svn commit: r53382 - head/en_US.ISO8859-1/books/porters-handbook/porting-dads

[Mark Linimon]

Author: linimon
Date: Sat Sep  7 20:52:18 2019
New Revision: 53382
URL: https://svnweb.freebsd.org/changeset/doc/53382

Log:
  Add a new section "Cluster-Specific Considerations" to discourage
  the use of -march=native by default.
  
  Approved by:		mat
  Differential Revision:	D20885

Modified:
  head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml

Modified: head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml
==============================================================================
--- head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml	Fri Sep  6 16:23:42 2019	(r53381)
+++ head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml	Sat Sep  7 20:52:18 2019	(r53382)
@@ -569,6 +569,24 @@ cc -o someprogram source1.o source2.o -L/usr/local/lib
 	</listitem>
       </itemizedlist>
     </sect2>
+
+    <sect2 xml:id="dads-arch-cluster">
+      <title>Cluster-Specific Considerations</title>
+
+      <itemizedlist>
+	<listitem>
+	  <para>Some ports attempt to tune themselves to the
+	    exact machine they are being built on by specifying
+	    <literal>-march=native</literal> to the compiler.
+	    This should be avoided: either list it under an
+	    off-by-default option, or delete it entirely.</para>
+
+	  <para> Otherwise, the default package produced by the
+	    build cluster might not run on every single machine
+ 	    of that <varname>ARCH</varname>.</para>
+	</listitem>
+      </itemizedlist>
+    </sect2>
   </sect1>
 
   <sect1 xml:id="dads-deprecated">