<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta name="robots" content="index,nofollow"> <title>ProfilingTheStack - MLton Standard ML Compiler (SML Compiler)</title> <link rel="stylesheet" type="text/css" charset="iso-8859-1" media="all" href="common.css"> <link rel="stylesheet" type="text/css" charset="iso-8859-1" media="screen" href="screen.css"> <link rel="stylesheet" type="text/css" charset="iso-8859-1" media="print" href="print.css"> <link rel="Start" href="Home"> </head> <body lang="en" dir="ltr"> <script src="http://www.google-analytics.com/urchin.js" type="text/javascript"> </script> <script type="text/javascript"> _uacct = "UA-833377-1"; urchinTracker(); </script> <table bgcolor = lightblue cellspacing = 0 style = "border: 0px;" width = 100%> <tr> <td style = " border: 0px; color: darkblue; font-size: 150%; text-align: left;"> <a class = mltona href="Home">MLton MLTONWIKIVERSION</a> <td style = " border: 0px; font-size: 150%; text-align: center; width: 50%;"> ProfilingTheStack <td style = " border: 0px; text-align: right;"> <table cellspacing = 0 style = "border: 0px"> <tr style = "vertical-align: middle;"> </table> <tr style = "background-color: white;"> <td colspan = 3 style = " border: 0px; font-size:70%; text-align: right;"> <a href = "Home">Home</a> <a href = "TitleIndex">Index</a> </table> <div id="content" lang="en" dir="ltr"> For all forms of <a href="Profiling">Profiling</a>, you can gather counts for all functions on the stack, not just the currently executing function. To do so, compile your program with <tt>-profile-stack true</tt>. For example, suppose that <tt>list-rev.sml</tt> contains the following. <p> <pre class=code><B><FONT COLOR="#A020F0">fun</FONT></B> append (l1, l2) = <B><FONT COLOR="#A020F0">case</FONT></B> l1 <B><FONT COLOR="#A020F0">of</FONT></B> [] => l2 | x :: l1 => x :: append (l1, l2) <B><FONT COLOR="#A020F0">fun</FONT></B> rev l = <B><FONT COLOR="#A020F0">case</FONT></B> l <B><FONT COLOR="#A020F0">of</FONT></B> [] => [] | x :: l => append (rev l, [x]) <B><FONT COLOR="#A020F0">val</FONT></B> l = List.tabulate (<B><FONT COLOR="#5F9EA0">1000</FONT></B>, <B><FONT COLOR="#A020F0">fn</FONT></B> i => i) <B><FONT COLOR="#A020F0">val</FONT></B> _ = <B><FONT COLOR="#5F9EA0">1</FONT></B> + hd (rev l) </PRE> </p> <p> Compile with stack profiling and then run the program. <pre>% mlton -profile alloc -profile-stack true list-rev.sml % ./list-rev </pre> </p> <p> Display the profiling data. </p> <pre>% mlprof -show-line true list-rev mlmon.out 6,030,136 bytes allocated (108,336 bytes by GC) function cur stack GC ----------------------- ----- ----- ---- append list-rev.sml: 1 97.6% 97.6% 1.4% <gc> 1.8% 0.0% 1.8% <main> 0.4% 98.2% 1.8% rev list-rev.sml: 6 0.2% 97.6% 1.8% </pre><p> In the above table, we see that <tt>rev</tt>, defined on line 6 of <tt>list-rev.sml</tt>, is only responsible for 0.2% of the allocation, but is on the stack while 97.6% of the allocation is done by the user program and while 1.8% of the allocation is done by the garbage collector. </p> <p> The run-time performance impact of <tt>-profile-stack true</tt> can be noticeable since there is some extra bookkeeping at every nontail call and return. </p> </div> <p> <hr> Last edited on 2006-11-02 17:42:31 by <span title="76.16.241.4"><a href="MatthewFluet">MatthewFluet</a></span>. </body></html>