On 22/09/21 13:22, Marc Zyngier wrote:
Frankly, this is a job for BPF and the tracing subsystem, not for some hardcoded syndrome accounting. It would allow to extract meaningful information, prevent bloat, and crucially make it optional. Even empty trace points like the ones used in the scheduler would be infinitely better than this (load your own module that hooks into these trace points, expose the data you want, any way you want).
I agree. I had left out for later the similar series you had for x86, but I felt the same as Marc; even just counting the number of occurrences of each exit reason is a nontrivial amount of memory to spend on each vCPU.
Paolo
