Index: doc/src/sgml/config.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/config.sgml,v
retrieving revision 1.233
diff -c -c -r1.233 config.sgml
*** doc/src/sgml/config.sgml	13 Nov 2009 22:43:39 -0000	1.233
--- doc/src/sgml/config.sgml	28 Nov 2009 16:12:46 -0000
***************
*** 1432,1437 ****
--- 1432,1439 ----
          The default is the first method in the above list that is supported
          by the platform.
          The <literal>open_</>* options also use <literal>O_DIRECT</> if available.
+         The utility <filename>src/tools/fsync</> in the PostgreSQL source tree
+         can do performance testing of various fsync methods.
          This parameter can only be set in the <filename>postgresql.conf</>
          file or on the server command line.
         </para>
Index: doc/src/sgml/wal.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v
retrieving revision 1.59
diff -c -c -r1.59 wal.sgml
*** doc/src/sgml/wal.sgml	9 Apr 2009 16:20:50 -0000	1.59
--- doc/src/sgml/wal.sgml	28 Nov 2009 16:12:57 -0000
***************
*** 86,91 ****
--- 86,93 ----
     ensure data integrity.  Avoid disk controllers that have non-battery-backed
     write caches.  At the drive level, disable write-back caching if the
     drive cannot guarantee the data will be written before shutdown.
+    You can test for reliable I/O subsystem behavior using <ulink
+    url="http://brad.livejournal.com/2116715.html">diskchecker.pl</ulink>.
    </para>
  
    <para>