diff --git a/documentation/dev-manual/dev-manual-bsp-appendix.xml b/documentation/dev-manual/dev-manual-bsp-appendix.xml index 7b8dc6ead5..aecb24f725 100644 --- a/documentation/dev-manual/dev-manual-bsp-appendix.xml +++ b/documentation/dev-manual/dev-manual-bsp-appendix.xml @@ -562,9 +562,10 @@ You should also be sure any other variables in which you are interested are set. Some variables to consider are BB_NUMBER_THREADS and PARALLEL_MAKE, both of which can greatly reduce your build time - if you are using a multi-threaded development system (e.g. values of - 8 and j 6, respectively are optimal - for a development machine that has four available cores). + if your development system supports multiple cores. + For development systems that support multiple cores, a good rule of thumb is to set + both the BB_NUMBER_THREADS and PARALLEL_MAKE + variables to twice the number of cores your system supports. Update the bblayers.conf file so that it includes the path to your new BSP layer. In this example you need to include the pathname to meta-mymachine. diff --git a/documentation/dev-manual/dev-manual-kernel-appendix.xml b/documentation/dev-manual/dev-manual-kernel-appendix.xml index 7ac349b6e3..0f13344800 100644 --- a/documentation/dev-manual/dev-manual-kernel-appendix.xml +++ b/documentation/dev-manual/dev-manual-kernel-appendix.xml @@ -221,9 +221,9 @@ If your host development system supports multi-core and multi-thread capabilities, you can uncomment these statements and set the variables to significantly shorten the full build time. - As a guideline, set BB_NUMBER_THREADS to twice the number - of cores your machine supports and set PARALLEL_MAKE to one and - a half times the number of cores your machine supports. + As a guideline, set both BB_NUMBER_THREADS and + PARALLEL_MAKE to twice the number + of cores your machine supports. @@ -390,9 +390,8 @@ build time if your host supports multi-core and multi-thread capabilities: BB_NUMBER_THREADS and PARALLEL_MAKE. If the host system has multiple cores then you can optimize build time - by setting BB_NUMBER_THREADS to twice the number of - cores and setting PARALLEL_MAKE to one and a half times the - number of cores. + by setting both these variables to twice the number of + cores. Identify Your meta-kernel-dev Layer: The BBLAYERS variable in the bblayers.conf file found in the diff --git a/documentation/poky-ref-manual/ref-variables.xml b/documentation/poky-ref-manual/ref-variables.xml index 6843094fca..fc4fb9c5b1 100644 --- a/documentation/poky-ref-manual/ref-variables.xml +++ b/documentation/poky-ref-manual/ref-variables.xml @@ -927,7 +927,7 @@ This variable is usually in the form -j 4, where the number represents the maximum number of parallel threads make can run. If you development host supports multiple cores a good rule of thumb is to set - this variable to one and a half times the number of cores on the host. + this variable to twice the number of cores on the host. diff --git a/documentation/yocto-project-qs/yocto-project-qs.xml b/documentation/yocto-project-qs/yocto-project-qs.xml index fcbf3a1847..23e097b20f 100644 --- a/documentation/yocto-project-qs/yocto-project-qs.xml +++ b/documentation/yocto-project-qs/yocto-project-qs.xml @@ -410,11 +410,8 @@ PARALLEL_MAKE 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 the variable - BB_NUMBER_THREADS equal to twice the number of your + the lines and set both variables equal to twice the number of your host's processor cores. - Also, you could set the variable PARALLEL_MAKE equal to - 1.5 times the number of processor cores. Setting these variables can significantly shorten your build time.