Date: Sun, 13 Jan 2013 13:40:15 +0100 From: Marc Fonvieille <blackend@FreeBSD.org> To: Eitan Adler <eadler@FreeBSD.org> Cc: svn-doc-head@FreeBSD.org, svn-doc-all@FreeBSD.org, doc-committers@FreeBSD.org Subject: Re: svn commit: r40602 - head/en_US.ISO8859-1/books/faq Message-ID: <20130113124015.GB1505@emphyrio.blackend.org> In-Reply-To: <201301130611.r0D6BVNb031853@svn.freebsd.org> References: <201301130611.r0D6BVNb031853@svn.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Jan 13, 2013 at 06:11:31AM +0000, Eitan Adler wrote: > Author: eadler > Date: Sun Jan 13 06:11:30 2013 > New Revision: 40602 > URL: http://svnweb.freebsd.org/changeset/doc/40602 > > Log: > Update and expand on the why-kernel-big question in the handbook. > > PR: docs/174244 > Submitted by: Bas Smeelen <b.smeelen@ose.nl> > Approved by: bcr (mentor) > > Modified: > head/en_US.ISO8859-1/books/faq/book.xml > > Modified: head/en_US.ISO8859-1/books/faq/book.xml > ============================================================================== > --- head/en_US.ISO8859-1/books/faq/book.xml Sun Jan 13 06:09:00 2013 (r40601) > +++ head/en_US.ISO8859-1/books/faq/book.xml Sun Jan 13 06:11:30 2013 (r40602) > @@ -3297,17 +3297,27 @@ kern.timecounter.hardware: TSC -> i82 > </question> > > <answer> > - <para>Chances are, you compiled your kernel in <emphasis>debug > - mode</emphasis>. Kernels built in debug mode contain many > - symbols that are used for debugging, thus greatly increasing > - the size of the kernel. Note that there will be little or > - no performance decrease from running a debug kernel, and it > - is useful to keep one around in case of a system > - panic.</para> > - > - <para>However, if you are running low on disk space, or you > - simply do not want to run a debug kernel, make sure that > - both of the following are true:</para> > + <para>GENERIC kernels shipped with &os; and later are compiled ^^^ should be tagged > + in <emphasis>debug mode</emphasis>. Kernels built in debug mode ^^ 2 spaces? > + contain many symbols in separate files that are used for > + debugging, thus greatly increasing the size of > + <filename class="directory">/boot/kernel/</filename> > + Note that there will be little or no performance loss > + from running a debug kernel, and it is useful to keep one around > + in case of a system panic.</para> > + content & whitespace changes at the same time.... > + <para>However, if you are running low on disk space, there are > + different options to reduce the size of /boot/kernel/.</para> > + > + <para>If you do not want the symbol files to be installed, > + make sure you have the following line present in /etc/src.conf: missing </para> <programlisting> is a block element > + > + <programlisting>WITHOUT_KERNEL_SYMBOLS=yes</programlisting> > + <para> > + For more information see &man.src.conf.5</para> missing full stop > + > + <para>If you do not want to build a debug kernel, make > + sure that both of the following are true:</para> > > <itemizedlist> > <listitem> > @@ -3325,9 +3335,32 @@ kern.timecounter.hardware: TSC -> i82 > > <para>Either of the above settings will cause your kernel to > be built in debug mode. As long as you make sure you follow > - the steps above, you can build your kernel normally, and you > - should notice a fairly large size decrease; most kernels > - tend to be around 1.5 MB to 2 MB.</para> > + the steps above, you can build your kernel normally</para> missing full stop > + > + <para>If you want only the modules you use to be built > + and installed, make sure you have a line like below in > + /etc/make.conf:</para> > + missing <filename></filename> > + <programlisting>MODULES_OVERRIDE= <replaceable>accf_http ipfw</replaceable></programlisting> > + > + <para>Replace <emphasis>accf_httpd ipfw</emphasis> with a list > + of modules you need. Only these modules will be built. This ^^ ^^ 2spaces? > + does not only reduce the size of the kernel directory but > + also decreases the amount of time needed to build your kernel. > + For more information see > + <filename>/usr/share/examples/etc/make.conf</filename> > + </para> missing full stop > + > + <para>You can also remove unneeded devices from your kernel > + to further reduce the size. See ^^ > + <xref linkend="make-kernel"/> for more information.</para> > + > + <para>To put any of these options into effect you will have > + to <ulink url="&url.books.handbook;/kernelconfig-building.html">build and install</ulink> > + your new kernel.</para> > + > + <para>Most kernels (/boot/kernel/kernel) > + tend to be around 12 MB to 16 MB.</para> > </answer> > </qandaentry> > These changes have been reviewed? -- Marc
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130113124015.GB1505>