Andi requested that the json metrics be disabled on x86 in
https://lore.kernel.org/linux-perf-users/12e0deef-08db-445f-4958-bcd5c3e10367@xxxxxxxxxxxxxxx/#t
If we do that, do you still think the --topdown=<arg> modification is needed?
I guess it would have to report an error if someone requests --topdown=json-metrics on x86.