On 11.02.2026 18:30, Andrew Cooper wrote:
> On 11/02/2026 5:01 pm, Jason Andryuk wrote:
>> wait.c is only used by vm_event.c.  Make CONFIG_VM_EVENT select
>> CONFIG_WAIT, and use CONFIG_WAIT to control building it.
>>
>> Provide stubs of functions called from common code.  entry.S needs an
>> ifdef to hide the symbol from the assembly.
>>
>> Also conditionalize .waitqueue_vcpu in struct vcpu to save space.
>>
>> Signed-off-by: Jason Andryuk <[email protected]>
> 
> I'd really rather see the API/ABI changes required to purge wait.c
> entirely, but I guess this will do in the short term.
> 
> Two things want further thought.
> 
> First, because ARM uses per-vCPU stacks not per-pCPU stacks, it doesn't
> need this infrastructure in the first place, but it looks like it's
> still compiled in and half wired up.  I suppose you don't notice because
> you compile out VM_EVENT on ARM too?

But if we want it compiled out altogether on Arm, ...

> Second CONFIG_WAIT isn't great name because there are many things it
> could be.  I'd be tempted to just reuse CONFIG_VM_EVENT and go without
> CONFIG_WAIT.  I do not want to see any new users of wait.c, and it will
> disappear at some point.

... don't we need a separate kconfig control, for it to be selected only
on x86 (or for it to be dependent on x86, and then imply-ed)? Imo
CONFIG_WAITQUEUE would be okay, as long as it won't have a prompt. We'd
then simply want to prevent further select-s / imply-s to appear.

Jan

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