[llvm-bugs] [Bug 45673] New: compiler-rt/test/profile/Posix/instrprof-gcov-parallel.test is flaky

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=45673

            Bug ID: 45673
           Summary: compiler-rt/test/profile/Posix/instrprof-gcov-parallel
                    .test is flaky
           Product: compiler-rt
           Version: 10.0
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: profile
          Assignee: unassignedbugs at nondot.org
          Reporter: slyfox at inbox.ru
                CC: llvm-bugs at lists.llvm.org, t-kawashima at fujitsu.com

Initially noticed as
http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/16358 where
parallel prof tests found only 6 of 7 samples.

Running locally I seem to observe similar effect:

"""
#!/bin/bash

rm -f instrprof-gcov-parallel.target.gcda instrprof-gcov-parallel.target.c.gcov
instrprof-gcov-parallel.target.gcda instrprof-gcov-parallel.target.gcno

/usr/lib/llvm/10/bin/clang            -o driver
instrprof-gcov-parallel.driver.c
/usr/lib/llvm/10/bin/clang --coverage -o target
instrprof-gcov-parallel.target.c

./driver ./target

llvm-cov gcov instrprof-gcov-parallel.target.gcda >/dev/null 2>&1
fgrep aaa++ instrprof-gcov-parallel.target.c.gcov
"""

"""
$ while :; do ./instrprof-gcov-parallel.test; done
      707:    7:    aaa++;
...
      101:    7:    aaa++;
...
      707:    7:    aaa++;
      707:    7:    aaa++;
...
      606:    7:    aaa++;
      707:    7:    aaa++;
      404:    7:    aaa++;
      707:    7:    aaa++;
"""

"""
$ clang --version
clang version 10.0.0
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/10/bin
"""

Could be some race in handling SIGCHLD and normal process execution?

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20200425/6b275e6c/attachment.html>