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diff --git a/tools/jprof/README.html b/tools/jprof/README.html deleted file mode 100644 index 2ae88dec4..000000000 --- a/tools/jprof/README.html +++ /dev/null @@ -1,330 +0,0 @@ -<!-- This Source Code Form is subject to the terms of the Mozilla Public - - License, v. 2.0. If a copy of the MPL was not distributed with this - - file, You can obtain one at http://mozilla.org/MPL/2.0/. --> - -<html> -<head><title>The Jprof Profiler</title></head> - -<body bgcolor="#FFFFFF" text="#000000" - link="#0000EE" vlink="#551A8B" alink="#FF0000"> -<center> -<h1>The Jprof Profiler</h1> -<font size="-1"> -<a href="mailto:jim_nance%yahoo.com">jim_nance@yahoo.com</a><p> -Recent (4/2011) updates Randell Jesup (see bugzilla for contact info) -</font> -<hr> - -<a href="#introduction">Introduction</a> | <a href="#operation">Operation</a> | -<a href="#setup">Setup</a> | <a href="#usage">Usage</a> | -<a href="#interpretation">Interpretation</a> - -</center> -<hr> - -<h3><a name="introduction">Introduction</a></h3> - -Jprof is a profiling tool. I am writing it because I need to find out -where mozilla is spending its time, and there do not seem to be any -profilers for Linux that can handle threads and/or shared libraries. -This code is based heavily on Kipp Hickman's leaky. - -<h3><a name="operation">Operation</a></h3> - -Jprof operates by installing a timer which periodically interrupts mozilla. -When this timer goes off, the jprof code inside mozilla walks the function call -stack to determine which code was executing and saves the results into the -<code>jprof-log</code> and <code>jprof-map</code> files. By collecting a large -number of these call stacks, it is possible to deduce where mozilla is spending -its time. - -<h3><a name="setup">Setup</a></h3> - -<p>Configure your mozilla with jprof support by adding -<code>--enable-jprof</code> to your configure options (eg adding -<code>ac_add_options --enable-jprof</code> to your <code>.mozconfig</code>) and -making sure that you do <strong>not</strong> have the -<code>--enable-strip</code> configure option set -- jprof needs symbols to -operate. On many architectures with GCC, you'll need to add -<code>--enable-optimize="-O3 -fno-omit-frame-pointer"</code> or the -equivalent to ensure frame pointer generation in the compiler you're using.</p> - -<p>Finally, build mozilla with your new configuration. Now you can run jprof.</p> - -<h3><a name="usage">Usage</a></h3> -<pre> jprof [-v] [-t] [-e exclude] [-i include] [-s stackdepth] [--last] [--all] [--start n [--end m]] [--output-dir dir] prog log [log2 ...]</pre> -Options: -<ul> - <li><b>-s depth</b> : Limit depth looked at from captured stack - frames</li> - <li><b>-v</b> : Output some information about the symbols, memory map, etc.</li> - <li><b>-t or --threads</b> : Group output according to thread. May require external - LD_PRELOAD library to help force sampling of spawned threads; jprof - may capture the main thread only. See <a - href="http://sam.zoy.org/writings/programming/gprof.html">gprof-helper</a>; - it may need adaption for jprof.</li> - <li><b>--only-thread id</b> : Only output data for thread 'id'</li> - <li><b>-e exclusion</b> : Allows excluding specific stack frames</li> - <li><b>-i inclusion</b> : Allows including specific stack frames</li> - <li><b>--last</b> : Only process data from the last 'section' of sampling - (starting at the last PROF)</li> - <li><b>--start N</b> : Start processing data at 'section' N </li> - <li><b>--end N</b> : Stop processing data at 'section' N </li> - <li><b>--output-dir dir</b> : Store generated .html files in the given directory </li> -</ul> -The behavior of jprof is determined by the value of the JPROF_FLAGS environment -variable. This environment variable can be composed of several substrings -which have the following meanings: -<ul> - <li> <b>JP_START</b> : Install the signal handler, and start sending the - timer signals. - - <li> <b>JP_DEFER</b> : Install the signal handler, but don't start sending - the timer signals. The user must start the signals by sending the first - one (with <code>kill -PROF</code>, or with <code>kill -ALRM</code> if - JP_REALTIME is used, or with <code>kill -POLL</code> (also known as <code>kill -IO</code>) if JP_RTC_HZ is used). - - <li> <b>JP_FIRST=x</b> : Wait x seconds before starting the timer - - <li> <b>JP_PERIOD=y</b> : Set timer to interrupt every y seconds. Only - values of y greater than or equal to 0.001 are supported. Default is - 0.050 (50ms). - - <li> <b>JP_REALTIME</b> : Do the profiling in intervals of real time rather - than intervals of time used by the mozilla process (and the kernel - when doing work for mozilla). This could probably lead to weird - results (you'll see whatever runs when mozilla is waiting for events), - but is needed to see time spent in the X server. - - <li> <b>JP_RTC_HZ=freq</b> : This option, only available on Linux if the - kernel is built with RTC support, makes jprof use the RTC timer instead of - using its own timer. This option, like JP_REALTIME, uses intervals of real - time. This option overrides JP_PERIOD. <code>freq</code> is the frequency - at which the timer should fire, measured in Hz. It must be a power of 2. - The maximal frequency allowed by the kernel can be changed by writing to - <code>/proc/sys/dev/rtc/max-user-freq</code>; the maximum value it can be - set to is 8192. Note that <code>/dev/rtc</code> will need to be readable - by the Firefox process; making that file world-readable is a simple way to - accomplish that. - - <li> <b>JP_CIRCULAR=size</b> : This tells jprof to store samples in a - circular buffer of the given size, which then will be saved (appended) - to disk when SIGUSR1 is received or JProfStopProfiling is done. If the - buffer overflows, the oldest entries will be evicted until there's - space for the new entry.<p> - - SIGUSR2 will cause the circular buffer to be cleared. - - <li> <b>JP_FILENAME=basefilename</b> : This is the filename used for - saving the log files to; the default is "jprof-log". If Electrolysis - is used, each process after the first will have the process ID - added ("jprof-log-3212"); - -</ul> - -<h4>Starting and stopping jprof from JavaScript</h4> -<p> -A build with jprof enabled adds four functions to the Window object:<p> -<code>JProfStartProfiling()</code> and <code>JProfStopProfiling()</code>: When used with JP_DEFER, these -allow one to start and stop the timer just around whatever critical section is -being profiled.</p><p> -<code>JProfClearCircular()</code> and <code>JProfSaveCircular()</code>: -These clear the circular buffer and save the buffer (without stopping), respectively.</p> - -<h4>Examples of JPROF_FLAGS usage</h4> -<ul> - - <li>To make the timer start firing 3 seconds after the program is started and - fire every 25 milliseconds of program time use: - <pre> - setenv JPROF_FLAGS "JP_START JP_FIRST=3 JP_PERIOD=0.025" </pre> - - <li>To make the timer start on your signal and fire every 1 millisecond of - program time use: - <pre> - setenv JPROF_FLAGS "JP_DEFER JP_PERIOD=0.001" </pre> - - <li>To make the timer start on your signal and fire every 10 milliseconds of - wall-clock time use: - <pre> - setenv JPROF_FLAGS "JP_DEFER JP_PERIOD=0.010 JP_REALTIME" </pre> - - <li>To make the timer start on your signal and fire at 8192 Hz in wall-clock - time use: - <pre> - setenv JPROF_FLAGS "JP_DEFER JP_RTC_HZ=8192" </pre> - - <li>To make the timer start on JProfStartProfiling() and run continously - with a 1ms sample rate until told to stop, then save the last 1MB of - data: - <pre> - setenv JPROF_FLAGS "JP_DEFER JP_CIRCULAR=1048576 JP_PERIOD=0.001" </pre> - -</ul> - -<h4>Pausing profiles</h4> - -<P>jprof can be paused at any time by sending a SIGUSR1 to mozilla (<code>kill --USR1</code>). This will cause the timer signals to stop and jprof-map to be -written, but it will not close jprof-log. Combining SIGUSR1 with the JP_DEFER -option allows profiling of one sequence of actions by starting the timer right -before starting the actions and stopping the timer right afterward. - -<P>After a SIGUSR1, sending another timer signal (SIGPROF, SIGALRM, or SIGPOLL (aka SIGIO), -depending on the mode) can be used to continue writing data to the same -output. - -<P>SIGUSR2 will cause the circular buffer to be cleared, if it's in use. -This is useful right before running a test when you're using a large, -continuous circular buffer, or programmatically at the start of an action -which might take too long (JProfClearCircular()). - -<h4>Looking at the results</h4> - -Now that we have <code>jprof-log</code> and <code>jprof-map</code> files, we -can use the jprof executable is used to turn them into readable output. To do -this jprof needs the name of the mozilla binary and the log file. It deduces -the name of the map file: - -<pre> - ./jprof /home/user/mozilla/objdir/dist/bin/firefox ./jprof-log > tmp.html -</pre> - -This will generate the file <code>tmp.html</code> which you should view in a -web browser. - -<pre> - ./jprof --output-dir=/tmp /home/user/mozilla/objdir/dist/bin/firefox ./jprof-log* -</pre> - -This will generate a set of files in /tmp for each process. - - -<h3><a name="interpretation">Interpretation</a></h3> - - -The Jprof output is split into a flat portion and a hierarchical portion. -There are links to each section at the top of the page. It is typically -easier to analyze the profile by starting with the flat output and following -the links contained in the flat output up to the hierarchical output. - -<h4><a name="flat">Flat output</a></h3> - -The flat portion of the profile indicates which functions were executing -when the timer was going off. It is displayed as a list of functions names -on the right and the number of times that function was interrupted on the -left. The list is sorted by decreasing interrupt count. For example: - -<blockquote> <pre> -Total hit count: 151603 -Count %Total Function Name - -<a href="#23081">8806 5.8 __libc_poll</a> -<a href="#40008">2254 1.5 __i686.get_pc_thunk.bx</a> -<a href="#21390">2053 1.4 _int_malloc</a> -<a href="#49013">1777 1.2 nsStyleContext::GetStyleData(nsStyleStructID)</a> -<a href="#21380">1600 1.1 __libc_malloc</a> -<a href="#603">1552 1.0 nsCOMPtr_base::~nsCOMPtr_base()</a> -</pre> </blockquote> - -This shows that of the 151603 times the timer fired, 1777 (1.2% of the total) were inside nsStyleContext::GetStyleData() and 1552 (1.0% of the total) were in the nsCOMPtr_base destructor. - -<p> -In general, the functions with the highest count are the functions which -are taking the most time. - -<P> -The function names are linked to the entry for that function in the -hierarchical profile, which is described in the next section. - -<h4><a name="hier">Hierarchical output</a></h4> - -The hierarchical output is divided up into sections, with each section -corresponding to one function. A typical section looks something like -this: - -<blockquote><pre> - index Count Hits Function Name - <A href="#72871"> 545 (46.4%) nsBlockFrame::ReflowInlineFrames(nsBlockReflowState&, nsLineList_iterator, int*)</A> - <A href="#72873"> 100 (8.5%) nsBlockFrame::ReflowDirtyLines(nsBlockReflowState&)</A> - 72870 4 (0.3%) <a name=72870> 645 (54.9%)</a> <b>nsBlockFrame::DoReflowInlineFrames(nsBlockReflowState&, nsLineLayout&, nsLineList_iterator, nsFlowAreaRect&, int&, nsFloatManager::SavedState*, int*, LineReflowStatus*, int)</b> - <A href="#72821"> 545 (46.4%) nsBlockFrame::ReflowInlineFrame(nsBlockReflowState&, nsLineLayout&, nsLineList_iterator, nsIFrame*, LineReflowStatus*)</A> - <A href="#72853"> 83 (7.1%) nsBlockFrame::PlaceLine(nsBlockReflowState&, nsLineLayout&, nsLineList_iterator, nsFloatManager::SavedState*, nsRect&, int&, int*)</A> - <A href="#74150"> 9 (0.8%) nsLineLayout::BeginLineReflow(int, int, int, int, int, int)</A> - <A href="#74897"> 1 (0.1%) nsTextFrame::GetType() const</A> - <A href="#74131"> 1 (0.1%) nsLineLayout::RelativePositionFrames(nsOverflowAreas&)</A> - <A href="#58320"> 1 (0.1%) __i686.get_pc_thunk.bx</A> - <A href="#53077"> 1 (0.1%) PL_ArenaAllocate</A> -</pre></blockquote> - -The information this block tells us is: - -<ul> -<li>There were 4 profiler hits <em>in</em> <code>nsBlockFrame::DoReflowInlineFrames</code> -<li>There were 645 profiler hits <em>in or under</em> <code>nsBlockFrame::DoReflowInlineFrames</code>. Of these: -<ul> - <li>545 were in or under <code>nsBlockFrame::ReflowInlineFrame</code> - <li>83 were in or under <code>nsBlockFrame::PlaceLine</code> - <li>9 were in or under <code>nsLineLayout::BeginLineReflow</code> - <li>1 was in or under <code>nsTextFrame::GetType</code> - <li>1 was in or under <code>nsLineLayout::RelativePositionFrames</code> - <li>1 was in or under <code>__i686.get_pc_thunk.bx</code> - <li>1 was in or under <code>PL_ArenaAllocate</code> -</ul> -<li>Of these 645 calls into <code>nsBlockFrame::DoReflowInlineFrames</code>: -<ul> - <li>545 came from <code>nsBlockFrame::ReflowInlineFrames</code> - <li>100 came from <code>nsBlockFrame::ReflowDirtyLines</code> -</ul> -</ul> - - -The rest of this section explains how to read this information off from the jprof output. - -<p>This block corresponds to the function <code>nsBlockFrame::DoReflowInlineFrames</code>, which is -therefore bolded and not a link. The name of this function is preceded by -five numbers which have the following meaning. The number on the left (72870) -is the index number, and is not important. The next number (4) and the -percentage following (0.3%) are the number -of times this function was interrupted by the timer and the percentage of -the total hits that is. The last number pair ("645 (54.9%)") -are the number of times this function was in the call stack when the timer went -off. That is, the timer went off while we were in code that was ultimately -called from <code>nsBlockFrame::DoReflowInlineFrames</code>. -<p>For our example we can see that our function was in the call stack for -645 interrupt ticks, but we were only the function that was running when -the interrupt arrived 4 times. -<P> -The functions listed above the line for <code>nsBlockFrame::DoReflowInlineFrames</code> are its -callers. The numbers to the left of these function names are the numbers of -times these functions were in the call stack as callers of -<code>nsBlockFrame::DoReflowInlineFrames</code>. In our example, we were called 545 times by -<code>nsBlockFrame::ReflowInlineFrames</code> and 100 times by -<code>nsBlockFrame::ReflowDirtyLines</code>. -<P> -The functions listed below the line for <code>nsBlockFrame::DoReflowInlineFrames</code> are its -callees. The numbers to the left of the function names are the numbers of -times these functions were in the callstack as callees of -<code>nsBlockFrame::DoReflowInlineFrames</code> and the corresponding percentages. In our example, of the 645 profiler hits under <code>nsBlockFrame::DoReflowInlineFrames</code> 545 were under <code>nsBlockFrame::ReflowInlineFrame</code>, 83 were under <code>nsBlockFrame::PlaceLine</code>, and so forth.<p> - -<b>NOTE:</b> If there are loops of execution or recursion, the numbers will -not add up and percentages can exceed 100%. If a function directly calls -itself "(self)" will be appended to the line, but indirect recursion will -not be marked. - -<h3>Bugs</h3> -The current build of Jprof has only been tested under Ubuntu 8.04 LTS, but -should work under any fairly modern linux distribution using GCC/GLIBC. -Please update this document with any known compatibilities/incompatibilities. -<p> -If you get an error:<p><code>Inconsistency detected by ld.so: dl-open.c: 260: dl_open_worker: Assertion `_dl_debug_initialize (0, args->nsid)->r_state == RT_CONSISTENT' failed! -</code><p>that means you've hit a timing hole in the version of glibc you're -running. See <a -href="http://sources.redhat.com/bugzilla/show_bug.cgi?id=4578">Redhat bug 4578</a>. -<!-- <h3>Update</h3> -<ul> -</ul> ---> - -</body> -</html> |