[Toybox] toybox build first-world problems

[Rob Landley]

On 3/5/23 13:01, Rob Landley wrote:
> 8-core mac is a new use case. It probably needs to fall back to the old pre-n
> behavior (like 80% efficiency on average on my 4x processor laptop I'd guess?)
> instead just not using -n when "wait -n" errors (which has side effects).

I reimplemented the old round-robin $PID wait as the fallback when there's no
-n. And it's more like 90% efficiency in my testing on my laptop: you can see
the tops of the CPU usage bars flutter a bit vs solid in the other one, but it
keeps them all mostly busy. (I used to compensate by launching N+1 processes,
but didn't put that part back. Not likely to make a measurable difference on >8
processors anyway.)

>> this is a lot less noticeable when you have 128 cores,
>> because that's "most of defconfig" anyway. but when you only [world's
>> tiniest violin] have 10 cores, it's really noticeable [even without
>> that patch] the first 10 dots appear instantaneously, but the
>> remaining ones appear one-by-one [which is what made me ask ps "what's
>> actually going on?"]. there's basically just one compile job running
>> at any given time after the first batch on the Mac. it's not _quite_
>> serial though, because on the 128-core box i do see ~4 cc jobs at a
>> time after the initial 128 job goldrush.
> 
> And that's a separate issue. I admit I have 4 cores here so wouldn't notice a
> limit of more than that, but... what?

Did commit dd56ea086435 address this part too, or is there more to do?

Rob