On 11/7/20 11:35 PM, Song Bao Hua (Barry Song) wrote:
Or do you want this ?(Code B) diff --git a/mm/Kconfig b/mm/Kconfig index 01b0ae0cd9d3..a7ff0d31afd5 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -836,6 +836,7 @@ config PERCPU_STATS config GUP_TEST bool "Enable infrastructure for get_user_pages()-related unit tests" + depends on DEBUG_FS help Provides /sys/kernel/debug/gup_test, which in turn provides a way to make ioctl calls that can launch kernel-based unit tests for @@ -853,6 +854,9 @@ config GUP_TEST See tools/testing/selftests/vm/gup_test.c +comment "GUP_TEST needs to have DEBUG_FS enabled" + depends on !GUP_TEST && !DEBUG_FS + config GUP_GET_PTE_LOW_HIGH bool
The above, please. It's your original patch, plus a way to display something if the "depends on" is not met.
To be honest, I am not a big fan of both of code A and B. I think "depends on" has clearly said everything the redundant comment wants to say.
It's not really just a "comment", in the sense of commenting the Kconfig sources. It actually has an effect, which is that it displays something in "make menuconfig". So it's not redundant, because it provides that output *instead* of hiding the option entirely, when !DEBUG_FS. Try it out, it's nice.
│ Symbol: GUP_TEST [=] │ Type : bool │ Defined at mm/Kconfig:837 │ Prompt: Enable infrastructure for get_user_pages()-related unit tests │ Depends on: DEBUG_FS [=n] │ Location: │ (1) -> Memory Management option Menuconfig shows GUP_TEST depends on DEBUG_FS and right now DEBUG_FS is "n". so it is impossible to enable GUP_TEST. "comment" is a good thing, but it is more likely to be used for a menu or a group of configurations to extend a bundle of things. On the other hand, If this particular case needs this comment, so do countless other configurations in hundreds of Kconfig files.
Well, maybe, yes. I personally find it quite difficult, having options appear and disappear on me, in this system. If they all had this "comment" behavior by default, to show up as a placeholder, I think it would be a better user experience. thanks, -- John Hubbard NVIDIA
