makeworld.html

FreeBSD操作系统的详细使用手册

For example, if you accidentally deleted <tt class="FILENAME">/etc/magic</tt> as part of
the upgrade or merge of <tt class="FILENAME">/etc</tt>, the <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=file&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">file</span>(1)</span></a> command will
stop working. In this case, the fix would be to run:</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">cd /usr/src/usr.bin/file</kbd>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">make all install</kbd>
</pre>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="AEN28165" name="AEN28165">19.4.16 Questions</a></h2>

<div class="QANDASET">
<dl>
<dt>19.4.16.1. <a href="makeworld.html#Q19.4.16.1.">Do I need to re-make the world for
every change?</a></dt>

<dt>19.4.16.2. <a href="makeworld.html#Q19.4.16.2.">My compile failed with lots of signal
11 (or other signal number) errors. What has happened?</a></dt>

<dt>19.4.16.3. <a href="makeworld.html#Q19.4.16.3.">Can I remove <tt
class="FILENAME">/usr/obj</tt> when I have finished?</a></dt>

<dt>19.4.16.4. <a href="makeworld.html#Q19.4.16.4.">Can interrupted builds be
resumed?</a></dt>

<dt>19.4.16.5. <a href="makeworld.html#Q19.4.16.5.">How can I speed up making the
world?</a></dt>

<dt>19.4.16.6. <a href="makeworld.html#Q19.4.16.6.">What do I do if something goes
wrong?</a></dt>
</dl>

<div class="QANDAENTRY">
<div class="QUESTION">
<p><a id="Q19.4.16.1." name="Q19.4.16.1."></a><b>19.4.16.1.</b> Do I need to re-make the
world for every change?</p>
</div>

<div class="ANSWER">
<p><b></b>There is no easy answer to this one, as it depends on the nature of the change.
For example, if you just ran <b class="APPLICATION">CVSup</b>, and it has shown the
following files as being updated:</p>

<pre class="SCREEN">
<tt class="FILENAME">src/games/cribbage/instr.c</tt>
<tt class="FILENAME">src/games/sail/pl_main.c</tt>
<tt class="FILENAME">src/release/sysinstall/config.c</tt>
<tt class="FILENAME">src/release/sysinstall/media.c</tt>
<tt class="FILENAME">src/share/mk/bsd.port.mk</tt>
</pre>

<p>it probably is not worth rebuilding the entire world. You could just go to the
appropriate sub-directories and <tt class="COMMAND">make all install</tt>, and that's
about it. But if something major changed, for example <tt
class="FILENAME">src/lib/libc/stdlib</tt> then you should either re-make the world, or at
least those parts of it that are statically linked (as well as anything else you might
have added that is statically linked).</p>

<p>At the end of the day, it is your call. You might be happy re-making the world every
fortnight say, and let changes accumulate over that fortnight. Or you might want to
re-make just those things that have changed, and be confident you can spot all the
dependencies.</p>

<p>And, of course, this all depends on how often you want to upgrade, and whether you are
tracking FreeBSD-STABLE or FreeBSD-CURRENT.</p>
</div>
</div>

<div class="QANDAENTRY">
<div class="QUESTION">
<p><a id="Q19.4.16.2." name="Q19.4.16.2."></a><b>19.4.16.2.</b> My compile failed with
lots of signal 11 (or other signal number) errors. What has happened?</p>
</div>

<div class="ANSWER">
<p><b></b>This is normally indicative of hardware problems. (Re)making the world is an
effective way to stress test your hardware, and will frequently throw up memory problems.
These normally manifest themselves as the compiler mysteriously dying on receipt of
strange signals.</p>

<p>A sure indicator of this is if you can restart the make and it dies at a different
point in the process.</p>

<p>In this instance there is little you can do except start swapping around the
components in your machine to determine which one is failing.</p>
</div>
</div>

<div class="QANDAENTRY">
<div class="QUESTION">
<p><a id="Q19.4.16.3." name="Q19.4.16.3."></a><b>19.4.16.3.</b> Can I remove <tt
class="FILENAME">/usr/obj</tt> when I have finished?</p>
</div>

<div class="ANSWER">
<p><b></b>The short answer is yes.</p>

<p><tt class="FILENAME">/usr/obj</tt> contains all the object files that were produced
during the compilation phase. Normally, one of the first steps in the ``make buildworld''
process is to remove this directory and start afresh. In this case, keeping <tt
class="FILENAME">/usr/obj</tt> around after you have finished makes little sense, and
will free up a large chunk of disk space (currently about 340&nbsp;MB).</p>

<p>However, if you know what you are doing you can have ``make buildworld'' skip this
step. This will make subsequent builds run much faster, since most of sources will not
need to be recompiled. The flip side of this is that subtle dependency problems can creep
in, causing your build to fail in odd ways. This frequently generates noise on the
FreeBSD mailing lists, when one person complains that their build has failed, not
realizing that it is because they have tried to cut corners.</p>
</div>
</div>

<div class="QANDAENTRY">
<div class="QUESTION">
<p><a id="Q19.4.16.4." name="Q19.4.16.4."></a><b>19.4.16.4.</b> Can interrupted builds be
resumed?</p>
</div>

<div class="ANSWER">
<p><b></b>This depends on how far through the process you got before you found a
problem.</p>

<p><span class="emphasis"><i class="EMPHASIS">In general</i></span> (and this is not a
hard and fast rule) the ``make buildworld'' process builds new copies of essential tools
(such as <a href="http://www.FreeBSD.org/cgi/man.cgi?query=gcc&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">gcc</span>(1)</span></a>, and <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=make&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">make</span>(1)</span></a>) and the
system libraries. These tools and libraries are then installed. The new tools and
libraries are then used to rebuild themselves, and are installed again. The entire system
(now including regular user programs, such as <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=ls&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">ls</span>(1)</span></a> or <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=grep&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">grep</span>(1)</span></a>) is then
rebuilt with the new system files.</p>

<p>If you are at the last stage, and you know it (because you have looked through the
output that you were storing) then you can (fairly safely) do:</p>

<pre class="SCREEN">
<span class="emphasis"><i class="EMPHASIS">... fix the problem ...</i></span>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">cd /usr/src</kbd>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">make -DNOCLEAN all</kbd>
</pre>

<p>This will not undo the work of the previous ``make buildworld''.</p>

<p>If you see the message:</p>

<pre class="SCREEN">
--------------------------------------------------------------
Building everything..
--------------------------------------------------------------
</pre>

<p>in the ``make buildworld'' output then it is probably fairly safe to do so.</p>

<p>If you do not see that message, or you are not sure, then it is always better to be
safe than sorry, and restart the build from scratch.</p>
</div>
</div>

<div class="QANDAENTRY">
<div class="QUESTION">
<p><a id="Q19.4.16.5." name="Q19.4.16.5."></a><b>19.4.16.5.</b> How can I speed up making
the world?</p>
</div>

<div class="ANSWER">
<p><b></b></p>

<ul class="noindent">
<li>
<p>Run in single user mode.</p>
</li>

<li>
<p>Put the <tt class="FILENAME">/usr/src</tt> and <tt class="FILENAME">/usr/obj</tt>
directories on separate file systems held on separate disks. If possible, put these disks
on separate disk controllers.</p>
</li>

<li>
<p>Better still, put these file systems across multiple disks using the <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=ccd&sektion=4"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">ccd</span>(4)</span></a> (concatenated
disk driver) device.</p>
</li>

<li>
<p>Turn off profiling (set ``NOPROFILE=true'' in <tt
class="FILENAME">/etc/make.conf</tt>). You almost certainly do not need it.</p>
</li>

<li>
<p>Also in <tt class="FILENAME">/etc/make.conf</tt>, set <tt class="MAKEVAR">CFLAGS</tt>
to something like <var class="OPTION">-O -pipe</var>. The optimization <var
class="OPTION">-O2</var> is much slower, and the optimization difference between <var
class="OPTION">-O</var> and <var class="OPTION">-O2</var> is normally negligible. <var
class="OPTION">-pipe</var> lets the compiler use pipes rather than temporary files for
communication, which saves disk access (at the expense of memory).</p>
</li>

<li>
<p>Pass the <var class="OPTION">-j<var class="REPLACEABLE">n</var></var> option to <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=make&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">make</span>(1)</span></a> to run
multiple processes in parallel. This usually helps regardless of whether you have a
single or a multi processor machine.</p>
</li>

<li>
<p>The file system holding <tt class="FILENAME">/usr/src</tt> can be mounted (or
remounted) with the <var class="OPTION">noatime</var> option. This prevents the file
system from recording the file access time. You probably do not need this information
anyway.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">mount -u -o noatime /usr/src</kbd>
</pre>

<div class="WARNING">
<blockquote class="WARNING">
<p><b>Warning:</b> The example assumes <tt class="FILENAME">/usr/src</tt> is on its own
file system. If it is not (if it is a part of <tt class="FILENAME">/usr</tt> for example)
then you will need to use that file system mount point, and not <tt
class="FILENAME">/usr/src</tt>.</p>
</blockquote>
</div>
</li>

<li>
<p>The file system holding <tt class="FILENAME">/usr/obj</tt> can be mounted (or
remounted) with the <var class="OPTION">async</var> option. This causes disk writes to
happen asynchronously. In other words, the write completes immediately, and the data is
written to the disk a few seconds later. This allows writes to be clustered together, and
can be a dramatic performance boost.</p>

<div class="WARNING">
<blockquote class="WARNING">
<p><b>Warning:</b> Keep in mind that this option makes your file system more fragile.
With this option there is an increased chance that, should power fail, the file system
will be in an unrecoverable state when the machine restarts.</p>

<p>If <tt class="FILENAME">/usr/obj</tt> is the only thing on this file system then it is
not a problem. If you have other, valuable data on the same file system then ensure your
backups are fresh before you enable this option.</p>
</blockquote>
</div>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">mount -u -o async /usr/obj</kbd>
</pre>

<div class="WARNING">
<blockquote class="WARNING">
<p><b>Warning:</b> As above, if <tt class="FILENAME">/usr/obj</tt> is not on its own file
system, replace it in the example with the name of the appropriate mount point.</p>
</blockquote>
</div>
</li>
</ul>
</div>
</div>

<div class="QANDAENTRY">
<div class="QUESTION">
<p><a id="Q19.4.16.6." name="Q19.4.16.6."></a><b>19.4.16.6.</b> What do I do if something
goes wrong?</p>
</div>

<div class="ANSWER">
<p><b></b>Make absolutely sure your environment has no extraneous cruft from earlier
builds. This is simple enough.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">chflags -R noschg /usr/obj/usr</kbd>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">rm -rf /usr/obj/usr</kbd>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">cd /usr/src</kbd>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">make cleandir</kbd>
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">make cleandir</kbd>
</pre>

<p>Yes, <tt class="COMMAND">make cleandir</tt> really should be run twice.</p>

<p>Then restart the whole process, starting with <tt class="COMMAND">make
buildworld</tt>.</p>

<p>If you still have problems, send the error and the output of <tt class="COMMAND">uname
-a</tt> to <a href="http://lists.FreeBSD.org/mailman/listinfo/freebsd-questions"
target="_top">FreeBSD general questions mailing list</a>. Be prepared to answer other
questions about your setup!</p>
</div>
</div>
</div>
</div>
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