[PATCH] D68820: win: Move Parallel.h off concrt to cross-platform code

Thu Oct 10 18:54:14 PDT 2019

aganea added a comment.

Looks slightly better without ConcRT, thanks Nico!
Here's some quick results showing the difference for the global hash parallelization in LLD, with MSVC OBJs. The algorithm is iterating on the .debug$T records, for a few thousands OBJs on 72 hyper threads:
(we're saving about 2 secs on this test)

**Before:**
F10214323: lld-link-concrt.PNG <https://reviews.llvm.org/F10214323>

**After:**
F10214327: lld-link-no-concrt.PNG <https://reviews.llvm.org/F10214327>

There's still this memory map lock eating half of the CPU time, I'm not too sure yet how to avoid it, if ever. Maybe touch the pages for the OBJ files in advance? Anyway, unrelated.
F10214332: lld-link-mmaccessfault-lock.PNG <https://reviews.llvm.org/F10214332>

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68820/new/

https://reviews.llvm.org/D68820