yocto-project-qs, ref-manual: Fixed core number defaults

Fixes [YOCTO #2528]

The defaults for BB_NUMBER_THREADS and PARALLEL_MAKE are now
automatically set to the build host's number of processor cores.
I updated the "Building and Image" section in the Quick Start
to state that.  I also updated the PARALLEL_MAKE variable.

(From yocto-docs rev: 2069c96d2410605c089da4eede2c7b4f9a7b704a)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/documentation/yocto-project-qs/yocto-project-qs.xml b/documentation/yocto-project-qs/yocto-project-qs.xml
index 96e2073..2419fcf 100644
--- a/documentation/yocto-project-qs/yocto-project-qs.xml
+++ b/documentation/yocto-project-qs/yocto-project-qs.xml
@@ -502,11 +502,12 @@
              Another couple of variables of interest are the
              <ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></ulink> and the
              <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></ulink> variables.
-             By default, these variables are commented out.
-             However, if you have a multi-core CPU you might want to uncomment
-             the lines and set both variables equal to twice the number of your
-             host's processor cores.
-             Setting these variables can significantly shorten your build time.
+             By default, these variables are set to how ever many processor
+             cores your build host uses.
+             However, if your build host uses multiple processor cores,
+             you should increase these settings to twice the number of
+             cores used.
+             Doing so can significantly shorten your build time.
          </para>
 
         <para>