This can be used to compute the cost of coroutine operations. In the
end the cost of the function call is a few clock cycles, so it's pretty
cheap for now, but it may become more relevant as the coroutine code
is optimized.
For example, here are the results on my machine:
Function call 100000000 iterations: 0.173884 s
Yield 100000000 iterations: 8.445064 s
Lifecycle 1000000 iterations: 0.098445 s
Nesting 10000 iterations of 1000 depth each: 7.406431 s
One yield takes 83 nanoseconds, one enter takes 97 nanoseconds,
one coroutine allocation takes (roughly, since some of the allocations
in the nesting test do hit the pool) 739 nanoseconds:
(8.445064 - 0.173884) * 10^9 / 100000000 = 82.7
(0.098445 * 100 - 0.173884) * 10^9 / 100000000 = 96.7
(7.406431 * 10 - 0.173884) * 10^9 / 100000000 = 738.9
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>