parse /proc/PID/stat file by cgroup hook properly

[vchlum]

Describe Bug or Feature

The cgroup hook does not parse /proc/PID/stat file correctly. It simply anticipates the space is always a delimiter.

The man proc states:

              (2) comm  %s
                     The filename of the executable, in parentheses.  Strings longer than TASK_COMM_LEN (16) char‐
                     acters (including the terminating null byte) are silently truncated.  This is visible whether
                     or not the executable is swapped out.

and having processes with space in the name:

==> /proc/3523/stat <==
3523 (UVM global queue) S 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 20 0 1 0 3814 0 0 18446744073709551615 0 0 0 0 0 0 0 214 7483647 0 1 0 0 17 14 0 0 0 0 0 0 0 0 0 0 0 0 0

==> /proc/3524/stat <==
3524 (UVM deferred release queue) S 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 20 0 1 0 3814 0 0 18446744073709551615 0 0 0 0 0 0 0 2147483647 0 1 0 0 17 16 0 0 0 0 0 0 0 0 0 0 0 0 0

==> /proc/3525/stat <==
3525 (UVM Tools Event Queue) S 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 20 0 1 0 3814 0 0 18446744073709551615 0 0 0 0 0 0 0 2147483647 0 1 0 0 17 19 0 0 0 0 0 0 0 0 0 0 0 0 0

can cause errors like:

03/07/2024 06:21:31;0080;pbs_python;Hook;pbs_python;['Traceback (most recent call last):', '  File "<embedded code object>", line 6425, in main', '  File "<embedded code object>", line 1041, in invoke_handler', '  File "<embedded code object>", line 1240, in _execjob_launch_handler', '  File "<embedded code object>", line 4019, in add_pids', '  File "<embedded code object>", line 3980, in _get_pids_in_sid', "ValueError: invalid literal for int() with base 10: 'S'"]

The bug is also reported in #2628

Describe Your Change

The change splits the line from the stat file by a suitable regex. Valid columns are \(.+\) or [^\s]+, and splitting is done by spaces around these columns.

Link to Design Doc

Attach Test and Valgrind Logs/Output

• Manual parsing test in python interpreter - simple regex testing:

>>> import re
>>> line="3523 (UVM global queue) S 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 20 0 1 0 3814 0 0 18446744073709551615 0 0 0 0 0 0 0 214 7483647 0 1 0 0 17 14 0 0 0 0 0 0 0 0 0 0 0 0 0"
>>> entries = re.split(r'\s+(\(.+\)|[^\s]+)\s+', line)
>>> print(entries)
['3523', '(UVM global queue)', 'S', '2', '0', '0', '0', '-1', '2129984', '0', '0', '0', '0', '0', '0', '0', '0', '20', '0', '1', '0', '3814', '0', '0', '18446744073709551615', '0', '0', '0', '0', '0', '0', '0', '214', '7483647', '0', '1', '0', '0', '17', '14', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0']

• PTL - test cgroups hook:
  ptl_cgroups_hook.txt

[bayucan]

Looks fine.

[shapovalovts]

Will this fix go to already released OpenPBS versions?