[bitbake-devel] [PATCH] bitbake-user-manual-execution.xml: Update parallelization note.
Robert P. J. Day
rpjday at crashcourse.ca
Wed Jun 18 15:22:38 UTC 2014
Update the note to explain that current versions of BitBake
automatically calculate the proper values for BB_NUMBER_THREADS and
PARALLEL_MAKE so you no longer need to set those values manually.
Signed-off-by: Robert P. J. Day <rpjday at crashcourse.ca>
---
diff --git a/doc/bitbake-user-manual/bitbake-user-manual-execution.xml b/doc/bitbake-user-manual/bitbake-user-manual-execution.xml
index 8514f23..6d49fb6 100644
--- a/doc/bitbake-user-manual/bitbake-user-manual-execution.xml
+++ b/doc/bitbake-user-manual/bitbake-user-manual-execution.xml
@@ -29,11 +29,23 @@
</para>
<note>
- Prior to executing BitBake, you should take advantage of parallel
- thread execution by setting the
- <link linkend='var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></link>
- variable in your <filename>local.conf</filename>
- configuration file.
+ In order to take advantage of parallel thread execution on your build
+ host, earlier versions of BitBake recommended setting the following
+ variables in your project's <filename>local.conf</filename> file,
+ based on your host's number of CPUs or multithreading
+ capability:
+ <literallayout class='monospaced'>
+ BB_NUMBER_THREADS ?= ...
+ PARALLEL_MAKE ?= ...
+ </literallayout>
+ The current version of BitBake now handles this automatically by
+ assigning default values to those variables as follows:
+ <literallayout class='monospaced'>
+ BB_NUMBER_THREADS ?= "${@oe.utils.cpu_count()}"
+ PARALLEL_MAKE ?= "-j ${@oe.utils.cpu_count()}"
+ </literallayout>
+ so you no longer need to worry about this, unless you specifically
+ want to override this for some reason.
</note>
<section id='parsing-the-base-configuration-metadata'>
--
========================================================================
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
========================================================================
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