[PATCH] D54889: Fiber support for thread sanitizer

[Dmitry Vyukov via Phabricator via llvm-commits]

dvyukov added a comment.

Since fiber support incurs slowdown for all current tsan users who don't use fibers, this is a hard decision.

I've prototyped a change which leaves fast_state and fast_synch_epoch in TLS (the only state accessed on fast path besides the clock):

  struct FastThreadState {
    FastState fast_state;
    u64 fast_synch_epoch;
  };
  
  __attribute__((tls_model("initial-exec")))
  extern THREADLOCAL char cur_thread_faststate1[];
  
  INLINE FastThreadState& cur_thread_faststate() {
    return *reinterpret_cast<FastThreadState *>(cur_thread_faststate1);
  }

But this seems to be even slower than just using the single pointer indirection.


Repository:
  rCRT Compiler Runtime

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D54889/new/

https://reviews.llvm.org/D54889