[PATCH] D76240: [Sanitizers][Test] If the default linker is LLD, disable threads

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

> CPU(s):                192

I didn't realize we were at the point where machines like this are commonly available.  I guess in that case, we end up with 40,000 threads, which is probably pushing the limit of what the machine can reasonably support.  I mean, I think it should be possible to fit that many threads onto a computer with a reasonable amount of memory, but it's at the order of magnitude where the amount of memory each thread is using starts to matter.  I think we might need to come up with some strategy to dynamically scale the number of threads each process is using for very parallel builds.

I mean, yes, we can do something like this patch for now, but users won't be happy when their builds start blowing up the same way.

>   I didn't really dig into the implementation of the parallel support library, but the following comment in include/llvm/Support/Parallel.h certainly seems a bit concerning:

The number of "tasks" is higher than the number of threads; the number of threads is controlled by the thread pool, and shouldn't exceed the number of cores, I think.  You should be able to check this using "ps".


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https://reviews.llvm.org/D76240