Hacker News Reader

Comment by foxhill | Hacker News Reader

i think the true insanity lies within the mind of the developer whose build system depends on the number of jobs being ran in parallel..!

interesting academic exercise though. unless i'm mistaken, this will only detect up to 32 build jobs? i'd hate to see the Makefile that works for arbitrary values..

View on HN

Say one of your build rules generates a data file by performing some expensive computations. The parallelism is internal to the code (say, it's a Monte-Carlo simulation), so it should run on a lot of cores, but if you're doing it multiple times (with, say, different parameters) in parallel, you don't want the total number of threads spawned to be more than the machine has.

true, however my only complaint -

> you don't want the total number of threads spawned to be more than the machine has

that may not be necessarily true, and regardless, it might be a sane decision for yourself, but it might not be for others.

Why would you want to do it multiple times with different parameters in parallel? If your code can already scale to multiple cores, then just have each parameter set run one at a time, and you're already maximizing your CPU use.

Or integrate with make's jobserver as someone else has described.

It makes some sense to want to know this. You might know that your build process doesn't benefit from more than 4 jobs, and want to alert this to the developer who tries to use more.

Not all problems need a solution in code.

Awesome! This goes in my fortune file :D

I really have to echo the person who replied to you on a different thread and ask.. why? What do you think you're saving the user from exactly?

Please avoid such things. Useless warnings just create noise that mask real ones. Just this one may not matter, but the same rationality would apply to hundreds more.

Reply on news.ycombinator.com