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CONFIG_NUM_PREEMPT_PRIORITIES¶
Number of preemptible priorities
Type: int
Help¶
Number of preemptible priorities available in the system. Gives access to priorities 0 to CONFIG_NUM_PREEMPT_PRIORITIES - 1.
This can be set to 0 to disable preemptible scheduling.
Each priority requires an extra 8 bytes of RAM. Each set of 32 extra total priorities require an extra 4 bytes and add one possible iteration to loops that search for the next thread to run.
The total number of priorities is
NUM_COOP_PRIORITIES + NUM_PREEMPT_PRIORITIES + 1
The extra one is for the idle thread, which must run at the lowest priority, and be the only thread at that priority.
Defaults¶
- 0 if !
MULTITHREADING - 15
Kconfig definition¶
At kernel/Kconfig:59
Included via Kconfig:10 → Kconfig.zephyr:31
Menu path: (top menu) → General Kernel Options
config NUM_PREEMPT_PRIORITIES
int
prompt "Number of preemptible priorities" if MULTITHREADING
range 0 128
default 0 if !MULTITHREADING
default 15
help
Number of preemptible priorities available in the system. Gives access
to priorities 0 to CONFIG_NUM_PREEMPT_PRIORITIES - 1.
This can be set to 0 to disable preemptible scheduling.
Each priority requires an extra 8 bytes of RAM. Each set of 32 extra
total priorities require an extra 4 bytes and add one possible
iteration to loops that search for the next thread to run.
The total number of priorities is
NUM_COOP_PRIORITIES + NUM_PREEMPT_PRIORITIES + 1
The extra one is for the idle thread, which must run at the lowest
priority, and be the only thread at that priority.
(Definitions include propagated dependencies, including from if’s and menus.)