><code>oldlenp</code></em>; otherwise pass
|
|||
|
|
<code class="constant">NULL</code> and <code class="constant">NULL</code>. Similarly, to
|
|||
|
|
write a value, pass a pointer to the value via
|
|||
|
|
<em class="parameter"><code>newp</code></em>, and its length via
|
|||
|
|
<em class="parameter"><code>newlen</code></em>; otherwise pass <code class="constant">NULL</code>
|
|||
|
|
and <code class="constant">0</code>.</p><p>The <code class="function">mallctlnametomib</code>(<em class="parameter"><code></code></em>) 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 <code class="function">mallctlbymib</code>(<em class="parameter"><code></code></em>). Upon
|
|||
|
|
successful return from <code class="function">mallctlnametomib</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<em class="parameter"><code>mibp</code></em> contains an array of
|
|||
|
|
<em class="parameter"><code>*miblenp</code></em> integers, where
|
|||
|
|
<em class="parameter"><code>*miblenp</code></em> is the lesser of the number of components
|
|||
|
|
in <em class="parameter"><code>name</code></em> and the input value of
|
|||
|
|
<em class="parameter"><code>*miblenp</code></em>. Thus it is possible to pass a
|
|||
|
|
<em class="parameter"><code>*miblenp</code></em> 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
|
|||
|
|
<a class="link" href="#arenas.bin.i.size">
|
|||
|
|
"<code class="mallctl">arenas.bin.2.size</code>"
|
|||
|
|
</a>),
|
|||
|
|
the corresponding MIB component will always be that integer. Therefore,
|
|||
|
|
it is legitimate to construct code like the following: </p><pre class="programlisting">
|
|||
|
|
unsigned nbins, i;
|
|||
|
|
|
|||
|
|
int mib[4];
|
|||
|
|
size_t len, miblen;
|
|||
|
|
|
|||
|
|
len = sizeof(nbins);
|
|||
|
|
mallctl("arenas.nbins", &nbins, &len, NULL, 0);
|
|||
|
|
|
|||
|
|
miblen = 4;
|
|||
|
|
mallnametomib("arenas.bin.0.size", mib, &miblen);
|
|||
|
|
for (i = 0; i < nbins; i++) {
|
|||
|
|
size_t bin_size;
|
|||
|
|
|
|||
|
|
mib[2] = i;
|
|||
|
|
len = sizeof(bin_size);
|
|||
|
|
mallctlbymib(mib, miblen, &bin_size, &len, NULL, 0);
|
|||
|
|
/* Do something with bin_size... */
|
|||
|
|
}</pre></div><div class="refsect2" title="Experimental API"><a name="id2807945"></a><h3>Experimental API</h3><p>The experimental API is subject to change or removal without regard
|
|||
|
|
for backward compatibility.</p><p>The <code class="function">allocm</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">rallocm</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">sallocm</code>(<em class="parameter"><code></code></em>), and
|
|||
|
|
<code class="function">dallocm</code>(<em class="parameter"><code></code></em>) functions all have a
|
|||
|
|
<em class="parameter"><code>flags</code></em> argument that can be used to specify
|
|||
|
|
options. The functions only check the options that are contextually
|
|||
|
|
relevant. Use bitwise or (<code class="code">|</code>) operations to
|
|||
|
|
specify one or more of the following:
|
|||
|
|
</p><div class="variablelist"><dl><dt><span class="term"><code class="constant">ALLOCM_LG_ALIGN(<em class="parameter"><code>la</code></em>)
|
|||
|
|
</code></span></dt><dd><p>Align the memory allocation to start at an address
|
|||
|
|
that is a multiple of <code class="code">(1 <<
|
|||
|
|
<em class="parameter"><code>la</code></em>)</code>. This macro does not validate
|
|||
|
|
that <em class="parameter"><code>la</code></em> is within the valid
|
|||
|
|
range.</p></dd><dt><span class="term"><code class="constant">ALLOCM_ALIGN(<em class="parameter"><code>a</code></em>)
|
|||
|
|
</code></span></dt><dd><p>Align the memory allocation to start at an address
|
|||
|
|
that is a multiple of <em class="parameter"><code>a</code></em>, where
|
|||
|
|
<em class="parameter"><code>a</code></em> is a power of two. This macro does not
|
|||
|
|
validate that <em class="parameter"><code>a</code></em> is a power of 2.
|
|||
|
|
</p></dd><dt><span class="term"><code class="constant">ALLOCM_ZERO</code></span></dt><dd><p>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 option is
|
|||
|
|
absent, newly allocated memory is uninitialized.</p></dd><dt><span class="term"><code class="constant">ALLOCM_NO_MOVE</code></span></dt><dd><p>For reallocation, fail rather than moving the
|
|||
|
|
object. This constraint can apply to both growth and
|
|||
|
|
shrinkage.</p></dd></dl></div><p>
|
|||
|
|
</p><p>The <code class="function">allocm</code>(<em class="parameter"><code></code></em>) function allocates at
|
|||
|
|
least <em class="parameter"><code>size</code></em> bytes of memory, sets
|
|||
|
|
<em class="parameter"><code>*ptr</code></em> to the base address of the allocation, and
|
|||
|
|
sets <em class="parameter"><code>*rsize</code></em> to the real size of the allocation if
|
|||
|
|
<em class="parameter"><code>rsize</code></em> is not <code class="constant">NULL</code>.</p><p>The <code class="function">rallocm</code>(<em class="parameter"><code></code></em>) function resizes the
|
|||
|
|
allocation at <em class="parameter"><code>*ptr</code></em> to be at least
|
|||
|
|
<em class="parameter"><code>size</code></em> bytes, sets <em class="parameter"><code>*ptr</code></em> to
|
|||
|
|
the base address of the allocation if it moved, and sets
|
|||
|
|
<em class="parameter"><code>*rsize</code></em> to the real size of the allocation if
|
|||
|
|
<em class="parameter"><code>rsize</code></em> is not <code class="constant">NULL</code>. If
|
|||
|
|
<em class="parameter"><code>extra</code></em> is non-zero, an attempt is made to resize
|
|||
|
|
the allocation to be at least <code class="code"><em class="parameter"><code>size</code></em> +
|
|||
|
|
<em class="parameter"><code>extra</code></em>)</code> bytes, though inability to allocate
|
|||
|
|
the extra byte(s) will not by itself result in failure. Behavior is
|
|||
|
|
undefined if <code class="code">(<em class="parameter"><code>size</code></em> +
|
|||
|
|
<em class="parameter"><code>extra</code></em> >
|
|||
|
|
<code class="constant">SIZE_T_MAX</code>)</code>.</p><p>The <code class="function">sallocm</code>(<em class="parameter"><code></code></em>) function sets
|
|||
|
|
<em class="parameter"><code>*rsize</code></em> to the real size of the allocation.</p><p>The <code class="function">dallocm</code>(<em class="parameter"><code></code></em>) function causes the
|
|||
|
|
memory referenced by <em class="parameter"><code>ptr</code></em> to be made available for
|
|||
|
|
future allocations.</p></div></div><div class="refsect1" title="TUNING"><a name="tuning"></a><h2>TUNING</h2><p>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.</p><p>The string pointed to by the global variable
|
|||
|
|
<code class="varname">malloc_conf</code>, the “name” of the file
|
|||
|
|
referenced by the symbolic link named <code class="filename">/etc/malloc.conf</code>, and the value of the
|
|||
|
|
environment variable <code class="envar">MALLOC_CONF</code>, will be interpreted, in
|
|||
|
|
that order, from left to right as options.</p><p>An options string is a comma-separated list of option:value pairs.
|
|||
|
|
There is one key corresponding to each <a class="link" href="#opt.abort">
|
|||
|
|
"<code class="mallctl">opt.*</code>"
|
|||
|
|
</a> mallctl (see the <a class="xref" href="#mallctl_namespace" title="MALLCTL NAMESPACE">MALLCTL NAMESPACE</a> section for options
|
|||
|
|
documentation). For example, <code class="literal">abort:true,narenas:1</code> sets
|
|||
|
|
the <a class="link" href="#opt.abort">
|
|||
|
|
"<code class="mallctl">opt.abort</code>"
|
|||
|
|
</a> and <a class="link" href="#opt.narenas">
|
|||
|
|
"<code class="mallctl">opt.narenas</code>"
|
|||
|
|
</a> 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.</p></div><div class="refsect1" title="IMPLEMENTATION NOTES"><a name="implementation_notes"></a><h2>IMPLEMENTATION NOTES</h2><p>Traditionally, allocators have used
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">sbrk</span>(2)</span> to obtain memory, which is
|
|||
|
|
suboptimal for several reasons, including race conditions, increased
|
|||
|
|
fragmentation, and artificial limitations on maximum usable memory. If
|
|||
|
|
<code class="option">--enable-dss</code> is specified during configuration, this
|
|||
|
|
allocator uses both <span class="citerefentry"><span class="refentrytitle">sbrk</span>(2)</span> and
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">mmap</span>(2)</span>, in that order of preference;
|
|||
|
|
otherwise only <span class="citerefentry"><span class="refentrytitle">mmap</span>(2)</span> is used.</p><p>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.</p><p>In addition to multiple arenas, unless
|
|||
|
|
<code class="option">--disable-tcache</code> 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.</p><p>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.</p><p>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
|
|||
|
|
the chunk size. Small and large objects are managed by arenas; huge
|
|||
|
|
objects are managed separately in a single data structure that is shared by
|
|||
|
|
all threads. Huge objects are used by applications infrequently enough
|
|||
|
|
that this single data structure is not a scalability issue.</p><p>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.</p><p>Small objects are managed in groups by page runs. Each run maintains
|
|||
|
|
a frontier and free list to track which regions are in use. Unless
|
|||
|
|
<code class="option">--disable-tiny</code> is specified during configuration,
|
|||
|
|
allocation requests that are no more than half the quantum (8 or 16,
|
|||
|
|
depending on architecture) are rounded up to the nearest power of two that
|
|||
|
|
is at least <code class="code">sizeof(<span class="type">void *</span>)</code>.
|
|||
|
|
Allocation requests that are more than half the quantum, but no more than
|
|||
|
|
the minimum cacheline-multiple size class (see the <a class="link" href="#opt.lg_qspace_max">
|
|||
|
|
"<code class="mallctl">opt.lg_qspace_max</code>"
|
|||
|
|
</a>
|
|||
|
|
option) are rounded up to the nearest multiple of the quantum. Allocation
|
|||
|
|
requests that are more than the minimum cacheline-multiple size class, but
|
|||
|
|
no more than the minimum subpage-multiple size class (see the <a class="link" href="#opt.lg_cspace_max">
|
|||
|
|
"<code class="mallctl">opt.lg_cspace_max</code>"
|
|||
|
|
</a>
|
|||
|
|
option) are rounded up to the nearest multiple of the cacheline size (64).
|
|||
|
|
Allocation requests that are more than the minimum subpage-multiple size
|
|||
|
|
class, but no more than the maximum subpage-multiple size class are rounded
|
|||
|
|
up to the nearest multiple of the subpage size (256). Allocation requests
|
|||
|
|
that are more than the maximum subpage-multiple size class, but small
|
|||
|
|
enough to fit in an arena-managed chunk (see the <a class="link" href="#opt.lg_chunk">
|
|||
|
|
"<code class="mallctl">opt.lg_chunk</code>"
|
|||
|
|
</a> 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.</p><p>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.</p><p>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 <a class="xref" href="#size_classes" title="Table<6C>1.<2E>Size classes">Table 1</a>.</p><div class="table"><a name="size_classes"></a><p class="title"><b>Table<EFBFBD>1.<2E>Size classes</b></p><div class="table-contents"><table summary="Size classes" border="1"><colgroup><col align="left"><col align="left"><col align="left"></colgroup><thead><tr><th align="left">Category</th><th align="left">Subcategory</th><th align="left">Size</th></tr></thead><tbody><tr><td rowspan="4" align="left">Small</td><td align="left">Tiny</td><td align="left">[8]</td></tr><tr><td align="left">Quantum-spaced</td><td align="left">[16, 32, 48, ..., 128]</td></tr><tr><td align="left">Cacheline-spaced</td><td align="left">[192, 256, 320, ..., 512]</td></tr><tr><td align="left">Subpage-spaced</td><td align="left">[768, 1024, 1280, ..., 3840]</td></tr><tr><td colspan="2" align="left">Large</td><td align="left">[4 KiB, 8 KiB, 12 KiB, ..., 4072 KiB]</td></tr><tr><td colspan="2" align="left">Huge</td><td align="left">[4 MiB, 8 MiB, 12 MiB, ...]</td></tr></tbody></table></div></div><br class="table-break"></div><div class="refsect1" title="MALLCTL NAMESPACE"><a name="mallctl_namespace"></a><h2>MALLCTL NAMESPACE</h2><p>The following names are defined in the namespace accessible via the
|
|||
|
|
<code class="function">mallctl*</code>(<em class="parameter"><code></code></em>) functions. Value types are
|
|||
|
|
specified in parentheses, their readable/writable statuses are encoded as
|
|||
|
|
<code class="literal">rw</code>, <code class="literal">r-</code>, <code class="literal">-w</code>, or
|
|||
|
|
<code class="literal">--</code>, and required build configuration flags follow, if
|
|||
|
|
any. A name element encoded as <code class="literal"><i></code> or
|
|||
|
|
<code class="literal"><j></code> indicates an integer component, where the
|
|||
|
|
integer varies from 0 to some upper value that must be determined via
|
|||
|
|
introspection. In the case of
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.*</code>"
|
|||
|
|
,
|
|||
|
|
<code class="literal"><i></code> equal to <a class="link" href="#arenas.narenas">
|
|||
|
|
"<code class="mallctl">arenas.narenas</code>"
|
|||
|
|
</a> can be
|
|||
|
|
used to access the summation of statistics from all arenas. Take special
|
|||
|
|
note of the <a class="link" href="#epoch">
|
|||
|
|
"<code class="mallctl">epoch</code>"
|
|||
|
|
</a> mallctl,
|
|||
|
|
which controls refreshing of cached dynamic statistics.</p><div class="variablelist"><dl><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">version</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">const char *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Return the jemalloc version string.</p></dd><dt><a name="epoch"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">epoch</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">rw</code>
|
|||
|
|
</span></dt><dd><p>If a value is passed in, refresh the data from which
|
|||
|
|
the <code class="function">mallctl*</code>(<em class="parameter"><code></code></em>) functions report values,
|
|||
|
|
and increment the epoch. Return the current epoch. This is useful for
|
|||
|
|
detecting whether another thread caused a refresh.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.debug</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-debug</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.dss</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-dss</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.dynamic_page_shift</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-dynamic-page-shift</code> was
|
|||
|
|
specified during build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.fill</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-fill</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.lazy_lock</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-lazy-lock</code> was specified
|
|||
|
|
during build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.prof</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-prof</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.prof_libgcc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--disable-prof-libgcc</code> was not
|
|||
|
|
specified during build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.prof_libunwind</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-prof-libunwind</code> was specified
|
|||
|
|
during build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.stats</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-stats</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.swap</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-swap</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.sysv</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-sysv</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.tcache</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--disable-tcache</code> was not specified
|
|||
|
|
during build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.tiny</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--disable-tiny</code> was not specified
|
|||
|
|
during build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.tls</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--disable-tls</code> was not specified during
|
|||
|
|
build configuration.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">config.xmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p><code class="option">--enable-xmalloc</code> was specified during
|
|||
|
|
build configuration.</p></dd><dt><a name="opt.abort"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.abort</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Abort-on-warning enabled/disabled. If true, most
|
|||
|
|
warnings are fatal. The process will call
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">abort</span>(3)</span> in these cases. This option is
|
|||
|
|
disabled by default unless <code class="option">--enable-debug</code> is
|
|||
|
|
specified during configuration, in which case it is enabled by default.
|
|||
|
|
</p></dd><dt><a name="opt.lg_qspace_max"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_qspace_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Size (log base 2) of the maximum size class that is a
|
|||
|
|
multiple of the quantum (8 or 16 bytes, depending on architecture).
|
|||
|
|
Above this size, cacheline spacing is used for size classes. The
|
|||
|
|
default value is 128 bytes (2^7).</p></dd><dt><a name="opt.lg_cspace_max"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_cspace_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Size (log base 2) of the maximum size class that is a
|
|||
|
|
multiple of the cacheline size (64). Above this size, subpage spacing
|
|||
|
|
(256 bytes) is used for size classes. The default value is 512 bytes
|
|||
|
|
(2^9).</p></dd><dt><a name="opt.lg_chunk"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_chunk</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Virtual memory chunk size (log base 2). The default
|
|||
|
|
chunk size is 4 MiB (2^22).</p></dd><dt><a name="opt.narenas"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.narenas</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum number of arenas to use. The default maximum
|
|||
|
|
number of arenas is four times the number of CPUs, or one if there is a
|
|||
|
|
single CPU.</p></dd><dt><a name="opt.lg_dirty_mult"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_dirty_mult</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">ssize_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>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 <span class="citerefentry"><span class="refentrytitle">madvise</span>(2)</span> or a similar system call. This
|
|||
|
|
provides the kernel with sufficient information to recycle dirty pages
|
|||
|
|
if physical memory becomes scarce and the pages remain unused. The
|
|||
|
|
default minimum ratio is 32:1 (2^5:1); an option value of -1 will
|
|||
|
|
disable dirty page purging.</p></dd><dt><a name="opt.stats_print"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.stats_print</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Enable/disable statistics printing at exit. If
|
|||
|
|
enabled, the <code class="function">malloc_stats_print</code>(<em class="parameter"><code></code></em>)
|
|||
|
|
function is called at program exit via an
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">atexit</span>(3)</span> function. If
|
|||
|
|
<code class="option">--enable-stats</code> 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.</p></dd><dt><a name="opt.junk"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.junk</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-fill</code>]
|
|||
|
|
</span></dt><dd><p>Junk filling enabled/disabled. If enabled, each byte
|
|||
|
|
of uninitialized allocated memory will be initialized to
|
|||
|
|
<code class="literal">0xa5</code>. All deallocated memory will be initialized to
|
|||
|
|
<code class="literal">0x5a</code>. This is intended for debugging and will
|
|||
|
|
impact performance negatively. This option is disabled by default
|
|||
|
|
unless <code class="option">--enable-debug</code> is specified during
|
|||
|
|
configuration, in which case it is enabled by default.</p></dd><dt><a name="opt.zero"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.zero</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-fill</code>]
|
|||
|
|
</span></dt><dd><p>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
|
|||
|
|
<code class="function">realloc</code>(<em class="parameter"><code></code></em>) and
|
|||
|
|
<code class="function">rallocm</code>(<em class="parameter"><code></code></em>) calls do not zero memory that
|
|||
|
|
was previously allocated. This is intended for debugging and will
|
|||
|
|
impact performance negatively. This option is disabled by default.
|
|||
|
|
</p></dd><dt><a name="opt.sysv"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.sysv</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-sysv</code>]
|
|||
|
|
</span></dt><dd><p>If enabled, attempting to allocate zero bytes will
|
|||
|
|
return a <code class="constant">NULL</code> pointer instead of a valid pointer.
|
|||
|
|
(The default behavior is to make a minimal allocation and return a
|
|||
|
|
pointer to it.) This option is provided for System V compatibility.
|
|||
|
|
This option is incompatible with the <a class="link" href="#opt.xmalloc">
|
|||
|
|
"<code class="mallctl">opt.xmalloc</code>"
|
|||
|
|
</a> option.
|
|||
|
|
This option is disabled by default.</p></dd><dt><a name="opt.xmalloc"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.xmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-xmalloc</code>]
|
|||
|
|
</span></dt><dd><p>Abort-on-out-of-memory enabled/disabled. If enabled,
|
|||
|
|
rather than returning failure for any allocation function, display a
|
|||
|
|
diagnostic message on <code class="constant">STDERR_FILENO</code> and cause the
|
|||
|
|
program to drop core (using
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">abort</span>(3)</span>). If an application is
|
|||
|
|
designed to depend on this behavior, set the option at compile time by
|
|||
|
|
including the following in the source code:
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
malloc_conf = "xmalloc:true";</pre><p>
|
|||
|
|
This option is disabled by default.</p></dd><dt><a name="opt.tcache"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.tcache</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>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
|
|||
|
|
<a class="link" href="#opt.lg_tcache_gc_sweep">
|
|||
|
|
"<code class="mallctl">opt.lg_tcache_gc_sweep</code>"
|
|||
|
|
</a>
|
|||
|
|
and <a class="link" href="#opt.lg_tcache_max">
|
|||
|
|
"<code class="mallctl">opt.lg_tcache_max</code>"
|
|||
|
|
</a>
|
|||
|
|
options for related tuning information. This option is enabled by
|
|||
|
|
default.</p></dd><dt><a name="opt.lg_tcache_gc_sweep"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_tcache_gc_sweep</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">ssize_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>Approximate interval (log base 2) between full
|
|||
|
|
thread-specific cache garbage collection sweeps, counted in terms of
|
|||
|
|
thread-specific cache allocation/deallocation events. Garbage
|
|||
|
|
collection is actually performed incrementally, one size class at a
|
|||
|
|
time, in order to avoid large collection pauses. The default sweep
|
|||
|
|
interval is 8192 (2^13); setting this option to -1 will disable garbage
|
|||
|
|
collection.</p></dd><dt><a name="opt.lg_tcache_max"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_tcache_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>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).</p></dd><dt><a name="opt.prof"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.prof</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Memory profiling enabled/disabled. If enabled, profile
|
|||
|
|
memory allocation activity, and use an
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">atexit</span>(3)</span> function to dump final memory
|
|||
|
|
usage to a file named according to the pattern
|
|||
|
|
<code class="filename"><prefix>.<pid>.<seq>.f.heap</code>,
|
|||
|
|
where <code class="literal"><prefix></code> is controlled by the <a class="link" href="#opt.prof_prefix">
|
|||
|
|
"<code class="mallctl">opt.prof_prefix</code>"
|
|||
|
|
</a>
|
|||
|
|
option. See the <a class="link" href="#opt.lg_prof_bt_max">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_bt_max</code>"
|
|||
|
|
</a>
|
|||
|
|
option for backtrace depth control. See the <a class="link" href="#opt.prof_active">
|
|||
|
|
"<code class="mallctl">opt.prof_active</code>"
|
|||
|
|
</a>
|
|||
|
|
option for on-the-fly activation/deactivation. See the <a class="link" href="#opt.lg_prof_sample">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_sample</code>"
|
|||
|
|
</a>
|
|||
|
|
option for probabilistic sampling control. See the <a class="link" href="#opt.prof_accum">
|
|||
|
|
"<code class="mallctl">opt.prof_accum</code>"
|
|||
|
|
</a>
|
|||
|
|
option for control of cumulative sample reporting. See the <a class="link" href="#opt.lg_prof_tcmax">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_tcmax</code>"
|
|||
|
|
</a>
|
|||
|
|
option for control of per thread backtrace caching. See the <a class="link" href="#opt.lg_prof_interval">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_interval</code>"
|
|||
|
|
</a>
|
|||
|
|
option for information on interval-triggered profile dumping, and the
|
|||
|
|
<a class="link" href="#opt.prof_gdump">
|
|||
|
|
"<code class="mallctl">opt.prof_gdump</code>"
|
|||
|
|
</a>
|
|||
|
|
option for information on high-water-triggered profile dumping.
|
|||
|
|
Profile output is compatible with the included <span class="command"><strong>pprof</strong></span>
|
|||
|
|
Perl script, which originates from the <a class="ulink" href="http://code.google.com/p/google-perftools/" target="_top">google-perftools
|
|||
|
|
package</a>.</p></dd><dt><a name="opt.prof_prefix"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.prof_prefix</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">const char *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>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
|
|||
|
|
<code class="filename">jeprof</code>.</p></dd><dt><a name="opt.lg_prof_bt_max"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_prof_bt_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Maximum backtrace depth (log base 2) when profiling
|
|||
|
|
memory allocation activity. The default is 128 (2^7).</p></dd><dt><a name="opt.prof_active"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.prof_active</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Profiling activated/deactivated. This is a secondary
|
|||
|
|
control mechanism that makes it possible to start the application with
|
|||
|
|
profiling enabled (see the <a class="link" href="#opt.prof">
|
|||
|
|
"<code class="mallctl">opt.prof</code>"
|
|||
|
|
</a> option) but
|
|||
|
|
inactive, then toggle profiling at any time during program execution
|
|||
|
|
with the <a class="link" href="#prof.active">
|
|||
|
|
"<code class="mallctl">prof.active</code>"
|
|||
|
|
</a> mallctl.
|
|||
|
|
This option is enabled by default.</p></dd><dt><a name="opt.lg_prof_sample"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_prof_sample</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">ssize_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Average interval (log base 2) between allocation
|
|||
|
|
samples, as measured in bytes of allocation activity. Increasing the
|
|||
|
|
sampling interval decreases profile fidelity, but also decreases the
|
|||
|
|
computational overhead. The default sample interval is 1 (2^0) (i.e.
|
|||
|
|
all allocations are sampled).</p></dd><dt><a name="opt.prof_accum"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.prof_accum</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Reporting of cumulative object/byte counts in profile
|
|||
|
|
dumps enabled/disabled. If this option is enabled, every unique
|
|||
|
|
backtrace must be stored for the duration of execution. Depending on
|
|||
|
|
the application, this can impose a large memory overhead, and the
|
|||
|
|
cumulative counts are not always of interest. See the
|
|||
|
|
<a class="link" href="#opt.lg_prof_tcmax">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_tcmax</code>"
|
|||
|
|
</a>
|
|||
|
|
option for control of per thread backtrace caching, which has important
|
|||
|
|
interactions. This option is enabled by default.</p></dd><dt><a name="opt.lg_prof_tcmax"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_prof_tcmax</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">ssize_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Maximum per thread backtrace cache (log base 2) used
|
|||
|
|
for heap profiling. A backtrace can only be discarded if the
|
|||
|
|
<a class="link" href="#opt.prof_accum">
|
|||
|
|
"<code class="mallctl">opt.prof_accum</code>"
|
|||
|
|
</a>
|
|||
|
|
option is disabled, and no thread caches currently refer to the
|
|||
|
|
backtrace. Therefore, a backtrace cache limit should be imposed if the
|
|||
|
|
intention is to limit how much memory is used by backtraces. By
|
|||
|
|
default, no limit is imposed (encoded as -1).
|
|||
|
|
</p></dd><dt><a name="opt.lg_prof_interval"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.lg_prof_interval</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">ssize_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>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
|
|||
|
|
<code class="filename"><prefix>.<pid>.<seq>.i<iseq>.heap</code>,
|
|||
|
|
where <code class="literal"><prefix></code> is controlled by the
|
|||
|
|
<a class="link" href="#opt.prof_prefix">
|
|||
|
|
"<code class="mallctl">opt.prof_prefix</code>"
|
|||
|
|
</a>
|
|||
|
|
option. By default, interval-triggered profile dumping is disabled
|
|||
|
|
(encoded as -1).
|
|||
|
|
</p></dd><dt><a name="opt.prof_gdump"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.prof_gdump</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>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
|
|||
|
|
<code class="filename"><prefix>.<pid>.<seq>.u<useq>.heap</code>,
|
|||
|
|
where <code class="literal"><prefix></code> is controlled by the <a class="link" href="#opt.prof_prefix">
|
|||
|
|
"<code class="mallctl">opt.prof_prefix</code>"
|
|||
|
|
</a>
|
|||
|
|
option. This option is disabled by default.</p></dd><dt><a name="opt.prof_leak"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.prof_leak</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Leak reporting enabled/disabled. If enabled, use an
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">atexit</span>(3)</span> function to report memory leaks
|
|||
|
|
detected by allocation sampling. See the
|
|||
|
|
<a class="link" href="#opt.lg_prof_bt_max">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_bt_max</code>"
|
|||
|
|
</a>
|
|||
|
|
option for backtrace depth control. See the
|
|||
|
|
<a class="link" href="#opt.prof">
|
|||
|
|
"<code class="mallctl">opt.prof</code>"
|
|||
|
|
</a> option for
|
|||
|
|
information on analyzing heap profile output. This option is disabled
|
|||
|
|
by default.</p></dd><dt><a name="opt.overcommit"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">opt.overcommit</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-swap</code>]
|
|||
|
|
</span></dt><dd><p>Over-commit enabled/disabled. If enabled, over-commit
|
|||
|
|
memory as a side effect of using anonymous
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">mmap</span>(2)</span> or
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">sbrk</span>(2)</span> for virtual memory allocation.
|
|||
|
|
In order for overcommit to be disabled, the <a class="link" href="#swap.fds">
|
|||
|
|
"<code class="mallctl">swap.fds</code>"
|
|||
|
|
</a> mallctl must have
|
|||
|
|
been successfully written to. This option is enabled by
|
|||
|
|
default.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">tcache.flush</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">void</span>)
|
|||
|
|
<code class="literal">--</code>
|
|||
|
|
[<code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>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.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">thread.arena</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">rw</code>
|
|||
|
|
</span></dt><dd><p>Get or set the arena associated with the calling
|
|||
|
|
thread. The arena index must be less than the maximum number of arenas
|
|||
|
|
(see the <a class="link" href="#arenas.narenas">
|
|||
|
|
"<code class="mallctl">arenas.narenas</code>"
|
|||
|
|
</a>
|
|||
|
|
mallctl). If the specified arena was not initialized beforehand (see
|
|||
|
|
the <a class="link" href="#arenas.initialized">
|
|||
|
|
"<code class="mallctl">arenas.initialized</code>"
|
|||
|
|
</a>
|
|||
|
|
mallctl), it will be automatically initialized as a side effect of
|
|||
|
|
calling this interface.</p></dd><dt><a name="thread.allocated"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">thread.allocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>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.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">thread.allocatedp</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Get a pointer to the the value that is returned by the
|
|||
|
|
<a class="link" href="#thread.allocated">
|
|||
|
|
"<code class="mallctl">thread.allocated</code>"
|
|||
|
|
</a>
|
|||
|
|
mallctl. This is useful for avoiding the overhead of repeated
|
|||
|
|
<code class="function">mallctl*</code>(<em class="parameter"><code></code></em>) calls.</p></dd><dt><a name="thread.deallocated"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">thread.deallocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>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.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">thread.deallocatedp</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Get a pointer to the the value that is returned by the
|
|||
|
|
<a class="link" href="#thread.deallocated">
|
|||
|
|
"<code class="mallctl">thread.deallocated</code>"
|
|||
|
|
</a>
|
|||
|
|
mallctl. This is useful for avoiding the overhead of repeated
|
|||
|
|
<code class="function">mallctl*</code>(<em class="parameter"><code></code></em>) calls.</p></dd><dt><a name="arenas.narenas"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.narenas</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum number of arenas.</p></dd><dt><a name="arenas.initialized"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.initialized</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>An array of <a class="link" href="#arenas.narenas">
|
|||
|
|
"<code class="mallctl">arenas.narenas</code>"
|
|||
|
|
</a>
|
|||
|
|
booleans. Each boolean indicates whether the corresponding arena is
|
|||
|
|
initialized.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.quantum</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Quantum size.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.cacheline</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Assumed cacheline size.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.subpage</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Subpage size class interval.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.pagesize</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Page size.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.chunksize</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Chunk size.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.tspace_min</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Minimum tiny size class. Tiny size classes are powers
|
|||
|
|
of two.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.tspace_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum tiny size class. Tiny size classes are powers
|
|||
|
|
of two.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.qspace_min</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Minimum quantum-spaced size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.qspace_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum quantum-spaced size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.cspace_min</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Minimum cacheline-spaced size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.cspace_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum cacheline-spaced size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.sspace_min</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Minimum subpage-spaced size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.sspace_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum subpage-spaced size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.tcache_max</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>Maximum thread-cached size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.ntbins</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of tiny bin size classes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.nqbins</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of quantum-spaced bin size
|
|||
|
|
classes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.ncbins</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of cacheline-spaced bin size
|
|||
|
|
classes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.nsbins</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of subpage-spaced bin size
|
|||
|
|
classes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.nbins</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Total number of bin size classes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.nhbins</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>Total number of thread cache bin size
|
|||
|
|
classes.</p></dd><dt><a name="arenas.bin.i.size"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.bin.<i>.size</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum size supported by size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.bin.<i>.nregs</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint32_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of regions per page run.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.bin.<i>.run_size</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of bytes per page run.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.nlruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Total number of large size classes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.lrun.<i>.size</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Maximum size supported by this large size
|
|||
|
|
class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">arenas.purge</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">-w</code>
|
|||
|
|
</span></dt><dd><p>Purge unused dirty pages for the specified arena, or
|
|||
|
|
for all arenas if none is specified.</p></dd><dt><a name="prof.active"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">prof.active</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">rw</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Control whether sampling is currently active. See the
|
|||
|
|
<a class="link" href="#opt.prof_active">
|
|||
|
|
"<code class="mallctl">opt.prof_active</code>"
|
|||
|
|
</a>
|
|||
|
|
option for additional information.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">prof.dump</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">const char *</span>)
|
|||
|
|
<code class="literal">-w</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Dump a memory profile to the specified file, or if NULL
|
|||
|
|
is specified, to a file according to the pattern
|
|||
|
|
<code class="filename"><prefix>.<pid>.<seq>.m<mseq>.heap</code>,
|
|||
|
|
where <code class="literal"><prefix></code> is controlled by the
|
|||
|
|
<a class="link" href="#opt.prof_prefix">
|
|||
|
|
"<code class="mallctl">opt.prof_prefix</code>"
|
|||
|
|
</a>
|
|||
|
|
option.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">prof.interval</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-prof</code>]
|
|||
|
|
</span></dt><dd><p>Average number of bytes allocated between
|
|||
|
|
inverval-based profile dumps. See the
|
|||
|
|
<a class="link" href="#opt.lg_prof_interval">
|
|||
|
|
"<code class="mallctl">opt.lg_prof_interval</code>"
|
|||
|
|
</a>
|
|||
|
|
option for additional information.</p></dd><dt><a name="stats.cactive"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.cactive</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>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 <a class="link" href="#epoch">
|
|||
|
|
"<code class="mallctl">epoch</code>"
|
|||
|
|
</a> 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.
|
|||
|
|
</p></dd><dt><a name="stats.allocated"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.allocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Total number of bytes allocated by the
|
|||
|
|
application.</p></dd><dt><a name="stats.active"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.active</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>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 <a class="link" href="#stats.allocated">
|
|||
|
|
"<code class="mallctl">stats.allocated</code>"
|
|||
|
|
</a>.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.mapped</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>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 <a class="link" href="#stats.active">
|
|||
|
|
"<code class="mallctl">stats.active</code>"
|
|||
|
|
</a>. This
|
|||
|
|
does not include inactive chunks backed by swap files. his does not
|
|||
|
|
include inactive chunks embedded in the DSS.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.chunks.current</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Total number of chunks actively mapped on behalf of the
|
|||
|
|
application. This does not include inactive chunks backed by swap
|
|||
|
|
files. This does not include inactive chunks embedded in the DSS.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.chunks.total</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of chunks allocated.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.chunks.high</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Maximum number of active chunks at any time thus far.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.huge.allocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of bytes currently allocated by huge objects.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.huge.nmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of huge allocation requests.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.huge.ndalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of huge deallocation requests.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.nthreads</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">unsigned</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of threads currently assigned to
|
|||
|
|
arena.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.pactive</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of pages in active runs.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.pdirty</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
</span></dt><dd><p>Number of pages within unused runs that are potentially
|
|||
|
|
dirty, and for which <code class="function">madvise</code>(<em class="parameter"><code>...</code></em>,
|
|||
|
|
<em class="parameter"><code><code class="constant">MADV_DONTNEED</code></code></em>) or
|
|||
|
|
similar has not been called.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.mapped</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of mapped bytes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.npurge</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of dirty page purge sweeps performed.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.nmadvise</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of <code class="function">madvise</code>(<em class="parameter"><code>...</code></em>,
|
|||
|
|
<em class="parameter"><code><code class="constant">MADV_DONTNEED</code></code></em>) or
|
|||
|
|
similar calls made to purge dirty pages.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.npurged</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of pages purged.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.small.allocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of bytes currently allocated by small objects.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.small.nmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of allocation requests served by
|
|||
|
|
small bins.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.small.ndalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of small objects returned to bins.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.small.nrequests</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of small allocation requests.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.large.allocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Number of bytes currently allocated by large objects.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.large.nmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of large allocation requests served
|
|||
|
|
directly by the arena.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.large.ndalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of large deallocation requests served
|
|||
|
|
directly by the arena.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.large.nrequests</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of large allocation requests.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.allocated</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Current number of bytes allocated by
|
|||
|
|
bin.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.nmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of allocations served by bin.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.ndalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of allocations returned to bin.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.nrequests</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of allocation
|
|||
|
|
requests.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.nfills</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code> <code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of tcache fills.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.nflushes</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code> <code class="option">--enable-tcache</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of tcache flushes.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.nruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of runs created.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.nreruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of times the current run from which
|
|||
|
|
to allocate changed.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.highruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Maximum number of runs at any time thus far.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.bins.<j>.curruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Current number of runs.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.lruns.<j>.nmalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of allocation requests for this size
|
|||
|
|
class served directly by the arena.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.lruns.<j>.ndalloc</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of deallocation requests for this
|
|||
|
|
size class served directly by the arena.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.lruns.<j>.nrequests</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">uint64_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Cumulative number of allocation requests for this size
|
|||
|
|
class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.lruns.<j>.highruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Maximum number of runs at any time thus far for this
|
|||
|
|
size class.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">stats.arenas.<i>.lruns.<j>.curruns</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats</code>]
|
|||
|
|
</span></dt><dd><p>Current number of runs for this size class.
|
|||
|
|
</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">swap.avail</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-stats --enable-swap</code>]
|
|||
|
|
</span></dt><dd><p>Number of swap file bytes that are currently not
|
|||
|
|
associated with any chunk (i.e. mapped, but otherwise completely
|
|||
|
|
unmanaged).</p></dd><dt><a name="swap.prezeroed"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">swap.prezeroed</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">bool</span>)
|
|||
|
|
<code class="literal">rw</code>
|
|||
|
|
[<code class="option">--enable-swap</code>]
|
|||
|
|
</span></dt><dd><p>If true, the allocator assumes that the swap file(s)
|
|||
|
|
contain nothing but nil bytes. If this assumption is violated,
|
|||
|
|
allocator behavior is undefined. This value becomes read-only after
|
|||
|
|
<a class="link" href="#swap.fds">
|
|||
|
|
"<code class="mallctl">swap.fds</code>"
|
|||
|
|
</a> is
|
|||
|
|
successfully written to.</p></dd><dt><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">swap.nfds</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">size_t</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-swap</code>]
|
|||
|
|
</span></dt><dd><p>Number of file descriptors in use for swap.
|
|||
|
|
</p></dd><dt><a name="swap.fds"></a><span class="term">
|
|||
|
|
|
|||
|
|
"<code class="mallctl">swap.fds</code>"
|
|||
|
|
|
|||
|
|
(<span class="type">int *</span>)
|
|||
|
|
<code class="literal">r-</code>
|
|||
|
|
[<code class="option">--enable-swap</code>]
|
|||
|
|
</span></dt><dd><p>When written to, the files associated with the
|
|||
|
|
specified file descriptors are contiguously mapped via
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">mmap</span>(2)</span>. The resulting virtual memory
|
|||
|
|
region is preferred over anonymous
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">mmap</span>(2)</span> and
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">sbrk</span>(2)</span> memory. Note that if a file's
|
|||
|
|
size is not a multiple of the page size, it is automatically truncated
|
|||
|
|
to the nearest page size multiple. See the
|
|||
|
|
<a class="link" href="#swap.prezeroed">
|
|||
|
|
"<code class="mallctl">swap.prezeroed</code>"
|
|||
|
|
</a>
|
|||
|
|
mallctl for specifying that the files are pre-zeroed.</p></dd></dl></div></div><div class="refsect1" title="DEBUGGING MALLOC PROBLEMS"><a name="debugging_malloc_problems"></a><h2>DEBUGGING MALLOC PROBLEMS</h2><p>When debugging, it is a good idea to configure/build jemalloc with
|
|||
|
|
the <code class="option">--enable-debug</code> and <code class="option">--enable-fill</code>
|
|||
|
|
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.</p><p>Programs often accidentally depend on “uninitialized”
|
|||
|
|
memory actually being filled with zero bytes. Junk filling
|
|||
|
|
(see the <a class="link" href="#opt.junk">
|
|||
|
|
"<code class="mallctl">opt.junk</code>"
|
|||
|
|
</a>
|
|||
|
|
option) tends to expose such bugs in the form of obviously incorrect
|
|||
|
|
results and/or coredumps. Conversely, zero
|
|||
|
|
filling (see the <a class="link" href="#opt.zero">
|
|||
|
|
"<code class="mallctl">opt.zero</code>"
|
|||
|
|
</a> option) eliminates
|
|||
|
|
the symptoms of such bugs. Between these two options, it is usually
|
|||
|
|
possible to quickly detect, diagnose, and eliminate such bugs.</p><p>This implementation does not provide much detail about the problems
|
|||
|
|
it detects, because the performance impact for storing such information
|
|||
|
|
would be prohibitive. There are a number of allocator implementations
|
|||
|
|
available on the Internet which focus on detecting and pinpointing problems
|
|||
|
|
by trading performance for extra sanity checks and detailed
|
|||
|
|
diagnostics.</p></div><div class="refsect1" title="DIAGNOSTIC MESSAGES"><a name="diagnostic_messages"></a><h2>DIAGNOSTIC MESSAGES</h2><p>If any of the memory allocation/deallocation functions detect an
|
|||
|
|
error or warning condition, a message will be printed to file descriptor
|
|||
|
|
<code class="constant">STDERR_FILENO</code>. Errors will result in the process
|
|||
|
|
dumping core. If the <a class="link" href="#opt.abort">
|
|||
|
|
"<code class="mallctl">opt.abort</code>"
|
|||
|
|
</a> option is set, most
|
|||
|
|
warnings are treated as errors.</p><p>The <code class="varname">malloc_message</code> variable allows the programmer
|
|||
|
|
to override the function which emits the text strings forming the errors
|
|||
|
|
and warnings if for some reason the <code class="constant">STDERR_FILENO</code> file
|
|||
|
|
descriptor is not suitable for this.
|
|||
|
|
<code class="function">malloc_message</code>(<em class="parameter"><code></code></em>) takes the
|
|||
|
|
<em class="parameter"><code>cbopaque</code></em> pointer argument that is
|
|||
|
|
<code class="constant">NULL</code> unless overridden by the arguments in a call to
|
|||
|
|
<code class="function">malloc_stats_print</code>(<em class="parameter"><code></code></em>), 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.</p><p>All messages are prefixed by
|
|||
|
|
“<code class="computeroutput"><jemalloc>: </code>”.</p></div><div class="refsect1" title="RETURN VALUES"><a name="return_values"></a><h2>RETURN VALUES</h2><div class="refsect2" title="Standard API"><a name="id2844722"></a><h3>Standard API</h3><p>The <code class="function">malloc</code>(<em class="parameter"><code></code></em>) and
|
|||
|
|
<code class="function">calloc</code>(<em class="parameter"><code></code></em>) functions return a pointer to the
|
|||
|
|
allocated memory if successful; otherwise a <code class="constant">NULL</code>
|
|||
|
|
pointer is returned and <code class="varname">errno</code> is set to
|
|||
|
|
<span class="errorname">ENOMEM</span>.</p><p>The <code class="function">posix_memalign</code>(<em class="parameter"><code></code></em>) function
|
|||
|
|
returns the value 0 if successful; otherwise it returns an error value.
|
|||
|
|
The <code class="function">posix_memalign</code>(<em class="parameter"><code></code></em>) function will fail
|
|||
|
|
if:
|
|||
|
|
</p><div class="variablelist"><dl><dt><span class="term"><span class="errorname">EINVAL</span></span></dt><dd><p>The <em class="parameter"><code>alignment</code></em> parameter is
|
|||
|
|
not a power of 2 at least as large as
|
|||
|
|
<code class="code">sizeof(<span class="type">void *</span>)</code>.
|
|||
|
|
</p></dd><dt><span class="term"><span class="errorname">ENOMEM</span></span></dt><dd><p>Memory allocation error.</p></dd></dl></div><p>
|
|||
|
|
</p><p>The <code class="function">realloc</code>(<em class="parameter"><code></code></em>) function returns a
|
|||
|
|
pointer, possibly identical to <em class="parameter"><code>ptr</code></em>, to the
|
|||
|
|
allocated memory if successful; otherwise a <code class="constant">NULL</code>
|
|||
|
|
pointer is returned, and <code class="varname">errno</code> is set to
|
|||
|
|
<span class="errorname">ENOMEM</span> if the error was the result of an
|
|||
|
|
allocation failure. The <code class="function">realloc</code>(<em class="parameter"><code></code></em>)
|
|||
|
|
function always leaves the original buffer intact when an error occurs.
|
|||
|
|
</p><p>The <code class="function">free</code>(<em class="parameter"><code></code></em>) function returns no
|
|||
|
|
value.</p></div><div class="refsect2" title="Non-standard API"><a name="id2844875"></a><h3>Non-standard API</h3><p>The <code class="function">malloc_usable_size</code>(<em class="parameter"><code></code></em>) function
|
|||
|
|
returns the usable size of the allocation pointed to by
|
|||
|
|
<em class="parameter"><code>ptr</code></em>. </p><p>The <code class="function">mallctl</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">mallctlnametomib</code>(<em class="parameter"><code></code></em>), and
|
|||
|
|
<code class="function">mallctlbymib</code>(<em class="parameter"><code></code></em>) functions return 0 on
|
|||
|
|
success; otherwise they return an error value. The functions will fail
|
|||
|
|
if:
|
|||
|
|
</p><div class="variablelist"><dl><dt><span class="term"><span class="errorname">EINVAL</span></span></dt><dd><p><em class="parameter"><code>newp</code></em> is not
|
|||
|
|
<code class="constant">NULL</code>, and <em class="parameter"><code>newlen</code></em> is too
|
|||
|
|
large or too small. Alternatively, <em class="parameter"><code>*oldlenp</code></em>
|
|||
|
|
is too large or too small; in this case as much data as possible
|
|||
|
|
are read despite the error.</p></dd><dt><span class="term"><span class="errorname">ENOMEM</span></span></dt><dd><p><em class="parameter"><code>*oldlenp</code></em> is too short to
|
|||
|
|
hold the requested value.</p></dd><dt><span class="term"><span class="errorname">ENOENT</span></span></dt><dd><p><em class="parameter"><code>name</code></em> or
|
|||
|
|
<em class="parameter"><code>mib</code></em> specifies an unknown/invalid
|
|||
|
|
value.</p></dd><dt><span class="term"><span class="errorname">EPERM</span></span></dt><dd><p>Attempt to read or write void value, or attempt to
|
|||
|
|
write read-only value.</p></dd><dt><span class="term"><span class="errorname">EAGAIN</span></span></dt><dd><p>A memory allocation failure
|
|||
|
|
occurred.</p></dd><dt><span class="term"><span class="errorname">EFAULT</span></span></dt><dd><p>An interface with side effects failed in some way
|
|||
|
|
not directly related to <code class="function">mallctl*</code>(<em class="parameter"><code></code></em>)
|
|||
|
|
read/write processing.</p></dd></dl></div><p>
|
|||
|
|
</p></div><div class="refsect2" title="Experimental API"><a name="id2845053"></a><h3>Experimental API</h3><p>The <code class="function">allocm</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">rallocm</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">sallocm</code>(<em class="parameter"><code></code></em>), and
|
|||
|
|
<code class="function">dallocm</code>(<em class="parameter"><code></code></em>) functions return
|
|||
|
|
<code class="constant">ALLOCM_SUCCESS</code> on success; otherwise they return an
|
|||
|
|
error value. The <code class="function">allocm</code>(<em class="parameter"><code></code></em>) and
|
|||
|
|
<code class="function">rallocm</code>(<em class="parameter"><code></code></em>) functions will fail if:
|
|||
|
|
</p><div class="variablelist"><dl><dt><span class="term"><span class="errorname">ALLOCM_ERR_OOM</span></span></dt><dd><p>Out of memory. Insufficient contiguous memory was
|
|||
|
|
available to service the allocation request. The
|
|||
|
|
<code class="function">allocm</code>(<em class="parameter"><code></code></em>) function additionally sets
|
|||
|
|
<em class="parameter"><code>*ptr</code></em> to <code class="constant">NULL</code>, whereas
|
|||
|
|
the <code class="function">rallocm</code>(<em class="parameter"><code></code></em>) function leaves
|
|||
|
|
<code class="constant">*ptr</code> unmodified.</p></dd></dl></div><p>
|
|||
|
|
The <code class="function">rallocm</code>(<em class="parameter"><code></code></em>) function will also
|
|||
|
|
fail if:
|
|||
|
|
</p><div class="variablelist"><dl><dt><span class="term"><span class="errorname">ALLOCM_ERR_NOT_MOVED</span></span></dt><dd><p><code class="constant">ALLOCM_NO_MOVE</code> was specified,
|
|||
|
|
but the reallocation request could not be serviced without moving
|
|||
|
|
the object.</p></dd></dl></div><p>
|
|||
|
|
</p></div></div><div class="refsect1" title="ENVIRONMENT"><a name="environment"></a><h2>ENVIRONMENT</h2><p>The following environment variable affects the execution of the
|
|||
|
|
allocation functions:
|
|||
|
|
</p><div class="variablelist"><dl><dt><span class="term"><code class="envar">MALLOC_CONF</code></span></dt><dd><p>If the environment variable
|
|||
|
|
<code class="envar">MALLOC_CONF</code> is set, the characters it contains
|
|||
|
|
will be interpreted as options.</p></dd></dl></div><p>
|
|||
|
|
</p></div><div class="refsect1" title="EXAMPLES"><a name="examples"></a><h2>EXAMPLES</h2><p>To dump core whenever a problem occurs:
|
|||
|
|
</p><pre class="screen">ln -s 'abort:true' /etc/malloc.conf</pre><p>
|
|||
|
|
</p><p>To specify in the source a chunk size that is 16 MiB:
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
malloc_conf = "lg_chunk:24";</pre></div><div class="refsect1" title="SEE ALSO"><a name="see_also"></a><h2>SEE ALSO</h2><p><span class="citerefentry"><span class="refentrytitle">madvise</span>(2)</span>,
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">mmap</span>(2)</span>,
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">sbrk</span>(2)</span>,
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">alloca</span>(3)</span>,
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">atexit</span>(3)</span>,
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">getpagesize</span>(3)</span></p></div><div class="refsect1" title="STANDARDS"><a name="standards"></a><h2>STANDARDS</h2><p>The <code class="function">malloc</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">calloc</code>(<em class="parameter"><code></code></em>),
|
|||
|
|
<code class="function">realloc</code>(<em class="parameter"><code></code></em>), and
|
|||
|
|
<code class="function">free</code>(<em class="parameter"><code></code></em>) functions conform to ISO/IEC
|
|||
|
|
9899:1990 (“ISO C90”).</p><p>The <code class="function">posix_memalign</code>(<em class="parameter"><code></code></em>) function conforms
|
|||
|
|
to IEEE Std 1003.1-2001 (“POSIX.1”).</p></div></div></body></html>
|