realtime:documentation:howto:debugging:no-cpu-idle
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realtime:documentation:howto:debugging:no-cpu-idle [2018/07/12 09:17] ebugden created |
realtime:documentation:howto:debugging:no-cpu-idle [2018/07/16 11:04] ebugden Specify that there are two different methods of modifying the kernel param |
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| Another way to make sure that the CPUs never go idle is to change the value of the Linux kernel boot parameter "idle". This technique does not prevent the idle task from executing, but it prevents the idle task from putting the CPUs in a low power idle state. This method is permanent for the duration of the system's execution. So, to allow the system to go idle again the parameter must be modified and the system must be restarted. | Another way to make sure that the CPUs never go idle is to change the value of the Linux kernel boot parameter "idle". This technique does not prevent the idle task from executing, but it prevents the idle task from putting the CPUs in a low power idle state. This method is permanent for the duration of the system's execution. So, to allow the system to go idle again the parameter must be modified and the system must be restarted. | ||
| - | To prevent the CPUs from going idle using the technique, the option idle=poll must be added to the command-line parameters passed to the kernel when it is executed on startup. This option forces the processor to poll when it has nothing to do instead of going into a low power idle state. More details about the "idle" option can be found in the Linux documentation about kernel parameters. | + | To prevent the CPUs from going idle using the technique, the option idle=poll must be added to the command-line parameters passed to the kernel when it is executed on startup. This option forces the processor to poll when it has nothing to do instead of going into a low power idle state. More details about the "idle" option can be found in the Linux documentation about kernel parameters. Two methods for changing the "idle" are presented below, a method where the new kernel parameter value is permanent until explicitly changed and a method where the kernel parameter applies for a single execution of the kernel. |
| ==== Change parameter permanently ==== | ==== Change parameter permanently ==== | ||
realtime/documentation/howto/debugging/no-cpu-idle.txt ยท Last modified: 2018/08/27 09:56 by ebugden
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