[all-commits] [llvm/llvm-project] c5b94e: [profile] Support merge pool size >= 10

[Fangrui Song via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: c5b94ea265133a4a28006929643155fc8fbeafe6
      https://github.com/llvm/llvm-project/commit/c5b94ea265133a4a28006929643155fc8fbeafe6
  Author: Fangrui Song <maskray at google.com>
  Date:   2020-01-12 (Sun, 12 Jan 2020)

  Changed paths:
    M compiler-rt/lib/profile/InstrProfilingFile.c
    M compiler-rt/test/profile/instrprof-basic.c

  Log Message:
  -----------
  [profile] Support merge pool size >= 10

The executable acquires an advisory record lock (`fcntl(fd, F_SETLKW, *)`) on a profile file.
Merge pool size >= 10 may be beneficial when the concurrency is large.

Also fix a small problem about snprintf. It can cause the filename to be truncated after %m.

Reviewed By: davidxl

Differential Revision: https://reviews.llvm.org/D71970