diff options
Diffstat (limited to 'documentation')
| -rw-r--r-- | documentation/dev-manual/dev-manual-start.xml | 7 | ||||
| -rw-r--r-- | documentation/ref-manual/closer-look.xml | 15 | ||||
| -rw-r--r-- | documentation/ref-manual/ref-structure.xml | 8 | ||||
| -rw-r--r-- | documentation/ref-manual/ref-variables.xml | 23 | ||||
| -rw-r--r-- | documentation/yocto-project-qs/yocto-project-qs.xml | 30 |
5 files changed, 33 insertions, 50 deletions
diff --git a/documentation/dev-manual/dev-manual-start.xml b/documentation/dev-manual/dev-manual-start.xml index df29302fdb..c3206b86f8 100644 --- a/documentation/dev-manual/dev-manual-start.xml +++ b/documentation/dev-manual/dev-manual-start.xml @@ -297,10 +297,9 @@ This file defines many aspects of the build environment including the target machine architecture through the <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'>MACHINE</ulink></filename> variable, - the development machine's processor use through the - <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'>BB_NUMBER_THREADS</ulink></filename> and - <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'>PARALLEL_MAKE</ulink></filename> variables, and - a centralized tarball download directory through the + the packaging format used during the build + (<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGE_CLASSES'><filename>PACKAGE_CLASSES</filename></ulink>), + and a centralized tarball download directory through the <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-DL_DIR'>DL_DIR</ulink></filename> variable.</para></listitem> <listitem><para> Build the image using the <filename>bitbake</filename> command. diff --git a/documentation/ref-manual/closer-look.xml b/documentation/ref-manual/closer-look.xml index c0c0d619a4..eaf07d665f 100644 --- a/documentation/ref-manual/closer-look.xml +++ b/documentation/ref-manual/closer-look.xml @@ -162,9 +162,10 @@ <itemizedlist> <listitem><para><emphasis>Parallelism Options:</emphasis> Controlled by the - <link linkend='var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></link> + <link linkend='var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></link>, + <link linkend='var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></link>, and - <link linkend='var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></link> + <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_NUMBER_PARSE_THREADS'><filename>BB_NUMBER_PARSE_THREADS</filename></ulink> variables.</para></listitem> <listitem><para><emphasis>Target Machine Selection:</emphasis> Controlled by the @@ -216,12 +217,10 @@ For example, suppose you had several build environments and they shared some common features. You can set these default build properties here. - A good example is perhaps the level of parallelism you want - to use through the - <link linkend='var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></link> - and - <link linkend='var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></link> - variables.</para> + A good example is perhaps the packaging format to use + through the + <link linkend='var-PACKAGE_CLASSES'><filename>PACKAGE_CLASSES</filename></link> + variable.</para> <para>One useful scenario for using the <filename>conf/site.conf</filename> file is to extend your <link linkend='var-BBPATH'><filename>BBPATH</filename></link> diff --git a/documentation/ref-manual/ref-structure.xml b/documentation/ref-manual/ref-structure.xml index 14419d3a84..1098006c73 100644 --- a/documentation/ref-manual/ref-structure.xml +++ b/documentation/ref-manual/ref-structure.xml @@ -467,12 +467,8 @@ <filename><link linkend='var-MACHINE'>MACHINE</link></filename> for which you want to build, which package types you wish to use (<link linkend='var-PACKAGE_CLASSES'><filename>PACKAGE_CLASSES</filename></link>), - the location from which you want to access downloaded files - (<filename><link linkend='var-DL_DIR'>DL_DIR</link></filename>), - and how you want your host machine to use resources - (<link linkend='var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></link> - and - <link linkend='var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></link>). + and the location from which you want to access downloaded files + (<filename><link linkend='var-DL_DIR'>DL_DIR</link></filename>). </para> <para> diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml index 7abad0460a..281c4e3e2d 100644 --- a/documentation/ref-manual/ref-variables.xml +++ b/documentation/ref-manual/ref-variables.xml @@ -729,20 +729,17 @@ <glossentry id='var-BB_NUMBER_THREADS'><glossterm><imagedata fileref="figures/define-generic.png" />BB_NUMBER_THREADS</glossterm> <info> - BB_NUMBER_THREADS[doc] = "The maximum number of tasks BitBake should run in parallel at any one time. A good rule of thumb is for this variable to be twice the number of cores." + BB_NUMBER_THREADS[doc] = "The maximum number of tasks BitBake should run in parallel at any one time. This variable is automatically configured to be equal to the number of build system cores." </info> <glossdef> <para> The maximum number of tasks BitBake should run in parallel at any one time. - If your host development system supports multiple cores, - a good rule of thumb is to have this variable be twice the - number of cores. - </para> - - <para> - The default value for <filename>BB_NUMBER_THREADS</filename> - is equal to the number of cores your build system has. + The OpenEmbedded build system automatically configures + this variable to be equal to the number of cores on the + build system. + To gain optimal parallelism, you should not have to + override this variable. </para> </glossdef> </glossentry> @@ -7380,11 +7377,9 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" </para> <para> - If your development host supports multiple cores, a good - rule of thumb is to set this variable to twice the number - of cores on the host. - If you do not set <filename>PARALLEL_MAKE</filename>, it - defaults to the number of cores your build system has. + The OpenEmbedded build system automatically sets this + variable to be equal to the number of cores the build + system uses. <note> Individual recipes might clear out this variable if the software being built has problems running its diff --git a/documentation/yocto-project-qs/yocto-project-qs.xml b/documentation/yocto-project-qs/yocto-project-qs.xml index 8fe9b766e6..f21558ebbd 100644 --- a/documentation/yocto-project-qs/yocto-project-qs.xml +++ b/documentation/yocto-project-qs/yocto-project-qs.xml @@ -509,15 +509,17 @@ </para> <para> - 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 set to the number of 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. + Another three variables of interest are the + <ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></ulink>, + <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></ulink>, + and + <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_NUMBER_PARSE_THREADS'><filename>BB_NUMBER_PARSE_THREADS</filename></ulink> + variables. + By default, these variables are optimally set based on the + number of processor cores your build host uses. + Although it is possible to override these variables, the + default values the OpenEmbedded build system derives provide you + with parallelism during the build. </para> <para> @@ -898,18 +900,10 @@ <filename>conf/local.conf</filename> configuration file in the Build Directory. You need to manually edit this file to specify the machine you - are building and to optimize your build time. - Here are the minimal changes to make: + are building: <literallayout class='monospaced'> - BB_NUMBER_THREADS = "8" - PARALLEL_MAKE = "-j 8" MACHINE ?= "beaglebone" </literallayout> - Briefly, set - <ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename></ulink> - and - <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename></ulink> to - twice your host processor's number of cores. </para> <para> |