Make it easy to do multiple measurements on a given benchmark

[cdeil]

I've started to write benchmarks for Gammapy and decided that mostly high-level benchmarks running compute-heavy end-user analysis tasks are of interest and for each of those I'm interested in:

• CPU time
• Wall clock time
• Memory use

@mdboom Would it make sense to implement a mechanism that makes it easy to do several benchmarks (namely the three I mentioned) without having to write boilerplate code? Maybe via a decorator listing which measurements I want?

[mdboom]

This is a good idea. I'll self-assign if I find some free time to work on it, otherwise all patches welcome!

[erwanp]

I have a similar need : a single benchmark for the spectroscopy RADIS code can take up to 250s ; and computing it twice for PeakMemory and CPU-wall-time takes a lot of time.

Would it be possible and still accurate to measure both the PeakMemory and the CPU-wall-time on a single run ?