@@ -482,6 +482,36 @@ overview of their function and contents.
You must set this variable in the external environment in order
for it to work.
+
+ :term:`BB_PRESSURE_MAX_CPU`
+ The threshold for maximum CPU pressure before BitBake prevents the
+ scheduling of new tasks. Once the :term:`BB_PRESSURE_MAX_CPU` threshold
+ is exceeded, new tasks are not started until the pressure subsides to
+ below the threshold. If :term:`BB_PRESSURE_MAX_CPU` is not set, CPU
+ pressure is not monitored. A threshold can be set in ``conf/local.conf``
+ as:
+ ::
+
+ BB_PRESSURE_MAX_CPU = "500"
+
+ Information about how to set a suitable value and some other caveats to
+ consider can be found in the
+ :ref:`Reference Manual </ref-manual/variables:BB_PRESSURE_MAX_CPU>``
+
+ :term:`BB_PRESSURE_MAX_IO`
+ The threshold for maximum IO pressure experienced before BitBake
+ prevents the scheduling of new tasks. The IO pressure is regulated in the
+ same way as :term:`BB_PRESSURE_MAX_CPU`. At this point in time,
+ experiments show that IO pressure tends to be short-lived and regulating
+ just the CPU can help to reduce it.
+
+ :term:`BB_PRESSURE_MAX_MEMORY`
+ The threshold for maximum memory pressure experienced before BitBake
+ prevents the scheduling of new tasks. The memory pressure is regulated in
+ the same way as :term:`BB_PRESSURE_MAX_CPU`. Note that any memory
+ pressure indicates that a system is being pushed beyond it's capacity. At
+ this point in time, experiments show that memory pressure tends to be
+ short-lived and regulating just the CPU can help to reduce it.
:term:`BB_RUNFMT`
Specifies the name of the executable script files (i.e. run files)
Add the definitions for the BB_PRESSURE_MAX{CPU|IO|MEMORY} variables in the bitbake varibales glossary. Further information on how to determine a good threshold is added to the Yocto reference manual in the following commit: a9b58b3a6 ref-manual: add definition of BB_PRESSURE_MAX_CPU variable which has been cc-ed to the bitbake list. Signed-off-by: Aryaman Gupta <aryaman.gupta@windriver.com> Signed-off-by: Randy Macleod <Randy.Macleod@windriver.com> --- .../bitbake-user-manual-ref-variables.rst | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+)