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

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai added a comment.

While I agree that the more general issue of scaling LLVM's (and particularly LLD's) parallelism is something we should consider tackling, I still think there is value in proceeding with something along the lines of this patch in the interim.
For users that have very parallel builds, there are mitigations available:

- Presumably, most builds do not link such a large number of binaries that this is a serious problem
- Even for builds that do link a large number of binaries, the cmake/ninja build system does provide the ability to scale down the number of parallel link jobs as someone mentioned in the comments above

However, the only recourse we currently have when it comes to running lit tests when LLD is the default linker is to reduce the number of processes available to lit using something like `-DLLVM_LIT_ARGS=--threads=N` for some N that won't cause such failures. This will have the undesired effect of reducing parallelism for tests that don't even use the linker (i.e. the vast majority of them). I suppose another workaround would be to test the sanitizers separately and pass in lit arguments accordingly, but that is even more inconvenient.


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  https://reviews.llvm.org/D76240/new/

https://reviews.llvm.org/D76240