[all-commits] [llvm/llvm-project] 47481c: [test] Deflake test/profile/ContinuousSyncMode/onl...

[Vedant Kumar via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 47481cbffbefb399e672cf056c15323917bf43bf
      https://github.com/llvm/llvm-project/commit/47481cbffbefb399e672cf056c15323917bf43bf
  Author: Vedant Kumar <vsk at apple.com>
  Date:   2020-07-02 (Thu, 02 Jul 2020)

  Changed paths:
    M compiler-rt/test/profile/ContinuousSyncMode/online-merging.c

  Log Message:
  -----------
  [test] Deflake test/profile/ContinuousSyncMode/online-merging.c

This test spawns 32 child processes which race to update counters on
shared memory pages. On some Apple-internal machines, two processes race
to perform an update in approximately 0.5% of the test runs, leading to
dropped counter updates. Deflake the test by using atomic increments.

Tested with:

```
$ for I in $(seq 1 1000); do echo ":: Test run $I..."; ./bin/llvm-lit projects/compiler-rt/test/profile/Profile-x86_64h/ContinuousSyncMode/online-merging.c -av || break; done
```

rdar://64956774