On 12.02.2026 20:14, Jason Andryuk wrote: > On 2026-02-12 02:38, Jan Beulich wrote: >> 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. > > ARM VM_EVENT=y won't link without wait.o. Undefined references to: > wake_up_nr > prepare_to_wait > finish_wait > destroy_waitqueue_head > init_waitqueue_head
Hmm, okay, assuming that then also actually works, ... > So I think that points to re-using my original patch, but with either > CONFIG_WAITQUEUE or CONFIG_VM_EVENT. Since CONFIG_VM_EVENT is the only > user, and we don't want further uses, I would use that. ... please do. Jan
