148 lines
7.2 KiB
HTML
148 lines
7.2 KiB
HTML
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<!-- This file documents the gprof profiler of the GNU system.
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Copyright (C) 1988-2016 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3
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or any later version published by the Free Software Foundation;
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with no Invariant Sections, with no Front-Cover Texts, and with no
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Back-Cover Texts. A copy of the license is included in the
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section entitled "GNU Free Documentation License".
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-->
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<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>GNU gprof: Call Graph</title>
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<meta name="description" content="GNU gprof: Call Graph">
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<meta name="keywords" content="GNU gprof: Call Graph">
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<meta name="resource-type" content="document">
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<meta name="distribution" content="global">
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<meta name="Generator" content="makeinfo">
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<link href="index.html#Top" rel="start" title="Top">
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<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="Output.html#Output" rel="up" title="Output">
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<link href="Primary.html#Primary" rel="next" title="Primary">
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<link href="Flat-Profile.html#Flat-Profile" rel="prev" title="Flat Profile">
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<style type="text/css">
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</style>
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</head>
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<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
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<a name="Call-Graph"></a>
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<div class="header">
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<p>
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Next: <a href="Line_002dby_002dline.html#Line_002dby_002dline" accesskey="n" rel="next">Line-by-line</a>, Previous: <a href="Flat-Profile.html#Flat-Profile" accesskey="p" rel="prev">Flat Profile</a>, Up: <a href="Output.html#Output" accesskey="u" rel="up">Output</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>]</p>
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</div>
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<hr>
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<a name="The-Call-Graph"></a>
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<h3 class="section">5.2 The Call Graph</h3>
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<a name="index-call-graph"></a>
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<p>The <em>call graph</em> shows how much time was spent in each function
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and its children. From this information, you can find functions that,
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while they themselves may not have used much time, called other
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functions that did use unusual amounts of time.
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</p>
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<p>Here is a sample call from a small program. This call came from the
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same <code>gprof</code> run as the flat profile example in the previous
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section.
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</p>
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<div class="smallexample">
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<pre class="smallexample">granularity: each sample hit covers 2 byte(s) for 20.00% of 0.05 seconds
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index % time self children called name
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<spontaneous>
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[1] 100.0 0.00 0.05 start [1]
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0.00 0.05 1/1 main [2]
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0.00 0.00 1/2 on_exit [28]
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0.00 0.00 1/1 exit [59]
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-----------------------------------------------
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0.00 0.05 1/1 start [1]
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[2] 100.0 0.00 0.05 1 main [2]
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0.00 0.05 1/1 report [3]
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-----------------------------------------------
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0.00 0.05 1/1 main [2]
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[3] 100.0 0.00 0.05 1 report [3]
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0.00 0.03 8/8 timelocal [6]
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0.00 0.01 1/1 print [9]
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0.00 0.01 9/9 fgets [12]
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0.00 0.00 12/34 strncmp <cycle 1> [40]
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0.00 0.00 8/8 lookup [20]
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0.00 0.00 1/1 fopen [21]
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0.00 0.00 8/8 chewtime [24]
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0.00 0.00 8/16 skipspace [44]
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-----------------------------------------------
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[4] 59.8 0.01 0.02 8+472 <cycle 2 as a whole> [4]
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0.01 0.02 244+260 offtime <cycle 2> [7]
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0.00 0.00 236+1 tzset <cycle 2> [26]
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-----------------------------------------------
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</pre></div>
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<p>The lines full of dashes divide this table into <em>entries</em>, one for each
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function. Each entry has one or more lines.
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</p>
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<p>In each entry, the primary line is the one that starts with an index number
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in square brackets. The end of this line says which function the entry is
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for. The preceding lines in the entry describe the callers of this
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function and the following lines describe its subroutines (also called
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<em>children</em> when we speak of the call graph).
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</p>
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<p>The entries are sorted by time spent in the function and its subroutines.
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</p>
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<p>The internal profiling function <code>mcount</code> (see <a href="Flat-Profile.html#Flat-Profile">The
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Flat Profile</a>) is never mentioned in the call graph.
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</p>
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<table class="menu" border="0" cellspacing="0">
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<tr><td align="left" valign="top">• <a href="Primary.html#Primary" accesskey="1">Primary</a>:</td><td> </td><td align="left" valign="top">Details of the primary line’s contents.
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Callers.html#Callers" accesskey="2">Callers</a>:</td><td> </td><td align="left" valign="top">Details of caller-lines’ contents.
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Subroutines.html#Subroutines" accesskey="3">Subroutines</a>:</td><td> </td><td align="left" valign="top">Details of subroutine-lines’ contents.
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Cycles.html#Cycles" accesskey="4">Cycles</a>:</td><td> </td><td align="left" valign="top">When there are cycles of recursion,
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such as <code>a</code> calls <code>b</code> calls <code>a</code>…
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</td></tr>
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</table>
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<hr>
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<div class="header">
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<p>
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Next: <a href="Line_002dby_002dline.html#Line_002dby_002dline" accesskey="n" rel="next">Line-by-line</a>, Previous: <a href="Flat-Profile.html#Flat-Profile" accesskey="p" rel="prev">Flat Profile</a>, Up: <a href="Output.html#Output" accesskey="u" rel="up">Output</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>]</p>
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</div>
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</body>
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</html>
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