where in menuconfig is CONFIG_SMP located?-CodePudding

when I do 'make menuconfig' and search for a config variable by typing /PL011, the search result shows where in the menu hierarchy the config variables are located and what the prompt value is. But in some cases like CONFIG_SMP, even if I type /SMP, it shows only the this.

Symbol: SMP [=y]                                                                                               
Type  : bool                                                                                                   
Defined at arch/arm64/Kconfig:304

But this doesn't help because I cannot find the menu for CONFIG_SMP and set the value as I want. If I change the arch/arm64/Kconfig file directly, it causes build error. Where is this CONFIG_SMP in the menu hierarchy (linux-5.10.0) and how can I find this kind of menu item in general?

CodePudding user response：

I want to know how to get to the menu

The Kconfig definition for that config option has no menu prompt (in quotes).

config SMP
        def_bool y

So that's the reason why you couldn't (and will not) find (or be able to change) CONFIG_SMP in the menu.

My previous suggestion of "defining it manually in a defconfig" is not feasible.
Any prior definition of the config option (using #CONFIG_SMP is not set or CONFIG_SMP=n) in either a _defconfig file or the .config file was ineffective in overriding the default value specified by the Kconfig. On exit from the 'make xxx_defconfig' or 'make menuconfig' procedure, the .config file would always contain CONFIG_SMP=y.

I'm inclined to believe that such configuration options are intended to be fixed for that arch, and are not intended to be changed. Your unspecified "build failures" lend credence to this belief.

Perhaps you need to reevaluate why you want to change this config option from its default value.