llvm-project

1a997e2a - [dsymutil] Reuse a single thread pool across architectures (#204691)

[dsymutil] Reuse a single thread pool across architectures (#204691) dsymutil links the architectures of a universal binary on a thread pool, and the parallel linker's DWARFLinkerImpl::link() then created a second pool to link each architecture's object files. With one such inner pool per architecture, dsymutil spun up more worker threads than the machine has cores. Add DWARFLinkerBase::setThreadPool() so the caller provides the pool. The parallel linker schedules the object files on it as a ThreadPoolTaskGroup. dsymutil hands over the pool it already uses to schedule the architectures, llvm-dwarfutil passes one sized by --num-threads, and the classic linker ignores it and manages its own threads (always 2 for the lockstep algorithm). The per-compile-unit cloning still runs on the global llvm::parallel executor, whose per-thread allocators are indexed by getThreadIndex(), so it can't move onto this pool.