`@pstats` frequently reports 0 cpu cycles

```julia
julia> @pstats rand(1000,1000)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
┌ cpu-cycles 0.00e+00 47.4% # 0.0 cycles per ns
│ stalled-cycles-frontend 0.00e+00 47.4% # NaN% of cycles
└ stalled-cycles-backend 0.00e+00 47.4% # NaN% of cycles
┌ instructions 1.50e+07 52.7% # Inf insns per cycle
│ branch-instructions 2.38e+05 52.7% # 1.6% of insns
└ branch-misses 8.35e+01 52.7% # 0.0% of branch insns
┌ task-clock 3.81e+06 100.0% # 3.8 ms
│ context-switches 0.00e+00 100.0%
│ cpu-migrations 0.00e+00 100.0%
└ page-faults 0.00e+00 100.0%
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
```

This happens for me about ~20-50% of the time.

I'm not sure why it thinks it measured 47% of the running time but measured no cycles at all.