[PATCH] D122922: [lld][common][lld-macho][lld-coff] Support per-thread allocators and StringSavers

[Vy Nguyen via Phabricator via llvm-commits]

oontvoo added a comment.

In D122922#3436091 <https://reviews.llvm.org/D122922#3436091>, @aganea wrote:

> Hello! Thanks for adding me :-) Interesting challenge!
> It's a bit sad that we have to do all this high-level/application-level memory management. Most modern allocators already support (lock-free) per-thread memory pools out-of-the-box, along with migration between threads and to the global pool/arena. This patch seems to be needed solely because we use `BumpPtrAllocator/SpecificBumpPtrAllocator`. I wonder how things would perform with just using `malloc()` instead + a modern underlying allocator (rpmalloc, mimalloc, ...). Memory locality brought by the bumpalloc is important, but it'd be interesting to compare benchmarks. FWIW there were discussions with @lattner at some point about integrating `rpmalloc` into the LLVM codebase, but I never got to post a RFC.

We did experimented with using a modern/threadsafe allocator here, specifically tcmalloc internally at google and found that it was pretty good (ie., no slower than the bump-ptr alloc). But conceptually the bump-alloc could be faster in simple cases so we thought it wouldn't hurt to use both when possible. (ie., have a thread safe bump allocator and a fast system malloc).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122922/new/

https://reviews.llvm.org/D122922