Display pre-test time

[christiangnrd]

Adds --debug-stats flag. This adds a printout of available memory as used by PTR to make runner # decisions before tests, a column that displays how long it took between worker running and testset starting, and on 1.11+, % of time spent in Julia precompilation.

Example:

julia> Pkg.test("Metal"; test_args=`--debug-stats --jobs=1 mtl`)
...
<Stuff>
...
Running 1 tests in parallel. If this is too many, specify the `--jobs=N` argument to the tests, or set the `JULIA_CPU_THREADS` environment variable.
Available memory: 24.014 GiB
                │   Test   │   Init   │ Compile │ ──────────────── CPU ──────────────── │
Test   (Worker) │ time (s) │ time (s) │   (%)   │ GC (s) │ GC % │ Alloc (MB) │ RSS (MB) │
mtl/metal   (1) │     4.62 │     6.17 │   88.00 │   0.18 │  3.9 │     779.42 │   952.48 │
mtl/size    (1) │     0.06 │     0.21 │   72.99 │   0.00 │  0.0 │       3.12 │   954.42 │

Test Summary: | Pass  Total   Time
  Overall     |  221    221  13.2s
    SUCCESS
     Testing Metal tests passed

Close #99

[maleadt]

I'm not sure that's worth an additional entry in the table. Maybe in verbose/debug mode?

[christiangnrd]

I'm not sure that's worth an additional entry in the table. Maybe in verbose/debug mode?

Yes if I do ever end up taking the time to turn this into a full PR I'd make it show up in either verbose or a debug mode.

[giordano]

I'm overall ok with this change, but I wonder whether this could be folded in --verbose instead of adding yet another flag to "get more information".

[christiangnrd]

I'm overall ok with this change, but I wonder whether this could be folded in --verbose instead of adding yet another flag to "get more information".

I would prefer merging into one flag. I originally added it as a separate flag because I didn't know if so much new output would be welcome as part of --verbose flag.

[giordano]

I would prefer this.

"this" being what exactly?

I originally added it as a separate flag because I didn't know if so much new output would be welcome as part of --verbose flag.

Maybe it's just me, but I read --verbose as "give me more output", and having a separate flag for "give me some other output, but not everything" feels a bit weird, because then both --verbose and --debug-stats separately are somewhat "verbose", just in different ways (one is "horizontally verbose", the other is "vertically verbose").

[christiangnrd]

"this" being what exactly?

I clarified (only --verbose) the original comment.

I've merged them and I can revert if desired

[giordano]

I feel like I was living better when I didn't know how much time was spent in compilation in the tests 😂

[christiangnrd]

I feel like I was living better when I didn't know how much time was spent in compilation in the tests 😂

Don’t look at the GPUArrays tests 😬

Also I suspect that the GPU testsuites aren’t all at 99% because the gpu kernel compilation isn’t included in that compilation percentage.