On 2026-02-11 12:30, 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?
I was focused on x86, and didn't realize this was used by ARM. I think
I noticed the lack of check_wakeup_from_wait() calls on ARM. What did I
not notice? Are you saying wait.c should only be built for x86?
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.
Yes. I used CONFIG_WAIT since it matched wait.c. I considered
CONFIG_WAITQUEUE, but went with the shorter option. Re-using
CONFIG_VM_EVENT would be fine with me. I didn't use it in this
submission since the waitqueue functionality is more generic.
Regards,
Jason
